'Our harmless emissions of trifling quantities of carbon dioxide cannot possibly acidify the oceans.

Carbon dioxide

Carbon dioxide dissolves in the ocean to form carbonic acid (H2CO3), bicarbonate (HCO3−) and carbonate (CO32−).

Carbon dioxide

Most of the CO 2 taken up by the ocean, which is about 30% of the total released into the atmosphere, forms carbonic acid in equilibrium with bicarbonate.

Carbon dioxide

Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid.

Carbon dioxide

"Marine calcifiers exhibit mixed responses to CO 2-induced ocean acidification".

Marine pollution

These rising levels of carbon dioxide are acidifying the oceans.


The current debate on the connection between CO2 emissions and climate change has largely overlooked an independent and equally serious problem, the increasing acidity of our oceans.

Carbon dioxide

As the concentration of carbon dioxide increases in the atmosphere, the increased uptake of carbon dioxide into the oceans is causing a measurable decrease in the pH of the oceans, which is referred to as ocean acidification.

Carbon dioxide

Also, the Intergovernmental Panel on Climate Change (IPCC) writes in their Climate Change 2007: Synthesis Report: "The uptake of anthropogenic carbon since 1750 has led to the ocean becoming more acidic with an average decrease in pH of 0.1 units.

Ocean acidification

Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO 2) from the atmosphere.

Ocean acidification

This will cause an elevation of ocean alkalinity, leading to the enhancement of the ocean as a reservoir for CO 2 with implications for climate change as more CO 2 leaves the atmosphere for the ocean.

Scientific consensus on climate change:184

Scientific consensus on climate change

They state further that the "continuing reliance on combustion of fossil fuels as the world's primary source of energy will lead to much higher atmospheric concentrations of greenhouse gases, which will, in turn, cause significant increases in surface temperature, sea level, ocean acidification, and their related consequences to the environment and society".


Last December, the respected  journal “Oceanography” published projections (see graphic below) for this rising acidity, measured by falling pH

Ocean acidification

Limiting global warming to below 2 °C would imply a reduction in surface ocean pH of 0.16 from pre-industrial levels.

Ocean acidification

It is expected to drop by a further 0.3 to 0.5 pH units (an additional doubling to tripling of today's post-industrial acid concentrations) by 2100 as the oceans absorb more anthropogenic CO 2, the impacts being most severe for coral reefs and the Southern Ocean.

Ocean acidification

"Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset".

Ocean acidification

Between 1751 and 1996, surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14, representing an increase of almost 30% in H+ ion concentration in the world's oceans.

Ocean acidification

"Rising levels of acids in seas may endanger marine life, says study".


Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores.

Hockey stick controversy

For his postdoctoral research, Mann joined Bradley and tree ring specialist Malcolm K. Hughes to develop a new statistical approach to reconstruct underlying spatial patterns of temperature variation combining diverse datasets of proxy information covering different periods across the globe, including a rich resource of tree ring networks for some areas and sparser proxies such as lake sediments, ice cores and corals, as well as some historical records.

Hockey stick controversy

The Mann, Bradley & Hughes 1998 (MBH98) multiproxy study on "Global-scale temperature patterns and climate forcing over the past six centuries" was submitted to the journal Nature on 9 May 1997, accepted on 27 February 1998 and published on 23 April 1998.

Paleoclimatology

Paleoclimatology uses a variety of proxy methods from the Earth and life sciences to obtain data previously preserved within rocks, sediments, boreholes, ice sheets, tree rings, corals, shells, and microfossils.

Proxy (climate)

Examples of proxies include ice cores, tree rings, sub-fossil pollen, boreholes, corals, lake and ocean sediments, and carbonate speleothems.

Proxy (climate)

Several studies, including and have compiled box and gravity cores in the North Pacific analyzing them for palynological content to determine the distribution of dinocysts and their relationships with sea surface temperature, salinity, productivity and upwelling.


They all confirm the original hockey stick conclusion: the 20th century is the warmest in the last 1000 years and that warming was most dramatic after 1920.

Effects of global warming

A wide variety of temperature proxies together prove that the 20th century was the hottest recorded in the last 2,000 years.

Global warming

Multiple independently produced instrumental datasets confirm that the 2009–2018 decade was 0.93 ± 0.07 °C warmer than the pre-industrial baseline (1850–1900).

Global warming

The period from 1983 to 2012 was likely the warmest 30-year period of the last 1400 years in the Northern Hemisphere, where such assessment is possible (medium confidence).

Hockey stick controversy

They concluded that although the 20th century was almost certainly the warmest of the millennium, the amount of anthropogenic warming remains uncertain."

Intergovernmental Panel on Climate Change:113

They judge that global mean surface air temperature has increased by 0.3 to 0.6 °C over the last 100 years, broadly consistent with prediction of climate models, but also of the same magnitude as natural climate variability.


A number of independent investigations from different countries, universities and government bodies have investigated the stolen emails and found no evidence of wrong doing.

Climatic Research Unit email controversy:244

The Office of the Inspector General (OIG) of the National Science Foundation closed an investigation on 15 August 2011 that exonerated Michael Mann of Pennsylvania State University of charges of scientific misconduct.

Climatic Research Unit email controversy:247

The OIP findings confirmed the university panel's conclusions which cleared Mann of any wrongdoing, and it stated "Lacking any evidence of research misconduct, as defined under the NSF Research Misconduct Regulation, we are closing the investigation with no further action."

Climatic Research Unit email controversy:7

Eight committees investigated the allegations and published reports, finding no evidence of fraud or scientific misconduct.

Nepal

The Commission for the Investigation of Abuse of Authority is an independent investigative agency that investigates and prosecutes cases related to corruption and bribery, in addition to the abuse of authority by government officials and officeholders.

Russian interference in the 2016 United States elections:197

By January 2017, a multi-agency investigation, conducted by the FBI, the CIA, the NSA, the Justice Department, the Financial Crimes Enforcement Network and representatives of the DNI, was underway looking into how the Russian government may have secretly financed efforts to help Trump win the election had been conducted over several months by six federal agencies.


Focusing on a few suggestive emails, taken out of context, merely serves to distract from the wealth of empirical evidence for man-made global warming.

Climate change denial

Despite leaked emails during the Climatic Research Unit email controversy, as well as multinational, independent research on the topic, no evidence of such a conspiracy has been presented, and strong consensus exists among scientists from a multitude of political, social, organizational and national backgrounds about the extent and cause of climate change.

Climate change denial

The efforts of Al Gore and other environmental campaigns have focused on the effects of global warming and have managed to increase awareness and concern, but despite these efforts, the number of Americans believing humans are the cause of global warming was holding steady at 61% in 2007, and those believing the popular media was understating the issue remained about 35%.

Climate change denial

Most of the few statements that critics claim as evidence of malfeasance seem to have more innocent explanations that make sense in the context of scientists conversing privately and informally."

Climate change denial

Science education is under attack… by climate change deniers, who ignore a mountain of evidence gathered over the last fifty years that the planet is warming and that humans are largely responsible.

Global warming

The warming evident in the instrumental temperature record is consistent with a wide range of observations, documented by many independent scientific groups; for example, in most continental regions the frequency and intensity of heavy precipitation has increased.


“[T]he 1079 emails and 72 documents seem indeed evidence of a scandal  involving most of the most prominent scientists pushing the man-made  warming theory - a scandal that is one of the greatest in modern  science.

Climatic Research Unit email controversy:278

Writing for Newsweek, journalist Sharon Begley called the controversy a "highly orchestrated, manufactured scandal", noting that the public was unlikely to change their mind.

Climatic Research Unit email controversy:286

He said that it was not a single scandal, but "a sustained and coordinated campaign" aimed at undermining the credibility of the science.

Climatic Research Unit email controversy:303

An editorial in Nature said that many in the media "were led by the nose, by those with a clear agenda, to a sizzling scandal that steadily defused as the true facts and context were made clear".

Climatic Research Unit email controversy:552

In blogs, talk radio and other new media, we are told that the warnings about future global warming issued by the national science academies, scientific societies, and governments of all the leading nations are not only mistaken, but based on a hoax, indeed a conspiracy that must involve thousands of respected researchers.

Climatic Research Unit email controversy:70

In this context, John Tierney of The New York Times wrote: "these researchers, some of the most prominent climate experts in Britain and America, seem so focused on winning the public-relations war that they exaggerate their certitude – and ultimately undermine their own cause".


It found the scientists' rigour and honesty are not in doubt, and their behaviour did not prejudice the IPCC's conclusions, though they did fail to display the proper degree of openness.

Climatic Research Unit email controversy:135

Scientific integrity demands robust, independent peer review, however, and AAAS therefore emphasised that investigations are appropriate whenever significant questions are raised regarding the transparency and rigour of the scientific method, the peer-review process, or the responsibility of individual scientists.

Climatic Research Unit email controversy:163

The committee criticised a "culture of non-disclosure at CRU" and a general lack of transparency in climate science where scientific papers had usually not included all the data and code used in reconstructions.

Climatic Research Unit email controversy:239

The report, issued on 18 February 2011, cleared the researchers and "did not find any evidence that NOAA inappropriately manipulated data or failed to adhere to appropriate peer review procedures".

Global warming conspiracy theory

The Muir Russell report stated that the scientists' "rigor and honesty as scientists are not in doubt," that the investigators "did not find any evidence of behavior that might undermine the conclusions of the IPCC assessments," but that there had been "a consistent pattern of failing to display the proper degree of openness."

Intergovernmental Panel on Climate Change:33

This document also states that IPCC will do this work by assessing "on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis" of these topics.


[…] Constant 24-7  media coverage of every significant storm worldwide just makes it seem  that way.”

2003 invasion of Iraq

This attracted considerable media coverage at the time.

Daniel Bryan

"Radican's ROH Respect Is Earned Report 7/20: ongoing "virtual time" coverage of PPV".

Gulf War

At the same time, the war's coverage was new in its instantaneousness.

Hurricane Sandy

The severe and widespread damage the storm caused in the United States, as well as its unusual merger with a frontal system, resulted in the nicknaming of the hurricane "Superstorm Sandy" by the media, public officials, and several organizations, including U.S. government agencies.

Hurricane Sandy

As coverage continued, several media outlets began eschewing this term in favor of "superstorm".


It is unclear whether global warming is increasing hurricane frequency but there is increasing evidence that warming increases hurricane intensity.

Effects of global warming

more intense droughts and tropical cyclones) are more uncertain.

Extreme weather

In recent years, growing evidence suggests that human-induced global warming is increasing the periodicity and intensity of some extreme weather events.

Global warming

The maximum rainfall and wind speed from hurricanes and typhoons are likely increasing.

Global warming

The warming evident in the instrumental temperature record is consistent with a wide range of observations, documented by many independent scientific groups; for example, in most continental regions the frequency and intensity of heavy precipitation has increased.

Global warming

The effects of global warming include rising sea levels, regional changes in precipitation, more frequent extreme weather events such as heat waves, and expansion of deserts.


Al Gore's film was "broadly accurate" according to an expert witness called when an attempt was made through the courts to prevent the film being shown in schools.

Al Gore

In a 2007 court case, a British judge said that while he had "no doubt ...the film was broadly accurate" and its "four main scientific hypotheses ...are supported by a vast quantity of research", he upheld nine of a "long schedule" of alleged errors presented to the court.

Al Gore

He ruled that the film could be shown to schoolchildren in the UK if guidance notes given to teachers were amended to balance out the film's one-sided political views.

An Inconvenient Truth

The plaintiffs sought an injunction preventing the screening of the film in English schools, arguing that by law schools are forbidden to promote partisan political views and, when dealing with political issues, are required to provide a balanced presentation of opposing views.

An Inconvenient Truth

The judge ruled that An Inconvenient Truth contained nine scientific errors and thus must be accompanied by an explanation of those errors before being shown to school children.

An Inconvenient Truth

Gore climate documentary to be shown in schools.


While there are minor errors in An Inconvenient Truth, the main truths presented - evidence to show mankind is causing global warming and its various impacts is consistent with peer reviewed science.

An Inconvenient Truth

The survey, published as an editorial in the journal Science, found that every article either supported the human-caused global warming consensus or did not comment on it.

An Inconvenient Truth

All 19 climate scientists who had seen the movie or had read the homonymous book said that Gore accurately conveyed the science, with few errors.

An Inconvenient Truth

Gore's presentation was the most powerful and clear explanation of global warming I had ever seen.

An Inconvenient Truth

"Judge attacks nine errors in Al Gore's 'alarmist' climate change film".

Global warming

In the scientific literature, there is an overwhelming consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases.


While there are isolated cases of growing glaciers, the overwhelming trend in glaciers worldwide is retreat.

Glacier

Following the Little Ice Age's end around 1850, glaciers around the Earth have retreated substantially.

Glacier

A slight cooling led to the advance of many alpine glaciers between 1950 and 1985, but since 1985 glacier retreat and mass loss has become larger and increasingly ubiquitous.

Himalayas

In recent years, scientists have monitored a notable increase in the rate of glacier retreat across the region as a result of climate change.

Holocene glacial retreat

The Holocene glacial retreat is a geographical phenomenon that involved the global deglaciation of glaciers that previously had advanced during the Last Glacial Maximum.

Subantarctic

Glaciers are currently retreating at significant rates throughout the southern hemisphere.


In fact, the global melt rate has been accelerating since the mid-1970s.

Global warming

This effect results in the increased absorption of radiation that accelerates melting."

Sea level rise

This acceleration is due mostly to human-caused global warming, which is driving thermal expansion of seawater and the melting of land-based ice sheets and glaciers.

Sea level rise

"Antarctica ice melt has accelerated by 280% in the last 4 decades".

Sea level rise

However scientists have found that ice is being lost, and at an accelerating rate.

Sea level rise

A 2018 systematic review study estimated that ice loss across the entire continent was 43 gigatons (Gt) per year on average during the period from 1992 to 2002, but has accelerated to an average of 220 Gt per year during the five years from 2012 to 2017.


Cosmic ray counts have increased over the past 50 years, so if they do influence global temperatures, they are having a cooling effect.

Eocene

Oxygen isotope analysis showed a large negative change in the proportion of heavier oxygen isotopes to lighter oxygen isotopes, which indicates an increase in global temperatures.

Global warming

The main balancing feedback to global temperature change is radiative cooling to space as infrared radiation, which increases strongly with increasing temperature.

Global warming

Currently, surface temperatures are rising by about 0.2 °C per decade.

Global warming

IPCC AR5 SYR Glossary 2014, p. 124: Global warming refers to the gradual increase, observed or projected, in global surface temperature, as one of the consequences of radiative forcing caused by anthropogenic emissions.

Global warming

Globally, these effects are estimated to have led to a slight cooling, dominated by an increase in surface albedo.


By regulating the Earth’s cloud cover, the Sun  can turn the temperature up and down. ...

Climate change (general concept)

These variations can affect global average surface temperature by redistributing heat between the deep ocean and the atmosphere and/or by altering the cloud/water vapor/sea ice distribution which can affect the total energy budget of the earth.

Earth

This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature.

Global warming

If cloud cover increases, more sunlight will be reflected back into space, cooling the planet.

Global warming

Without the Earth's atmosphere, the Earth's average temperature would be well below the freezing temperature of water.

Sun

The temperature of the photosphere is approximately 6,000 K, whereas the temperature of the corona reaches 1,000,000–2,000,000 K. The high temperature of the corona shows that it is heated by something other than direct heat conduction from the photosphere.


While the link between cosmic rays and cloud cover is yet to be confirmed, more importantly, there has been no correlation between cosmic rays and global temperatures over the last 30 years of global warming.

Attribution of recent climate change:231

Attribution of recent climate change

Together with the lack of a proven physical mechanism and the plausibility of other causal factors affecting changes in cloud cover, this makes the association between galactic cosmic ray-induced changes in aerosol and cloud formation controversial Studies by Lockwood and Fröhlich (2007) and Sloan and Wolfendale (2008) found no relation between warming in recent decades and cosmic rays.

Cosmic ray

Despite Svensmark's assertions, galactic cosmic rays have shown no statistically significant influence on changes in cloud cover, and have been demonstrated in studies to have no causal relationship to changes in global temperature.

Henrik Svensmark

Sloan and Wolfendale (2013) demonstrated that while temperature models showed a small correlation every 22 years, less than 14 percent of global warming since the 1950s could be attributed to cosmic ray rate.

Henrik Svensmark

Another 2013 study found, contrary to Svensmark's claims, "no statistically significant correlations between cosmic rays and global albedo or globally averaged cloud height."

Henrik Svensmark

In 2013, a laboratory study by Svensmark, Pepke and Pedersen published in Physics Letters A showed, that there is in fact a correlation between cosmic rays and the formation of aerosols of the type that seed clouds.


In fact, in recent years when cosmic rays should have been having their largest cooling effect on record, temperatures have been at their highest on record.

Climate change (general concept)

On average, such eruptions occur several times per century, and cause cooling (by partially blocking the transmission of solar radiation to the Earth's surface) for a period of several years.

Instrumental temperature record

Even accounting for the presence of internal climate variability, recent years rank among the warmest on record.

Mercury (planet)

Having almost no atmosphere to retain heat, it has surface temperatures that vary diurnally more than on any other planet in the Solar System, ranging from 100 K (−173 °C; −280 °F) at night to 700 K (427 °C; 800 °F) during the day across the equatorial regions.

Solar System

It is the hottest planet, with surface temperatures over 400 °C (752 °F), most likely due to the amount of greenhouse gases in the atmosphere.

Venus

The actual temperatures are not known, because the size of the hot spots could not be measured, but are likely to have been in the 800–1,100 K (527–827 °C; 980–1,520 °F) range, relative to a normal temperature of 740 K (467 °C; 872 °F).


Hypothetically, an increasing solar magnetic field could deflect galactic cosmic rays, which hypothetically seed low-level clouds, thus decreasing the Earth's reflectivity and causing global warming.

Attribution of recent climate change:224

Attribution of recent climate change

Henrik Svensmark has suggested that the magnetic activity of the sun deflects cosmic rays, and that this may influence the generation of cloud condensation nuclei, and thereby have an effect on the climate.

Cosmic ray

In addition, the Earth's magnetic field acts to deflect cosmic rays from its surface, giving rise to the observation that the flux is apparently dependent on latitude, longitude, and azimuth angle.

Cosmic ray

Danish physicist Henrik Svensmark has controversially argued that because solar variation modulates the cosmic ray flux on Earth, they would consequently affect the rate of cloud formation and hence be an indirect cause of global warming.

Global warming

Global warming

This effect also causes droplets to be of more uniform size, which reduces the growth of raindrops and makes clouds more reflective to incoming sunlight.


Steve McIntyre noticed a strange  discontinuity in US temperature data, occurring around January 2000.

Steve McIntyre

In 2002, McIntyre became interested in climate science after a leaflet from the Canadian government warning of the dangers of global warming was delivered to his residence.

Steve McIntyre

McIntyre states that he noticed discrepancies in climate science papers that reminded him of the false prospectus that had duped investors involved in the Bre-X gold mining scandal.

Steve McIntyre

In 2007, McIntyre started auditing the various corrections made to temperature records, in particular those relating to the urban heat island effect.

Steve McIntyre

He discovered a discontinuity in some U.S. records in the Goddard Institute for Space Studies (GISS) dataset starting in January 2000.

Steve McIntyre

The adjustment reduced the average temperatures for the continental United States by about 0.15 °C during the years 2000-2006.


As a result, "The warmest  year on US record is now 1934.

2000s (decade)

This decade is on track to become the warmest since records began in 1850, and 2009 could rank among the top-five warmest years, the U.N. weather agency reported Tuesday on the second day of a pivotal 192-nation climate conference.

Climate change in the United States

2013 was the warmest year ever in the contiguous United States and about one-third of all Americans experienced 10 days or more of 100-degree heat.

Climate change in the United States

In 2012, the United States experienced its warmest year on record.

Climate change in the United States

The U.S. had its warmest March–May on record in 2012.

New York City

The warmest year on record is 2012, with a mean temperature of 57.4 °F (14.1 °C).


(2012 is now the hottest by a wide margin), but the USA only comprises 2% of the globe.

Florida

With a population of more than 18 million, according to the 2010 census, Florida is the most populous state in the southeastern United States and the third-most populous in the United States.

Florida

Florida is west of The Bahamas and 90 miles (140 km) north of Cuba.

Florida

With an average daily temperature of 70.7 °F (21.5 °C), it is the warmest state in the U.S.

Florida

In 2012, 75% of the population lived within 10 miles (16 km) of the coastline.

Florida

This is down from a peak of 17.1% in 2012.


"Austria is today seeing its earliest snowfall in history with 30 to 40 centimetres already predicted in the mountains.

Austria

From 1925 to 1929, the economy enjoyed a short high before nearly crashing[clarification needed] after Black Tuesday.

Austria

Austria lies between latitudes 46° and 49° N, and longitudes 9° and 18° E. It can be divided into five areas, the biggest being the Eastern Alps, which constitute 62% of the nation's total area.

Austria

Although Austria is cold in the winter (−10 to 0 °C), summer temperatures can be relatively high, with average temperatures in the mid-20s and a highest temperature of 40.5 °C (105 °F) in August 2013.

Vienna

Spring is variable and autumn cool, with possible snowfalls already in November.

Vienna

This law of neutrality, passed in late October 1955 (and not the State Treaty itself), ensured that modern Austria would align with neither NATO nor the Soviet bloc, and is considered one of the reasons for Austria's delayed entry into the European Union in 1995.


Since the mid 1970s, global temperatures have been warming at around 0.2 degrees Celsius per decade.

Global warming

Global warming

Multiple independently produced instrumental datasets confirm that the 2009–2018 decade was 0.93 ± 0.07 °C warmer than the pre-industrial baseline (1850–1900).

Global warming

Currently, surface temperatures are rising by about 0.2 °C per decade.

Global warming

Limiting new black carbon deposits in the Arctic could reduce global warming by 0.2 °C by 2050.

Instrumental temperature record

For 1979 to 2012, the linear warming trend for combined land and sea temperatures has been 0.155 °C (0.122 to 0.188 °C) per decade, according to AR5.


However, weather imposes its own dramatic ups and downs over the long term trend.

Tropical cyclone

All these effects can combine to produce a dramatic drop in sea surface temperature over a large area in just a few days.

Tropical cyclone

Kerry Emanuel stated, "Records of hurricane activity worldwide show an upswing of both the maximum wind speed in and the duration of hurricanes.

Weather

Surface temperature differences in turn cause pressure differences.

Weather

In some situations, the temperature actually increases with height.

Weather

Aside from climatic changes that have caused the gradual drift of populations (for example the desertification of the Middle East, and the formation of land bridges during glacial periods), extreme weather events have caused smaller scale population movements and intruded directly in historical events.


We expect to see record cold temperatures even during global warming.

Global cooling

"Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end, to be followed by a long period of considerably colder temperatures leading into the next glacial age some 20,000 years from now."

Global warming

Global warming is the long-term rise in the average temperature of the Earth's climate system.

Global warming

It is expected that most ecosystems will be affected by higher atmospheric CO2 levels and higher global temperatures.

Global warming

Global warming

This is much colder than the conditions that actually exist at the Earth's surface (the global mean surface temperature is about 14 °C).


Nevertheless over the last decade, daily record high temperatures occurred twice as often as record lows.

Atlanta

Lows at or below freezing can be expected 40 nights annually, but extended stretches with daily high temperatures below 40 °F (4 °C) are very rare, with a recent exception in January 2014.

Córdoba, Argentina

The record low temperature for Córdoba is −8.3 °C (17.1 °F).

Córdoba, Argentina

It is not unusual to see temperatures drop 20 °C (36 °F) from one day to another, or to have frost following extreme heat.

Istanbul

During these summer months, high temperatures average around 29 °C (84 °F) and rainfall is uncommon; there are only about fifteen days with measurable precipitation between June and August.

Tucson, Arizona

There is an average of 145.0 days annually with highs of 90 °F (32 °C) or higher and an average of 16.9 days with lows reaching or below the freezing mark.


"The 30 major droughts of the 20th century were likely natural in all respects; and, hence, they are "indicative of what could also happen in the future," as Narisma

Drought

Australia could experience more severe droughts and they could become more frequent in the future, a government-commissioned report said on July 6, 2008.

Effects of global warming

Some evidence suggests that droughts have been occurring more frequently because of global warming and they are expected to become more frequent and intense in Africa, southern Europe, the Middle East, most of the Americas, Australia, and Southeast Asia.

Illinois

"The Longest Running Title Droughts in Sports".

Sahel drought

Originally it was believed that the drought in the Sahel primarily was caused by humans over-using natural resources in the region through overgrazing, deforestation and poor land management.

United States

Increased variability and intensity of rainfall as a result of climate change is expected to produce both more severe droughts and flooding, with potentially serious consequences for water supply and for pollution from combined sewer overflows.


Everybody knows that the Pacific island of Tuvalu is sinking. ...

Tuvalu

Coordinates: 8°31′15″S 179°11′55″E / 8.52083°S 179.19861°E / -8.52083; 179.19861 Tuvalu (/tuːˈvɑːluː/ too-VAH-loo) (formerly known as the Ellice Islands), is a country in Polynesia, located in the Pacific Ocean, situated in Oceania and about midway between Hawaii and Australia.

Tuvalu

"A rising tide: Planning the future of a sinking island".

Tuvalu

"'Sinking' Pacific nation is getting bigger, showing islands are geologically dynamic: study | The Japan Times".

Tuvalu

"Coral islands defy sea-level rise over the past century: Records from a central Pacific atoll".

Tuvalu

Spanish discoveries in the Central Pacific.


Around 1990 it became obvious the local tide-gauge did not agree - there was no evidence of 'sinking.'

Sinking of MV Sewol

As of 17 April 2014, the ROK Coast Guard concluded that an "unreasonably sudden turn" to starboard, made between 8:48 and 8:49 a.m. (KST), caused the cargo to shift to port, which in turn caused the ship to list and to eventually become unmanageable for the crew.

Sinking of the RMS Lusitania

Although he might have achieved 21 knots and had given orders to raise steam ready to do so, he was also under orders to time his arrival at Liverpool for high tide so that the ship would not have to wait to enter port.

Sinking of the RMS Lusitania

The three had agreed that the Admiralty warning of "submarine activity 20 miles (32 km) south of Coningbeg" effectively overrode other Admiralty advice to keep to 'mid channel', which was precisely where the submarine had been reported.

Sinking of the RMS Titanic

Now, without warning she seemed to start forward, moving forward and into the water at an angle of about fifteen degrees.

Sinking of the RMS Titanic

He also stated that "I believe it must have been in places, not a continuous rip", but that the different openings must have extended along an area of around 300 feet, to account for the flooding in several compartments.


What they find is sea level rise has been steadily accelerating over the past century.

Sea level rise

More precise data gathered from satellite radar measurements reveal an accelerating rise of 7.5 cm (3.0 in) from 1993 to 2017, which is a trend of roughly 30 cm (12 in) per century.

Sea level rise

"Antarctica ice melt has accelerated by 280% in the last 4 decades".

Sea level rise

Climate scientists expect the rate to further accelerate during the 21st century.

Sea level rise

However scientists have found that ice is being lost, and at an accelerating rate.

Sea level rise

A 2018 systematic review study estimated that ice loss across the entire continent was 43 gigatons (Gt) per year on average during the period from 1992 to 2002, but has accelerated to an average of 220 Gt per year during the five years from 2012 to 2017.


A paper by Ross McKitrick, an economics professor at the  University of Guelph, and Patrick Michaels, an environmental studies  professor at the University of Virginia, concludes that half of the  global warming trend from 1980 to 2002 is caused by Urban Heat Island.

Hockey stick controversy

McIntyre agreed, and made contact with University of Guelph economics professor Ross McKitrick, a senior fellow of the Fraser Institute which opposed the Kyoto treaty, and co-author of Taken By Storm: The Troubled Science, Policy and Politics of Global Warming.

Patrick Michaels

A 2002 article published in the journal Climate Research by Michaels and three other scholars has predicted "a warming range of 1.3–3.0°C, with a central value of 1.9°C" over the 1990 to 2100 period, although he remarked that the "temperature range and central values determined in our study may be too great."

Patrick Michaels

Until 2007 he was research professor of environmental sciences at the University of Virginia, where he had worked from 1980.

Ross McKitrick

McKitrick has authored works about environmental economics and climate change issues, including co-authoring the book Taken by Storm: The Troubled Science, Policy and Politics of Global Warming, published in 2002.

Urban heat island

For example, Ross McKitrick and Patrick J. Michaels conducted a statistical study of surface-temperature data regressed against socioeconomic indicators, and concluded that about half of the observed warming trend (for 1979–2002) could be accounted for by the residual UHI effects in the corrected temperature data set they studied—which had already been processed to remove the (modeled) UHI contribution.


While urban areas are undoubtedly warmer than surrounding rural areas, this has had little to no impact on warming trends.

Urban heat island

An urban heat island (UHI) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities.

Urban heat island

On the other hand, one 1999 comparison between urban and rural areas proposed that urban heat island effects have little influence on global mean temperature trends.

Urban heat island

Surfaces in the urban areas tend to warm faster than those of the surrounding rural areas.

Urbanization

As a result, cities are often 1 to 3 °C (1.8 to 5.4 °F) warmer than surrounding landscapes.

Urbanization

For North America and Europe, such practice could reduce earth warming trends.


While the Medieval Warm Period saw unusually warm temperatures in some regions, globally the planet was cooler than current conditions.

Medieval Warm Period

Global temperature records taken from ice cores, tree rings, and lake deposits, have shown that the Earth may have been slightly cooler globally (by 0.03 °C) than in the early and mid-20th century.

Medieval Warm Period

Their reconstruction of the pattern is characterised by warmth over large part of North Atlantic, Southern Greenland, the Eurasian Arctic, and parts of North America which appears to substantially exceed that of the late 20th century (1961–1990) baseline and is comparable or exceeds that of the past decade or two in some regions.

Medieval Warm Period

Certain regions, such as central Eurasia, northwestern North America, and (with less confidence) parts of the South Atlantic, exhibit anomalous coolness.

Medieval Warm Period

study found warmth exceeding 1961–1990 levels in Southern Greenland and parts of North America during the Medieval Climate Anomaly (defined in the study from 950 to 1250) with warmth in some regions exceeding temperatures of the 1990–2010 period.

Medieval Warm Period

They also found that the warming during the 10–14th centuries in some regions might be comparable in magnitude to the warming of the last few decades of the 20th century, which was unprecedented within the past 500 years.


Now scientists are telling us that Mars is experiencing its own planetary warming: Martian warming.

Extraterrestrial atmosphere

"Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says".

Mars ocean hypothesis

As Tharsis volcanoes erupted they added huge amounts of gases into the atmosphere that created a global warming, thereby allowing liquid water to exist.

Mars

Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water.

Mars

They tend to occur when Mars is closest to the Sun, and have been shown to increase the global temperature.

Martian

They invade Earth because Mars is dying, and they need a warmer planet to live.


Martian climate is primarily driven by dust and albedo and there is little empirical evidence that Mars is showing long term warming.

Climate of Mars

Precession in the alignment of the obliquity and eccentricity lead to global warming and cooling ('great' summers and winters) with a period of 170,000 years.

Climate of Mars

Current research suggests that Mars is in a warm interglacial period which has lasted more than 100,000 years.

Climate of Mars

Geomorphic observations of both landscape erosion rates and Martian valley networks also strongly imply warmer, wetter conditions on Noachian-era Mars (earlier than about four billion years ago).

Mars

The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure, and the low thermal inertia of Martian soil.

Mars

Their low albedo and carbonaceous chondrite composition have been regarded as similar to asteroids, supporting the capture theory.


"In 2007, the Northern Hemisphere reached a record low in ice coverage and the Northwest Passage was opened.

Climate change in the Arctic

The 2007 melt season let to a minimum 39% below the 1979–2000 average, and for the first time in human memory, the fabled Northwest Passage opened completely.

Northwest Passage

On August 21, 2007, the Northwest Passage became open to ships without the need of an icebreaker.

Northwest Passage

The Northwest Passage opened again on August 25, 2008.

Northwest Passage

On September 14, 2007, the European Space Agency stated that ice loss that year had opened up the historically impassable passage, setting a new low of ice cover as seen in satellite measurements which went back to 1978.

Northwest Passage

The extreme loss in 2007 rendered the passage "fully navigable".


What you were not told was that the data that triggered this record is only available back to the late 1970s.

Criticism of NASCAR

The Car of Tomorrow was first tested in December 2005, and was first revealed to the public in 2006, with numerous safety improvements being touted.

D. B. Cooper

In late 2007, the FBI announced that a partial DNA profile had been obtained from three organic samples found on Cooper's clip-on tie in 2001, though they later acknowledged that there is no evidence that the hijacker was the source of the sample material.

Roswell UFO incident

Podesta stated, "It is time for the government to declassify records that are more than 25 years old and to provide scientists with data that will assist in determining the true nature of the phenomena."

Steele dossier

The Inspector General investigation by Michael E. Horowitz, published December 9, 2019, expressed doubts about the dossier's reliability and sources: The FBI concluded, among other things, that although consistent with known efforts by Russia to interfere in the 2016 U.S. elections, much of the material in the Steele election reports, including allegations about Donald Trump and members of the Trump campaign relied upon in the Carter Page FISA applications, could not be corroborated; that certain allegations were inaccurate or inconsistent with information gathered by the Crossfire Hurricane team; and that the limited information that was corroborated related to time, location, and title information, much of which was publicly available.

Steele dossier

The FBI Operation Crossfire Hurricane investigation into Russian interference, which started on July 31, 2016, was not triggered by the dossier, but the dossier is still the subject of the Russia investigation origins counter-narrative, a conspiracy theory pushed by Trump and Fox News.


We know the Northwest Passage had been open before."

Northwest Passage

The only usable route linking the entrances of Lancaster Sound and Dolphin and Union Strait was discovered by John Rae in 1854.

Northwest Passage

Northwest Passage

Northwest Passage

An ice-bound northern route was discovered in 1850 by the Irish explorer Robert McClure; it was through a more southerly opening in an area explored by the Scotsman John Rae in 1854 that Norwegian Roald Amundsen made the first complete passage in 1903–1906.

Northwest Passage

In 1602, George Weymouth became the first European to explore what would later be called Hudson Strait when he sailed Discovery 300 nautical miles (560 km) into the Strait.


Arctic sea ice has been retreating over the past 30 years.

Arctic

Due to the poleward migration of the planet's isotherms (about 56 km (35 mi) per decade during the past 30 years as a consequence of global warming), the Arctic region (as defined by tree line and temperature) is currently shrinking.

Global warming

Global warming has led to decades of shrinking and thinning of the Arctic sea ice, making it vulnerable to atmospheric anomalies.

Global warming

"What drove the dramatic arctic sea ice retreat during summer 2007?".

Sea ice

A composite record of Arctic ice demonstrates that the floes' retreat began around 1900, experiencing more rapid melting beginning within the past 50 years.

Sea level rise

"Antarctica ice melt has accelerated by 280% in the last 4 decades".


"While major green house gas  H2O substantially warms the Earth, minor green house gases such as CO2  have little effect....

Earth

Consequently, summers are 2.3 °C (4 °F) warmer in the Northern Hemisphere than in the Southern Hemisphere under similar conditions.

Global warming

Increased concentrations of gases such as CO 2 (~20%), ozone and N 2O are external forcing on the other hand.

Global warming

She found moist air warmed more than dry air, and CO 2 warmed most, so she concluded higher levels of this in the past would have increased temperatures: Huddleston 2019.

Greenhouse gas

The surprising effect of this is that the global warming potential of CO is three times that of CO 2.

Greenhouse gas

"Rapid atmospheric CO 2 changes associated with the 8,200-years-B.P.


Satellite measurements of infrared spectra over the past 40 years observe less energy escaping to space at the wavelengths associated with CO2.

European Southern Observatory

Cosmic-temperature measurements The VLT has detected, for the first time, carbon-monoxide molecules in a galaxy located almost 11 billion light-years away.

Infrared

The LWIR (8–15 μm) region is especially useful since some radiation at these wavelengths can escape into space through the atmosphere.

Satellite temperature measurements

The three channels use the same frequency but different carbon dioxide cell pressure, the corresponding weighting functions peaks at 29 km for channel 1, 37 km for channel 2 and 45 km for channel 3.

Satellite temperature measurements

The process of deriving trends from SSUs measurement has proved particularly difficult because of satellites drift, inter-calibration between different satellite with scant overlap and gas leak in the instrument carbon dioxide pressure cell, furthermore since the radiances measured by SSUs are due to emission by carbon dioxide the weighting functions move to higher altitudes as the carbon dioxide concentration in the stratosphere increase.

Satellite temperature measurements

They measure radiances in various wavelength bands.


Surface measurements find more downward infrared radiation warming the planet's surface.

Cloud

Most of the sunlight that reaches the ground is absorbed, warming the surface, which emits radiation upward at longer, infrared, wavelengths.

Cloud

The water reacts by radiating, also in the infrared, both upward and downward, and the downward longwave radiation results in increased warming at the surface.

Earth

Energy from the Sun heats this layer, and the surface below, causing expansion of the air.

Global warming

The warmed surface emits infrared radiation, but the atmosphere is relatively opaque to infrared and slows the emission of energy, warming the planet.

Global warming

This heat, in the form of infrared radiation, gets absorbed and emitted by these gases in the atmosphere, thus warming the lower atmosphere and the surface.


This provides a direct, empirical causal link between CO2 and global warming.

Climate change (general concept)

During the glacial cycles, there was a high correlation between CO 2 concentrations and temperatures.

Correlation does not imply causation:102

Correlation does not imply causation

To establish a correlation as causal within physics, it is normally understood that the cause and the effect must connect through a local mechanism (cf.

Global warming

One potential source of abrupt climate change would be the rapid release of methane and carbon dioxide from permafrost, which would amplify global warming.

Global warming

Although there are a few areas of linkage, the relationship between the two is weak.

Global warming

Other scientists were initially sceptical and believed the greenhouse effect to be saturated so that adding more CO 2 would make no difference.


The amount of warming caused by the anthropogenic increase in atmospheric CO2 may be one of the most misunderstood subjects in climate science.

Carbon dioxide

"How do we know more CO2 is causing warming?".

Greenhouse effect

Their effects, together with those of other anthropogenic drivers, have been detected throughout the climate system and are extremely likely to have been the dominant cause of the observed warming since the mid-20th century'".

Greenhouse gas

It is likely that anthropogenic (i.e., human-induced) warming, such as that due to elevated greenhouse gas levels, has had a discernible influence on many physical and biological systems.

Greenhouse gas

The surprising effect of this is that the global warming potential of CO is three times that of CO 2.

Scientific consensus on climate change:136

Scientific consensus on climate change

Most of the climatic warming over the last 50 years is likely to have been caused by increased concentrations of greenhouse gases in the atmosphere.


Early estimates of ocean heat from the Argo showed a cooling bias due to pressure sensor issues.

Argo (oceanography)

In most cases probes drift at a depth of 1000 metres (the so-called parking depth) and, every 10 days, by changing their buoyancy, dive to a depth of 2000 metres and then move to the sea-surface, measuring conductivity and temperature profiles as well as pressure.

Argo (oceanography)

Such measurements are important for developing a comprehensive understanding of the ocean, such as trends in heat content.

Argo (oceanography)

David Morrison reports that "[b]oth of these data sets show clear signatures of heat deposition in the ocean, from the temperature changes in the top 2 km of water and from the expansion of the ocean water due to heating.

Ocean heat content

Ocean heat content can be estimated using temperature measurements obtained by a Nansen bottle, an ARGO float, or ocean acoustic tomography.

Shutdown of thermohaline circulation

Based on coupled Atmosphere-Ocean General Circulation Models from 2001, the THC tends to weaken somewhat rather than stop, and the warming effects outweigh the cooling, even over Europe.


In truth, the overwhelming majority of climate-research funding comes from the federal government and left-wing foundations.

American Legislative Exchange Council:251

American Legislative Exchange Council

Greenpeace claims that ALEC has received $525,858 from Koch foundations between 2005 and 2011.

Climate change denial

Over the last 14 years Willie Soon, a researcher at the Harvard-Smithsonian Centre for Astrophysics, received a total of $1.25m from Exxon Mobil, Southern Company, the American Petroleum Institute (API) and a foundation run by the ultra-conservative Koch brothers… the biggest single funder was Southern Company, one of the country's biggest electricity providers that relies heavily on coal.

Climate change denial

Between 2003 and 2013, the donor-advised funds Donors Trust and Donors Capital Fund, combined, were the largest funders, accounting for about one quarter of the total funds, and the American Enterprise Institute was the largest recipient, 16% of the total funds.

Global warming

Organizations such as the libertarian Competitive Enterprise Institute, as well as conservative commentators, have challenged IPCC climate change scenarios, funded scientists who disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls.

Ted Cruz

Proponents of the bill argued that it would provide steady funding to support research and restoration projects, funded primarily by dedicating 12.5% of revenues from offshore energy development, including oil, gas, and renewable energy, through offshore lease sales and production based royalty payments, distributed through a competitive grant program.


The CO2 that nature emits (from the ocean and vegetation) is balanced by natural absorptions (again by the ocean and vegetation).

Carbon dioxide in Earth's atmosphere

Most sources of CO 2 emissions are natural, and are balanced to various degrees by natural CO 2 sinks.

Carbon dioxide

Currently, about half of the carbon dioxide released from the burning of fossil fuels remains in the atmosphere and is not absorbed by vegetation and the oceans.

Carbon dioxide

Most of the CO 2 taken up by the ocean, which is about 30% of the total released into the atmosphere, forms carbonic acid in equilibrium with bicarbonate.

Carbon dioxide

During active photosynthesis, plants can absorb more carbon dioxide from the atmosphere than they release in respiration.

Carbon dioxide

Additionally, and crucially to life on earth, photosynthesis by phytoplankton consumes dissolved CO 2 in the upper ocean and thereby promotes the absorption of CO 2 from the atmosphere.


Therefore human emissions upset the natural balance, rising CO2 to levels not seen in at least 800,000 years.

Carbon dioxide in Earth's atmosphere:140

Carbon dioxide in Earth's atmosphere

While CO 2 absorption and release is always happening as a result of natural processes, the recent rise in CO 2 levels in the atmosphere is known to be mainly due to human (anthropogenic) activity.

Carbon dioxide

Human activities have caused CO 2 to increase above levels not seen in hundreds of thousands of years.

Carbon dioxide

The current concentration is about 0.04% (410 ppm) by volume, having risen from pre-industrial levels of 280 ppm.

Global warming

These levels are much higher than at any time during the last 800,000 years, the period for which reliable data have been collected from ice cores.

Greenhouse gas

The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to the lapse of formerly declining trends in carbon intensity of both developing and developed nations.


In fact, human emit 26 gigatonnes of CO2 per year while CO2 in the atmosphere is rising by only 15 gigatonnes per year - much of human CO2 emissions is being absorbed by natural sinks.

Carbon dioxide

Human activities emit about 29 billion tons of carbon dioxide per year, while volcanoes emit between 0.2 and 0.3 billion tons.

Carbon dioxide

The oceans act as an enormous carbon sink, and have taken up about a third of CO 2 emitted by human activity.

Carbon sink

Presently, oceans are CO2 sinks, and represent the largest active carbon sink on Earth, absorbing more than a quarter of the carbon dioxide that humans put into the air.

Greenhouse gas

In the modern era, emissions to the atmosphere from volcanoes are approximately 0.645 billion tonnes of CO 2 per year, whereas humans contribute 29 billion tonnes of CO 2 each year.

Greenhouse gas

This increase has occurred despite the uptake of more than half of the emissions by various natural "sinks" involved in the carbon cycle.


"Unquestionably, the U.N. Intergovernmental Panel on Climate Change (IPCC) was formed to build the scientific case for humanity being the primary cause of global warming.

Attribution of recent climate change

According to the Intergovernmental Panel on Climate Change (IPCC), it is "extremely likely" that human influence was the dominant cause of global warming between 1951 and 2010.

Intergovernmental Panel on Climate Change:0

The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations that is dedicated to providing the world with objective, scientific information relevant to understanding the scientific basis of the risk of human-induced climate change, its natural, political, and economic impacts and risks, and possible response options.

Intergovernmental Panel on Climate Change:127

Since the mid-20th century, most of the observed warming is "likely" (greater than 66% probability, based on expert judgement) due to human activities.

Intergovernmental Panel on Climate Change:345

"The work of the Intergovernmental Panel on Climate Change (IPCC) represents the consensus of the international scientific community on climate change science.

Scientific consensus on climate change:183

Scientific consensus on climate change

In it, the IUGG concurs with the "comprehensive and widely accepted and endorsed scientific assessments carried out by the Intergovernmental Panel on Climate Change and regional and national bodies, which have firmly established, on the basis of scientific evidence, that human activities are the primary cause of recent climate change".


The IPCC lead authors are experts in their field, instructed to fairly represent the full range of the up-to-date, peer-reviewed literature.

Intergovernmental Panel on Climate Change:108

The choice of authors aims for a range of views, expertise and geographical representation, ensuring representation of experts from developing and developed countries and countries with economies in transition.

Intergovernmental Panel on Climate Change:27

The IPCC was tasked with reviewing peer-reviewed scientific literature and other relevant publications to provide information on the state of knowledge about climate change.

Intergovernmental Panel on Climate Change:79

Lead authors of IPCC reports assess the available information about climate change based on published sources.

Rather, it assesses published literature, including peer-reviewed and non-peer-reviewed sources.

Intergovernmental Panel on Climate Change:80

According to IPCC guidelines, authors should give priority to peer-reviewed sources.


Comparisons to the most recent data consistently finds that climate change is occurring more rapidly and intensely than indicated by IPCC predictions.

IPCC Fourth Assessment Report

The report notes many observed changes in the Earth's climate including atmospheric composition, global average temperatures, ocean conditions, and other climate changes.

Intergovernmental Panel on Climate Change:113

They judge that global mean surface air temperature has increased by 0.3 to 0.6 °C over the last 100 years, broadly consistent with prediction of climate models, but also of the same magnitude as natural climate variability.

Intergovernmental Panel on Climate Change:128

Projections based on the Special Report on Emissions Scenarios suggest warming over the 21st century at a more rapid rate than that experienced for at least the last 10,000 years.

Scientific consensus on climate change:107

Scientific consensus on climate change

The statement references the IPCC's Fourth Assessment of 2007, and asserts that "climate change is happening even faster than previously estimated; global CO 2 emissions since 2000 have been higher than even the highest predictions, Arctic sea ice has been melting at rates much faster than predicted, and the rise in the sea level has become more rapid".

Scientific consensus on climate change:75

Scientific consensus on climate change

Some of the changes have been faster than previous assessments had suggested.


Increased CO2 makes more water vapor, a greenhouse gas which amplifies warming

Carbon dioxide

Increases in atmospheric concentrations of CO 2 and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century.

Global warming

At the end of an ice age, warming from increased CO 2 would increase the amount of water vapour, amplifying its effect in a feedback process.

Greenhouse gas

Water vapor responds to and amplifies effects of the other greenhouse gases.

Greenhouse gas

Because water vapor is a greenhouse gas, this results in further warming and so is a "positive feedback" that amplifies the original warming.

Polar amplification

That’s important because water vapor is a greenhouse gas just like carbon dioxide and methane.


The public understand it, in that if  you get a fall evening or spring evening and the sky is clear the heat  will escape and the temperature will drop and you get frost.

Passive solar building design

A design with too much equator-facing glass can result in excessive winter, spring, or fall day heating, uncomfortably bright living spaces at certain times of the year, and excessive heat transfer on winter nights and summer days.

Passive solar building design

This will then radiate heat into the building in the evening.

Precipitation

Those bands bring strong localized snowfall which can be understood as follows: Large water bodies such as lakes efficiently store heat that results in significant temperature differences (larger than 13 °C or 23 °F) between the water surface and the air above.

Precipitation

when it gets cold, Mars has precipitation which most likely takes the form of frost, rather than rain or snow.

Thunderstorm

As the water vapor condenses into liquid, latent heat is released, which warms the air, causing it to become less dense than the surrounding, drier air.


If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Atmosphere of Venus

The large amount of CO2 in the atmosphere together with water vapour and sulfur dioxide create a strong greenhouse effect, trapping solar energy and raising the surface temperature to around 740 K (467 °C), hotter than any other planet in the Solar System, even that of Mercury despite being located farther out from the Sun and receiving only 25% of the solar energy (per unit area) Mercury does.

Global warming

As water is a potent greenhouse gas, this further heats the climate: the water vapour feedback.

Global warming

If cloud cover increases, more sunlight will be reflected back into space, cooling the planet.

Urban heat island

Throughout the daytime, particularly when the skies are cloudless, urban surfaces are warmed by the absorption of solar radiation.

Water

Water vapor and carbon dioxide in the atmosphere provide a temperature buffer (greenhouse effect) which helps maintain a relatively steady surface temperature.


Water vapour is the most dominant greenhouse gas.

Attribution of recent climate change

Water vapor is the most abundant greenhouse gas and is the largest contributor to the natural greenhouse effect, despite having a short atmospheric lifetime (about 10 days).

Climate system

The dominant contributor to the greenhouse effect is water vapour (~50%), with clouds (~25%) and CO 2 (~20%) also playing an important role.

Climate system

Some trace gases in the atmosphere, such as water vapour and carbon dioxide, are the gases most important for the workings of the climate system, as they are greenhouse gases which allow visible light from the Sun to penetrate to the surface, but block some of the infra-red radiation the Earth's surface emits to balance the Sun's radiation.

Global warming

While water vapour (~50%) and clouds (~25%) are the biggest contributors to the greenhouse effect, they increase as a function of temperature and are therefore considered feedbacks.

Global warming

The largest human influence has been the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide.


“A leading Canadian authority on polar bears, Mitch Taylor, said: ‘We’re  seeing an increase in bears that’s really unprecedented, and in places  where we’re seeing a decrease in the population

Baffin Island

[citation needed] In 2012, a survey of caribou herds found that the local population was only about 5,000, a decrease of as much as 95% from the 1990s.

Polar bear

"Ask the experts: Are polar bear populations increasing?".

Polar bear

In two areas where harvest levels have been increased based on increased sightings, science-based studies have indicated declining populations, and a third area is considered data-deficient.

Polar bear

Warnings about the future of the polar bear are often contrasted with the fact that worldwide population estimates have increased over the past 50 years and are relatively stable today.

Polar bear

In Nunavut, some Inuit have reported increases in bear sightings around human settlements in recent years, leading to a belief that populations are increasing.


The costs of inaction far outweigh the costs of mitigation.

Climate change mitigation

By addressing climate change, we can avoid the costs associated with the effects of climate change.

Climate change mitigation

According to the Stern Review, inaction can be as high as the equivalent of losing at least 5% of global gross domestic product (GDP) each year, now and forever (upto 20% of the GDP or more when including a wider range of risks and impacts), whereas mitigating climate change will only cost about 2% of the GDP.

Mitigation (law)

Mitigation in law is the principle that a party who has suffered loss (from a tort or breach of contract) has to take reasonable action to minimize the amount of the loss suffered.

Risk management

Implementation follows all of the planned methods for mitigating the effect of the risks.

Stern Review

Cline noted that the Review's large cost-benefit ratio for mitigation policy allows room for these long-term costs to be reduced substantially but still support aggressive action to reduce emissions.


Economic assessments of proposed policy to put a price on carbon emissions are in widespread agreement that the net economic impact will be minor.

Carbon tax

Various studies in the 1990s, and an economic analysis by Statistics Norway, have estimated the effect of the CO2 tax to be a reduction of 2.5–11% of Norwegian emissions under a business-as-usual approach (i.e., the predicted emissions that would have occurred without the tax).

Carbon tax

An Economic Assessment of Policy Instruments for Combating Climate Change.

Climate change mitigation

This is considered as a particularly difficult policy proposal as the economic growth of developing countries are proportionally reflected in the growth of greenhouse emissions.

Emissions trading

They all put a price on pollution (for example, see carbon price), and so provide an economic incentive to reduce pollution beginning with the lowest-cost opportunities.

Stern Review

Economists have different views over the cost estimates of climate change mitigation given in the Review.


Climate economics research shows that in reality, we are harming the economy by failing to implement CO2 limits.

Carbon tax

Economists generally argue that carbon taxes are the most efficient and effective way to curb climate change, with the least adverse effects on the economy.

Carbon tax

There is overwhelming agreement among economists that carbon taxes are the most efficient and effective way to curb climate change, with the least adverse effects on the economy.

Climate change mitigation

The importance of change is illustrated by the fact that world economic energy efficiency is improving at only half the rate of world economic growth.

Emissions trading

In theory, a polluter's decisions should lead to an economically efficient allocation of reductions among polluters, and lower compliance costs for individual firms and for the economy overall, compared to command-and-control mechanisms.

Sustainable development

Therefore, solutions need to be found so that the economies of the world can continue to grow, but not at the expense of the public good.


The Greenland ice sheet is at least 400,000 years old and warming was not global when Europeans settled in Greeland 1,000 years ago

Climate change in the Arctic

The effects of global warming in the Arctic, or climate change in the Arctic include rising air and water temperatures, loss of sea ice, and melting of the Greenland ice sheet with a related cold temperature anomaly, observed since the 1970s.

Greenland ice sheet

Ice sheet models project that such a warming would initiate the long-term melting of the ice sheet, leading to a complete melting of the ice sheet (over centuries), resulting in a global sea level rise of about 7 metres (23 ft).

Greenland ice sheet

Between 2001 and 2005: Sermeq Kujalleq broke up, losing 93 square kilometres (36 sq mi) and raised awareness worldwide of glacial response to global climate change.

North America

The Pre-Columbian era ended in 1492, with the beginning of the transatlantic migrations—the arrival of European settlers during the Age of Discovery and the Early Modern period.

Sea level rise

This acceleration is due mostly to human-caused global warming, which is driving thermal expansion of seawater and the melting of land-based ice sheets and glaciers.


There may have been regions of Greenland that were 'greener' than today

Greenland ice sheet

It has been observed that there is more precipitation where it is warmer, up to 1.5 meters per year on the southeast flank, and less precipitation or none on the 25–80 percent (depending on the time of year) of the island that is cooler.

Greenland

"Is Iceland Really Green and Greenland Really Icy?"

Greenland

Interpretation of ice core and clam shell data suggests that between 800 and 1300, the regions around the fjords of southern Greenland experienced a relatively mild climate several degrees Celsius higher than usual in the North Atlantic, with trees and herbaceous plants growing, and livestock being farmed.

Reforestation

The Great Green Wall initiative is a pan-African proposal to "green" the continent from west to east in order to battle desertification.

Sahara

When the North African monsoon is at its strongest annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the "green Sahara".


Greenland on the whole is losing ice, as confirmed by multiple satellite and on the ground field measurements.

Greenland ice sheet

These measurements came from the US space agency's GRACE (Gravity Recovery and Climate Experiment) satellite, launched in 2002, as reported by BBC.

Greenland ice sheet

Using data from two ground-observing satellites, ICESAT and ASTER, a study published in Geophysical Research Letters (September 2008) shows that nearly 75 percent of the loss of Greenland's ice can be traced back to small coastal glaciers.

Greenland ice sheet

Play media Satellite measurements of Greenland's ice cover from 1979 to 2009 reveals a trend of increased melting.

Greenland

Findings show that Greenland has lost 3.8 trillion tonnes of ice since 1992, enough to raise sea levels by almost 11mm (1.06cm).

Ice sheet

The Greenland, and possibly the Antarctic, ice sheets have been losing mass recently, because losses by ablation including outlet glaciers exceed accumulation of snowfall.


(2005), where satellite altimetry  established that the mean thickness of the entire Greenland ice sheet  had increased at 2 inches per year – a total of almost 2 feet – in the  11 years 1993-2003.”

Greenland ice sheet

In 2005, this had increased to about 220 km3 or 52.8 cu mi a year due to rapid thinning near its coasts, while in 2006 it was estimated at 239 km3 (57.3 cu mi) per year.

Greenland ice sheet

Assessment of the data and techniques suggests a mass balance for the Greenland Ice Sheet ranging between growth of 25 Gt/yr and loss of 60 Gt/yr for 1961 to 2003, loss of 50 to 100 Gt/yr for 1993 to 2003 and loss at even higher rates between 2003 and 2005.

Greenland ice sheet

Until 2007, rate of decrease in ice sheet height in cm per year.

Greenland

Other research has shown that higher snowfalls from the North Atlantic oscillation caused the interior of the ice cap to thicken by an average of 6 cm or 2.36 in/y between 1994 and 2005.

Sea level rise

This network was used, in combination with satellite altimeter data, to establish that global mean sea-level rose 19.5 cm (7.7 in) between 1870 and 2004 at an average rate of about 1.44 mm/yr (1.7 mm/yr during the 20th century).


While the Greenland interior is in mass balance, the coastlines are losing ice.

Retreat of glaciers since 1850

Inland glaciers have had a generally negative mass balance, whereby during the 1990s, maritime glaciers showed a positive mass balance and advanced.

Sea level rise

"A tipping point in refreezing accelerates mass loss of Greenland's glaciers and ice caps".

Sea level rise

"Greenland's Coastal Ice Caps Have Melted Past The Point Of No Return".

Sea level rise

The additional snowfall causes increased ice flow of the ice sheet into the ocean, so that the mass gain due to snowfall is partially compensated.

Sea level rise

Methods agree that the Totten Glacier has lost ice in recent decades in response to ocean warming and possibly a reduction in local sea ice cover.


Overall Greenland is losing ice mass at an accelerating rate.

Climate change in the Arctic

The rate of the decline in entire Arctic ice coverage is accelerating.

Retreat of glaciers since 1850

"Sharply increased mass loss from glaciers and ice caps in theCanadian Arctic Archipelago".

Sea level rise

Average annual ice loss in Greenland more than doubled in the early 21st century compared to the 20th century.

Sea level rise

Sea level rise

A 2018 systematic review study estimated that ice loss across the entire continent was 43 gigatons (Gt) per year on average during the period from 1992 to 2002, but has accelerated to an average of 220 Gt per year during the five years from 2012 to 2017.


While there are direct ways in which CO2 is a pollutant (acidification of the ocean), its primary impact is its greenhouse warming effect.

Carbon dioxide

While transparent to visible light, carbon dioxide is a greenhouse gas, absorbing and emitting infrared radiation at its two infrared-active vibrational frequencies (see the section "Structure and bonding" above).

Carbon dioxide

Increases in atmospheric concentrations of CO 2 and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century.

Carbon dioxide

Carbon dioxide is of greatest concern because it exerts a larger overall warming influence than all of these other gases combined and because it has a long atmospheric lifetime (hundreds to thousands of years).

Carbon dioxide

Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.

Pollution

The emission of greenhouse gases leads to global warming which affects ecosystems in many ways.


While the greenhouse effect is a natural occurence, too much warming has severe negative impacts on agriculture, health and environment.

Effects of global warming

The effects of global warming or climate damage include far-reaching and long-lasting changes to the natural environment, to ecosystems and human societies caused directly or indirectly by human emissions of greenhouse gases.

Effects of global warming

The impact on the environment, ecosystems, the animal kingdom, society and humanity depends on how much more the Earth warms.

Global warming

Generally, impacts on public health will be more negative than positive.

Global warming

Impacts include the direct effects of extreme weather, leading to injury and loss of life; and indirect effects, such as undernutrition brought on by crop failures.

Greenhouse gas

Future warming is projected to have a range of impacts, including sea level rise, increased frequencies and severities of some extreme weather events, loss of biodiversity, and regional changes in agricultural productivity.


'To suddenly label CO2 as a "pollutant" is a disservice to a gas that has played an enormous role in the development and sustainability of all life on this wonderful Earth.

Climate change mitigation

As is stated in Article 2 of the Convention, this requires that greenhouse gas (GHG) concentrations are stabilized in the atmosphere at a level where ecosystems can adapt naturally to climate change, food production is not threatened, and economic development can proceed in a sustainable fashion.

Emissions trading

Emissions trading (also known as cap and trade) is a market-based approach to controlling pollution by providing economic incentives for achieving reductions in the emissions of pollutants.

Sustainability

On the other hand, an extensive historical analysis of technological efficiency improvements has conclusively shown that improvements in the efficiency of the use of energy and materials were almost always outpaced by economic growth, in large part because of the rebound effect (conservation) or Jevons Paradox resulting in a net increase in resource use and associated pollution.

Sustainable energy

In its book, the Commission described four key elements of sustainability with respect to energy: the ability to increase the supply of energy to meet growing human needs, energy efficiency and conservation, public health and safety, and "protection of the biosphere and prevention of more localized forms of pollution."

Urbanization

Urbanization creates enormous social, economic and environmental changes, which provide an opportunity for sustainability with the "potential to use resources more efficiently, to create more sustainable land use and to protect the biodiversity of natural ecosystems."


Mother Earth has clearly ruled that CO2 is not a pollutant.'

Earth in science fiction

Its soil is utterly barren and its atmosphere is a fog of pollution.

Earth in science fiction

By the time of Resurrection, which is set in the 24th century, Earth as a whole is considered to be an unpleasant, polluted planet that even hardened mercenaries prefer to avoid.

Earth

There is a scientific consensus linking human activities to global warming due to industrial carbon dioxide emissions.

Mother goddess

Her work in this field has been questioned.

Mother goddess


Although it has some very important and beneficial effects, CO2 meets the legal and encyclopedic definitions of a "pollutant", and human CO2 emissions pose a threat to public health and welfare.

Climate change and agriculture

More favourable effects on yield tend to depend to a large extent on realization of the potentially beneficial effects of carbon dioxide on crop growth and increase of efficiency in water use.

Emissions trading

On April 17, 2009, the Environmental Protection Agency (EPA) formally announced that it had found that greenhouse gas (GHG) poses a threat to public health and the environment (EPA 2009a).

Ocean acidification

Although the natural absorption of CO 2 by the world's oceans helps mitigate the climatic effects of anthropogenic emissions of CO 2, it is believed that the resulting decrease in pH will have negative consequences, primarily for oceanic calcifying organisms.

Scientific consensus on climate change:651

Scientific consensus on climate change

It is anticipated that continuing changes to the climate will have serious negative impacts on public, animal and ecosystem health due to extreme weather events, changing disease transmission dynamics, emerging and re-emerging diseases, and alterations to habitat and ecological systems that are essential to wildlife conservation.

Scientific consensus on climate change:688

Scientific consensus on climate change

American Public Health Association Policy Statement Addressing the Urgent Threat of Global Climate Change to Public Health and the Environment, 2007, archived from the original on 2009-12-31 "The long-term threat of global climate change to global health is extremely serious and the fourth IPCC report and other scientific literature demonstrate convincingly that anthropogenic GHG emissions are primarily responsible for this threat….US policy makers should immediately take necessary steps to reduce US emissions of GHGs, including carbon dioxide, to avert dangerous climate change."


This growth stimulation occurs because CO2 is one of the two raw materials (the other being water) that are required for photosynthesis.

Carbon dioxide

Plants require carbon dioxide to conduct photosynthesis.

Carbon dioxide

Photosynthesis uses carbon dioxide and water to produce sugars from which other organic compounds can be constructed, and oxygen is produced as a by-product.

Carbon dioxide

Phototrophs use the products of their photosynthesis as internal food sources and as raw material for the biosynthesis of more complex organic molecules, such as polysaccharides, nucleic acids and proteins.

Carnivorous plant

The energy is used to reduce carbon dioxide from the air with electrons from water to make sugars (and other biomass) and a waste product, oxygen, in the process of photosynthesis.

Photosynthesis

Photosynthetic organisms are photoautotrophs, which means that they are able to synthesize food directly from carbon dioxide and water using energy from light.


Less energy is escaping to space: Carbon dioxide (CO2) acts like a blanket; adding more CO2 makes the 'blanket' thicker, and humans are adding more CO2 all the time.

Carbon dioxide in Earth's atmosphere

The increased radiative forcing due to increased CO2 in the Earth's atmosphere is based on the physical properties of CO2 and the non-saturated absorption windows where CO2 absorbs outgoing long-wave energy.

Carbon dioxide

Increases in atmospheric concentrations of CO 2 and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century.

Climate change mitigation

These include carbon dioxide (chemical formula: CO 2), methane (CH 4), nitrous oxide (N 2O), and a group of gases referred to as halocarbons.

Climate change mitigation

The reason for this is that human activities are adding CO2 to the atmosphere faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a complete explanation).

Climate change mitigation

Examples of mitigation include reducing energy demand by increasing energy efficiency, phasing out fossil fuels by switching to low-carbon energy sources, and removing carbon dioxide from Earth's atmosphere.


"There is no actual evidence that carbon dioxide emissions are causing global warming.

Climate change denial

There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gases is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate.

Global warming

CO2 emissions are continuing to rise due to the burning of fossil fuels and land-use change.

Global warming

In the scientific literature, there is an overwhelming consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases.

Global warming

"How the oceans absorb carbon dioxide is critical for predicting climate change".

Greenhouse gas

Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming, and give some indication of which countries have contributed most to human-induced climate change.


Note that computer models are just concatenations of calculations you could do on a hand-held calculator, so they are theoretical and cannot be part of any evidence."

Computer science

In 1937, one hundred years after Babbage's impossible dream, Howard Aiken convinced IBM, which was making all kinds of punched card equipment and was also in the calculator business to develop his giant programmable calculator, the ASCC/Harvard Mark I, based on Babbage's Analytical Engine, which itself used cards and a central computing unit.

Computer science

Peter Denning's working group argued that they are theory, abstraction (modeling), and design.

Computer science

In an effort to answer the first question, computability theory examines which computational problems are solvable on various theoretical models of computation.

Computer

This usage of the term referred to a human computer, a person who carried out calculations or computations.

Mathematics

When reconsidering data from experiments and samples or when analyzing data from observational studies, statisticians "make sense of the data" using the art of modelling and the theory of inference – with model selection and estimation; the estimated models and consequential predictions should be tested on new data.


Satellite and surface measurements find less energy is escaping to space at CO2 absorption wavelengths.

Carbon dioxide in Earth's atmosphere

CO 2 absorbs and emits infrared radiation at wavelengths of 4.26 µm (asymmetric stretching vibrational mode) and 14.99 µm (bending vibrational mode) and consequently is a greenhouse gas that plays a significant role in influencing Earth's surface temperature through the greenhouse effect.

Global warming potential

The radiative forcing capacity (RF) is the amount of energy per unit area, per unit time, absorbed by the greenhouse gas, that would otherwise be lost to space.

Greenhouse gas

Greenhouse gases are those that absorb and emit infrared radiation in the wavelength range emitted by Earth.

Greenhouse gas

The peak of the thermal IR emission from Earth's surface is very close to a strong vibrational absorption band of CO 2 (wavelength 15 microns, or wavenumber 667 cm−1).

Greenhouse gas

On the other hand, the single CO vibrational band only absorbs IR at much shorter wavelengths (4.7 microns, or 2145 cm−1), where the emission of radiant energy from Earth's surface is at least a factor of ten lower.


Ocean and surface temperature measurements find the planet continues to accumulate heat.

Earth

Because much of the heat is provided by radioactive decay, scientists postulate that early in Earth's history, before isotopes with short half-lives were depleted, Earth's heat production was much higher.

Earth

This last phenomenon is known as the greenhouse effect: trace molecules within the atmosphere serve to capture thermal energy emitted from the ground, thereby raising the average temperature.

Earth

Energy from the Sun heats this layer, and the surface below, causing expansion of the air.

Global warming

Throughout this period ocean heat storage continued to progress steadily upwards, and in subsequent years surface temperatures have spiked upwards.

Global warming

Greenhouse gases trap heat radiating from the Earth to space.


Mars, Triton, Pluto and Jupiter all show global warming, pointing to the Sun as the dominating influence in determining climate throughout the solar system."

Global warming

It is a major aspect of climate change and has been demonstrated by direct temperature measurements and by measurements of various effects of the warming.

Global warming

Another line of evidence for the warming not being due to the Sun is how temperature changes differ at different levels in the Earth's atmosphere.

Global warming

The largest human influence has been the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide.

Global warming

As the Sun is the Earth's primary energy source, changes in incoming sunlight directly affect the climate system.

Triton (moon)

As Neptune orbits the Sun, Triton's polar regions take turns facing the Sun, resulting in seasonal changes as one pole, then the other, moves into the sunlight.


The sun has shown no long term trend since 1950 and in fact has shown a slight cooling trend in recent decades.

Climate change (general concept)

Climate change is a long-term, sustained trend of change in climate.

Global warming

Since 1950, the number of cold days and nights have decreased, and the number of warm days and night have increased.

Little Ice Age

Orbital forcing from cycles in the earth's orbit around the sun has, for the past 2,000 years, caused a long-term northern hemisphere cooling trend that continued through the Middle Ages and the Little Ice Age.

Quaternary glaciation

Based on orbital models, the cooling trend initiated about 6,000 years ago will continue for another 23,000 years.

Solar activity and climate

In the three decades following 1978, the combination of solar and volcanic activity is estimated to have had a slight cooling influence.


As of today,JAXA shows that we have more ice than any time on this date for the past 8 years of Aqua satellite measurement for this AMSRE dataset."

Aqua (satellite)

Aqua carries six instruments for studies of water on the Earth's surface and in the atmosphere, of which four are still operating: Advanced Microwave Scanning Radiometer-EOS (AMSR-E) — measures cloud properties, sea surface temperature, near-surface wind speed, radiative energy flux, surface water, ice and snow.

Aqua (satellite)

Cooler A telemetry became frozen on March 24, 2014, but this had no impact on science gathering.

JAXA

Starting from 1979 with Hakucho (CORSA-b), for nearly two decades Japan had achieved continuous observation with its Hinotori, Tenma, Ginga and ASCA (ASTRO-A through D) x-ray observation satellites.

JAXA

However, due to various reasons,[specify] both satellites had a much shorter than expected life term.

Moon

Using the mapper's reflectance spectra, indirect lighting of areas in shadow confirmed water ice within 20° latitude of both poles in 2018.


Arctic sea ice has been steadily thinning, even in the last few years while the surface ice (eg - sea ice extent) increased slightly.

Arctic Ocean

The mean extent of the ice has been decreasing since 1980 from the average winter value of 15,600,000 km2 (6,023,200 sq mi) at a rate of 3% per decade.

Arctic Ocean

The Arctic ice pack is thinning, and a seasonal hole in the ozone layer frequently occurs.

Arctic Ocean

Nevertheless, as all the explorers who travelled closer and closer to the pole reported, the polar ice cap is quite thick, and persists year-round.

Arctic sea ice decline

A 2018 study of the thickness of sea ice found a decrease of 66% or 2.0 m over the last six decades and a shift from permanent ice to largely seasonal ice cover.

Global warming

Global warming has led to decades of shrinking and thinning of the Arctic sea ice, making it vulnerable to atmospheric anomalies.


Consequently, the total amount of Arctic sea ice in 2008 and 2009 are the lowest on record.

Arctic sea ice decline

The previous record of the lowest area of the Arctic Ocean covered by ice in 2012 saw a low of 1.58 million square miles (4.09 million square kilometers).

Arctic

The Arctic is affected by current global warming, leading to Arctic sea ice shrinkage, diminished ice in the Greenland ice sheet, and Arctic methane release as the permafrost thaws.

Arctic

The effects of global warming in the Arctic include rising temperatures, loss of sea ice, and melting of the Greenland ice sheet.

Climate change in the Arctic

The Arctic sea ice September minimum extent (i.e., area with at least 15% sea ice coverage) reached new record lows in 2002, 2005, 2007, and 2012.

Climate change in the Arctic

From 2008 to 2011, Arctic sea ice minimum extent was higher than 2007, but it did not return to the levels of previous years.


"Twentieth century global warming did not start until  1910.

20th century

The average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880; Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20 °C per decade.

20th century

Increasing awareness of global warming began in the 1980s, commencing decades of social and political debate.

Global warming

In 1896, he published the first climate model of its kind, showing that halving of CO 2 could have produced the drop in temperature initiating the ice age.

Global warming

From 1938 Guy Stewart Callendar published evidence that climate was warming and CO 2 levels increasing, but his calculations met the same objections.

Global warming

Temperatures rose by 0.0 °C–0.2 °C from 1720–1800 to 1850–1900 (Hawkins et al., 2017).


By that time CO2 emissions had already risen from the expanded use  of coal that had powered the industrial revolution, and emissions only  increased slowly from 3.5gigatonnes in 1910 to under 4gigatonnes by the  end of the Second World War.

Carbon dioxide in Earth's atmosphere:149

Carbon dioxide in Earth's atmosphere

In 2010, 9.14 gigatonnes of carbon (GtC, equivalent to 33.5 gigatonnes of CO 2 or about 4.3 ppm in Earth's atmosphere) were released from fossil fuels and cement production worldwide, compared to 6.15 GtC in 1990.

Carbon dioxide in Earth's atmosphere

Global annual mean CO 2 concentration has increased by more than 45% since the start of the Industrial Revolution, from 280 ppm during the 10,000 years up to the mid-18th century to 415 ppm as of May 2019.

Carbon dioxide

Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.

Fossil fuel

The widescale use of fossil fuels, coal at first and petroleum later, to fire steam engines enabled the Industrial Revolution.

Greenhouse gas

Human activities since the beginning of the Industrial Revolution (around 1750) have produced a 45% increase in the atmospheric concentration of carbon dioxide, from 280 ppm in 1750 to 415 ppm in 2019.


It was the post war  industrialization that caused the rapid rise in global CO2 emissions,  but by 1945 when this began, the Earth was already in a cooling phase  that started around 1942 and continued until 1975.

20th century

Carbon dioxide

Greenhouse gas

Between 1970 and 2004, global growth in annual CO 2 emissions was driven by North America, Asia, and the Middle East.

Greenhouse gas

The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to the lapse of formerly declining trends in carbon intensity of both developing and developed nations.

Ice age

An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers.


With 32 years of  rapidly increasing global temperatures and only a minor increase in  global CO2 emissions, followed by 33 years of slowly cooling global  temperatures with rapid increases in global CO2 emissions, it was  deceitful for the IPCC to make any claim that CO2 emissions were  primarily responsible for observed 20th century global warming."

Since the mid-20th century, most of the observed warming is "likely" (greater than 66% probability, based on expert judgement) due to human activities.

Intergovernmental Panel on Climate Change:358

"The IPCC Third Assessment Report'] conclusion that most of the observed warming of the last 50 years is likely to have been due to the increase in greenhouse gas concentrations accurately reflects the current thinking of the scientific community on this issue".

Scientific consensus on climate change:150

Scientific consensus on climate change

Human-caused increases in greenhouse gases are responsible for most of the observed global average surface warming of roughly 0.8 °C (1.5 °F) over the past 140 years.

Scientific consensus on climate change:459

Scientific consensus on climate change

The Intergovernmental Panel on Climate Change said the likelihood was 90 percent to 99 percent that emissions of heat-trapping greenhouse gases like carbon dioxide, spewed from tailpipes and smokestacks, were the dominant cause of the observed warming of the last 50 years.

Scientific consensus on climate change:69

Scientific consensus on climate change

The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases.


Even during a period of long term warming, there are short periods of cooling due to climate variability.

El Niño–Southern Oscillation

El Niño–Southern Oscillation (ENSO) is an irregularly periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics.

El Niño–Southern Oscillation

El Niño events cause short-term (approximately 1 year in length) spikes in global average surface temperature while La Niña events cause short term cooling.

Eocene

This warming is short lived, as benthic oxygen isotope records indicate a return to cooling at ~40 million years ago.

Little Ice Age

Orbital forcing from cycles in the earth's orbit around the sun has, for the past 2,000 years, caused a long-term northern hemisphere cooling trend that continued through the Middle Ages and the Little Ice Age.

Quaternary glaciation

Before the current ice age, which began 2 to 3 Ma, Earth's climate was typically mild and uniform for long periods of time.


Short term cooling over the last few years is largely due to a strong La Nina phase in the Pacific Ocean and a prolonged solar minimum.

El Niño

The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean.

El Niño–Southern Oscillation

El Niño–Southern Oscillation

An especially strong Walker circulation causes La Niña, resulting in cooler ocean temperatures in the central and eastern tropical Pacific Ocean due to increased upwelling.

La Niña

During a period of La Niña, the sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3 to 5°C (5.4 to 9°F).

La Niña

La Niña is the positive and cold phase of the El Niño–Southern Oscillation, and is associated with cooler-than-average sea surface temperatures in the central and eastern tropical Pacific Ocean.


The sun was warming up then, but the sun hasn’t been warming since 1970.

Sun

At the photosphere, the temperature has dropped to 5,700 K and the density to only 0.2 g/m3 (about 1/6,000 the density of air at sea level).

Sun

As one fragment of the cloud collapsed it also began to rotate because of conservation of angular momentum and heat up with the increasing pressure.

Sun

The Sun is gradually becoming hotter during its time on the main sequence, because the helium atoms in the core occupy less volume than the hydrogen atoms that were fused.

SUPPORTS NOT_ENOUGH_INFO REFUTES REFUTES SUPPORTS

Sun

However, the geological record demonstrates that Earth has remained at a fairly constant temperature throughout its history, and that the young Earth was somewhat warmer than it is today.

Sun

By contrast, the Sun's surface temperature is approximately 5,800 K. Recent analysis of SOHO mission data favors a faster rotation rate in the core than in the radiative zone above.