When life is considered, ocean acidification is often found to be a non-problem, or even a benefit.

Ocean acidification

Aside from the slowing and/or reversing of calcification, organisms may suffer other adverse effects, either indirectly through negative impacts on food resources, or directly as reproductive or physiological effects.

Ocean acidification

While the full implications of elevated CO2 on marine ecosystems are still being documented, there is a substantial body of research showing that a combination of ocean acidification and elevated ocean temperature, driven mainly by CO2 and other greenhouse gas emissions, have a compounded effect on marine life and the ocean environment.

Ocean acidification

For example, in regards to safety, the report found a "[high] potential for undesirable ecological side effects", and that ocean fertilization "may increase anoxic regions of ocean ('dead zones')".

Ocean acidification

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

Ocean acidification

Increasing acidity is thought to have a range of potentially harmful consequences for marine organisms such as depressing metabolic rates and immune responses in some organisms and causing coral bleaching.


Air pollution

Air pollution

Emissions from these sources can cause respiratory disease, childhood asthma, cancer, and other health problems.

Air pollution

Increased levels of fine particles in the air are linked to health hazards such as heart disease, altered lung function and lung cancer.

Hazard

Health hazards Hazards affecting the health of exposed persons, usually having an acute or chronic illness as the consequence.

Pollution

Short of survival, human concerns include the range from quality of life to health hazards.


The rate of global sea level rise on average has fallen by 40% the last century.

Global warming

Between 1993 and 2017, the global mean sea level rose on average by 3.1 ± 0.3 mm per year, with an acceleration detected as well.

Global warming

Over the 21st century, the IPCC projects that in a very high emissions scenario the sea level could rise by 61–110 cm.

Global warming

Sea level rise will continue over many centuries.

Global warming

rising sea levels, shrinking Arctic sea ice).

Sea level

For at least the last 100 years, sea level has been rising at an average rate of about 1.8 mm (0.07 in) per year.


Snowfall is increasing in the fall and winter in the Northern Hemisphere and North America with many records being set.

2014–15 North American winter

Many records for snowfall and temperature were broken, many for the month of February, with every state east of the Mississippi River being colder than average, some for the entire winter.

2014–15 North American winter

Snowflakes fell on 19 out of 28 days in the Boston, Massachusetts area, setting records in numerous locations with depths up to over 36.0 inches (91 cm) deep in certain places.

Cold wave

Seattle recorded its snowiest winter on record with 67.5 inches (171 cm) for the season at Sea-Tac Airport.

Cold wave

Snowfall records were confirmed all over the Midwest and the Northeast, especially around the Great Lakes.

Snow

The following are world records regarding snowfall and snowflakes: Highest seasonal total snowfall – The world record for the highest seasonal total snowfall was measured in the United States at Mt.


The increase in damage in recent years is due to population growth in vulnerable areas and poor forest management.

Agriculture

The development of agriculture enabled the human population to grow many times larger than could be sustained by hunting and gathering.

Burkina Faso

Burkina Faso's rapidly growing population (around 3.6% annually) continues to put a strain on the country's resources and infrastructure, which can further limit accessibility to food.

Effects of global warming

Socio-economic factors have contributed to the observed trend of global losses, e.g., population growth, increased wealth.

Forestry in India

India defines forest management as one where the economic needs of local communities are not ignored, rather forests are sustained while meeting nation's economic needs and local issues through scientific forestry.

Vietnam

The average growth rate of the urban population has recently increased which is attributed mainly to migration and rapid urbanisation.


Droughts and floods have not changed since weve been using fossil fuels

Drought

According to the WWF, the combination of climate change and deforestation increases the drying effect of dead trees that fuels forest fires.

Effects of global warming

However, other research suggests that there has been little change in drought over the past 60 years.

Effects of global warming

Due to deforestation the rainforest is losing this ability, exacerbated by climate change which brings more frequent droughts to the area.

Effects of global warming

There may have been changes in other climate extremes (e.g., floods, droughts and tropical cyclones) but these changes are more difficult to identify.

History of the world

The increased demands are contributing to increased environmental degradation and to global warming, with resultant intensification of tropical cyclones, floods, droughts, forest fires, and incidence of hyperthermia deaths.


Heat waves have been decreasing since the 1930s in the U.S. and globally.

Heat wave

The famous heat wave events of Chicago in 1995 and the European heat wave of 2003 regions will experience longer, more frequent and more intense heat waves in the latter 21st century.

Heat wave

June 2019 was the hottest month on record worldwide, the effects of this were especially prominent in Europe.

Heat wave

This was used to estimate heat waves occurrence at the global scale from 1901 to 2010, finding a substantial and sharp increase in the amount of affected areas in the last two decades.

Heat wave

's Heat Wave Duration Index is that a heat wave occurs when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C (9 °F), the normal period being 1961–1990.

List of heat waves

Massive heat waves across North America were persistent in the 1930s, many mid-Atlantic/Ohio valley states recorded their highest temperatures during July 1934.


Climategate CRU emails suggest conspiracy

Climatic Research Unit email controversy:236

The CRU emails do not show either that the science is flawed or that the scientific process has been compromised.

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:64

An editorial in Nature stated that "A fair reading of the e-mails reveals nothing to support the denialists' conspiracy theories."

Conspiracy theory

"Analysis of the appeal of conspiracy theories with suggestions for more accurate ad hoc internet reporting of them".

Phil Jones (climatologist)

"'Conspiracy theories finally laid to rest' by report on leaked climate change emails".


Hurricanes aren't linked to global warming

Atlantic hurricane

Effects of global warming on human health:395

Health concerns around the world can be linked to floods.

Global warming

"Q&A: How is Arctic warming linked to the 'polar vortex' and other extreme weather?".

Hurricane Sandy

Global warming contributes 0.6°C to this.

Tropical cyclone

"African Dust Linked To Hurricane Strength".


Extreme weather isn't caused by global warming

Extreme weather

Extreme Weather Prompts Unprecedented Global Warming Alert.

Extreme weather

Scientists attribute extreme weather to man-made climate change.

Extreme weather

Researchers have for the first time attributed recent floods, droughts and heat waves, to human-induced climate change.

Global warming

Climate change is more accurate scientifically to describe the various effects of greenhouse gases on the world because it includes extreme weather, storms and changes in rainfall patterns, ocean acidification and sea level.".

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.


Arctic ice pack

The Arctic ice pack undergoes a regular seasonal cycle in which ice melts in spring and summer, reaches a minimum around mid-September, then increases during fall and winter.

Arctic ice pack

As well as the regular seasonal cycle there has been an underlying trend of declining sea ice in the Arctic in recent decades.

Arctic oscillation

The Arctic oscillation (AO) or Northern Annular Mode/Northern Hemisphere Annular Mode (NAM) is a weather phenomenon at the Arctic poles north of 20 degrees latitude.

Arctic

"Arctic cut-off high drives the poleward shift of a new Greenland melting record".

Arctic

The melting of the ice is making the Northwest Passage, the shipping routes through the northernmost latitudes, more navigable, raising the possibility that the Arctic region will become a prime trade route.


Water vapor is the most powerful greenhouse gas

Atmospheric methane

Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth's atmosphere.

Greenhouse gas

The oxidation of methane can produce both ozone and water; and is a major source of water vapor in the normally dry stratosphere.

Natural gas

Natural gas is thus a more potent greenhouse gas than carbon dioxide due to the greater global-warming potential of methane.

Water vapor

Water vapor is the most potent greenhouse gas owing to the presence of the hydroxyl bond which strongly absorbs in the infra-red region of the light spectrum.

Water vapor

Being a component of Earth's hydrosphere and hydrologic cycle, it is particularly abundant in Earth's atmosphere where it is also a potent greenhouse gas along with other gases such as carbon dioxide and methane.


Polar bear

For decades, large-scale hunting raised international concern for the future of the species, but populations rebounded after controls and quotas began to take effect.

Polar bear

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

Polar bear

The numbers taken grew rapidly in the 1960s, peaking around 1968 with a global total of 1,250 bears that year.

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

Of the 19 recognized polar bear subpopulations, one is in decline, two are increasing, seven are stable, and nine have insufficient data, as of 2017.


Through its impacts on the climate, CO2 presents a danger to public health and welfare, and thus qualifies as an air pollutant

Air pollution

An air pollutant is a material in the air that can have adverse effects on humans and the ecosystem.

Effects of global warming

Climate change will impact agriculture and food production around the world due to the effects of elevated CO2 in the atmosphere, higher temperatures, altered precipitation and transpiration regimes, increased frequency of extreme events, and modified weed, pest, and pathogen pressure.

Effects of global warming

Tipping points are "perhaps the most ‘dangerous’ aspect of future climate changes", leading to irreversible impacts on society.

Human impact on the environment

This creates air pollution, including nitrous oxides and particulates, and is a significant contributor to global warming through emission of carbon dioxide, for which transport is the fastest-growing emission sector.

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.


Adventure Time

The first game based on the series, Adventure Time: Hey Ice King!

Antarctica

This means that it is a very cold continent where water is mostly in the form of ice.

Captain America: The First Avenger

... We have to deal with much the same way that Captain America, when thawed from the Arctic ice, entered a world that he didn't recognize," similar to the way Stan Lee and Jack Kirby reintroduced the character in the 1960s.

Hip hop music

Hip hop's "golden age" (or "golden era") is a name given to a period in mainstream hip hop, produced between the mid-1980s and the early 1990s, which is characterized by its diversity, quality, innovation and influence.

Toy Story

"'Toy Story' Takes the Ice to the Blue Line and Beyond!".


2nd law of thermodynamics contradicts greenhouse theory

Second law of thermodynamics

The theory of classical or equilibrium thermodynamics is idealized.

Second law of thermodynamics

This does not conflict with notions that have been observed of the fundamental laws of physics, namely CPT symmetry, since the second law applies statistically, it is hypothesized, on time-asymmetric boundary conditions.

Second law of thermodynamics

Loschmidt's paradox, also known as the reversibility paradox, is the objection that it should not be possible to deduce an irreversible process from the time-symmetric dynamics that describe the microscopic evolution of a macroscopic system.

Second law of thermodynamics

The recurrence theorem may be perceived as apparently contradicting the second law of thermodynamics.

Second law of thermodynamics


IPCC were wrong about Himalayan glaciers

Ganges

In 2007, the Intergovernmental Panel on Climate Change (IPCC), in its Fourth Report, stated that the Himalayan glaciers which feed the river, were at risk of melting by 2035.

Ganges

In its statement, the IPCC stands by its general findings relating to the Himalayan glaciers being at risk from global warming (with consequent risks to water flow into the Gangetic basin).

IPCC Fourth Assessment Report

The report has also been criticized for inclusion of an erroneous date for the projected demise of the Himalayan glaciers.

Intergovernmental Panel on Climate Change:183

Two errors include the melting of Himalayan glaciers (see later section), and Dutch land area that is below sea level.

Intergovernmental Panel on Climate Change:265

Former IPCC chairman Robert Watson said, regarding the Himalayan glaciers estimation, "The mistakes all appear to have gone in the direction of making it seem like climate change is more serious by overstating the impact.


Cloud feedback

Changes in subtropical humidity could provide a negative feedback that decreases the amount of water vapor which in turn would act to mediate global climate transitions.

Cloud feedback

The albedo of increased cloudiness cools the climate, resulting in a negative feedback; while the reflection of infrared radiation by clouds warms the climate, resulting in a positive feedback.

Cloud

Broadly speaking, if clouds, especially low clouds, increase in a warmer climate, the resultant cooling effect leads to a negative feedback in climate response to increased greenhouse gases.

Cloud

But if low clouds decrease, or if high clouds increase, the feedback is positive.

Tropical cyclone

This effect results in a negative feedback process that can inhibit further development or lead to weakening.


IPCC were wrong about Amazon rainforests

Amazon basin

Most of the basin is covered by the Amazon Rainforest, also known as Amazonia.

Amazon rainforest

It concluded that the forest is on the brink of[vague] being turned into savanna or desert, with catastrophic consequences for the world's climate.

Amazon rainforest

Research suggests that upon reaching about 20–25% (hence 3–8% more), the tipping point to flip it into a non-forest ecosystems – degraded savannah – (in eastern, southern and central Amazonia) will be reached.

Deforestation

IPCC NASA Data Shows Deforestation Affects Climate In The Amazon.

Tropical rainforest

"Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils".


Greenland ice sheet

On balance, the IPCC estimates −44 ± 53 Gt/yr, which means that the ice sheet may currently be melting.

Greenland ice sheet

"Greenland Hits 97 Percent Meltdown in July".

Greenland ice sheet

"Images Show Breakup of Two of Greenland's Largest Glaciers, Predict Disintegration in Near Future".

Greenland ice sheet

James E. Hansen has argued that multiple positive feedbacks could lead to nonlinear ice sheet disintegration much faster than claimed by the IPCC.

Greenland

If the Greenland ice sheet were to melt away completely, the world's sea level would rise by more than 7 m (23 ft).


Excess CO2 from human emissions has a long residence time of over 100 years

Greenhouse gas

The average residence time of a water molecule in the atmosphere is only about nine days, compared to years or centuries for other greenhouse gases such as CH 4 and CO 2.

Greenhouse gas

Aside from water vapor, which has a residence time of about nine days, major greenhouse gases are well mixed and take many years to leave the atmosphere.

Greenhouse gas

Carbon dioxide has a variable atmospheric lifetime, and cannot be specified precisely.

Greenhouse gas

The atmospheric lifetime of CO 2 is estimated of the order of 30–95 years.

Greenhouse gas

Although more than half of the CO 2 emitted is removed from the atmosphere within a century, some fraction (about 20%) of emitted CO 2 remains in the atmosphere for many thousands of years.


Scientists tried to 'hide the decline' in global temperature

Climatic Research Unit documents

The email was widely misquoted as a "trick" to "hide the decline" as though it referred to a decline in measured global temperatures, but this was obviously untrue as when the email was written temperatures were far from declining: 1998 had been the warmest year recorded.

Climatic Research Unit documents

On 9 December 2009 Sarah Palin said the truncated phrase showed a "highly politicised scientific circle" had "manipulated data to 'hide the decline' in global temperatures", and at the 2009 United Nations Climate Change Conference in Copenhagen, senator Senator Jim Inhofe quoted Jones, and said "Of course he means hide the decline in temperatures".

Climatic Research Unit documents

The phrase "hide the decline" referred specifically to the divergence problem in which some post 1960 tree ring proxy data indicates a decline while measured temperatures rise.

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.

Hockey stick controversy

Despite this and the fact that 1999 had just seen record breaking global temperatures, the email was widely misquoted as a "trick" to "hide the decline" as though it referred to a decline in measured global temperatures, an accusation made publicly by the politicians Sarah Palin and Jim Inhofe.


They changed the name from 'global warming' to 'climate change'

Global warming

"Reduction in surface climate change achieved by the 1987 Montreal Protocol".

Global warming

"Assessing dangerous climate change through an update of the Intergovernmental Panel on Climate Change (IPCC) 'reasons for concern'".

Global warming

"UK Parliament declares climate change emergency".

Global warming

Research in the 1950s suggested that temperatures were increasing, and a 1952 newspaper used the term "climate change".

Global warming

In technical sources, the term climate change is also used to refer to past and future climate changes that persist for and extended period of time, and includes regional changes as well as global change.


'Global warming' and 'climate change' mean different things and have both been used for decades.

Climate change (general concept)

Scientists have identified many episodes of climate change during Earth's geological history; more recently since the industrial revolution the climate has increasingly been affected by human activities driving global warming, and the terms are commonly used interchangeably in that context.

Global warming

Global warming and climate change are often used interchangeably.

Global warming

Global warming

Both the terms global warming and climate change were used only occasionally until 1975, when Wallace Smith Broecker published a scientific paper on the topic, "Climatic Change: Are We on the Brink of a Pronounced Global Warming?".

Global warming


Global warming

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

Global warming

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

IPCC Fourth Assessment Report

As global average temperature increase exceeds about 3.5°C, model projections suggest significant extinctions (40–70% of species assessed) around the globe.

IPCC Fourth Assessment Report

This range of values is not a projection of the temperature rise we will see in the 21st century, since the future change in carbon dioxide concentrations is unknown, and factors besides carbon dioxide concentrations affect temperature.

Richard Lindzen

The IPCC (2007) estimates that the expected rise in temperature due to a doubling of CO2 to be about 3 °C (5.4 °F), ± 1.5°.


Peer review

Richard Smith, MD, former editor of the British Medical Journal, has claimed that peer review is "ineffective, largely a lottery, anti-innovatory, slow, expensive, wasteful of scientific time, inefficient, easily abused, prone to bias, unable to detect fraud and irrelevant; Several studies have shown that peer review is biased against the provincial and those from low- and middle-income countries; Many journals take months and even years to publish and the process wastes researchers' time.

Peer review

Multiple examples across several areas of science find that scientists elevated the importance of peer review for research that was questionable or corrupted.

Peer review

At times, peer review has been exposed as a process that was orchestrated for a preconceived outcome.

Peer review

In 2010, the US Senate Finance Committee released a report that found this practice was widespread, that it corrupted the scientific literature and increased prescription rates.

Peer review

If anything, the current peer review process and academic system could penalize, or at least fail to incentivize, such integrity.


Global sea level data shows that sea level rise has been increasing since 1880 while future sea level rise predictions are based on  physics, not statistics.

Sea level rise

Using different satellites from 1992 to 2017 shows melt is increasing significantly over this period.

Sea level rise

For instance, Mercer published a study in 1978 predicting that anthropogenic carbon dioxide warming and its potential effects on climate in the 21st century could cause a sea level rise of around 5 metres (16 ft) from melting of the West Antarctic ice-sheet alone.

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).

Sea level rise

This is an important confirmation of climate change simulations which predicted that sea level rise would accelerate in response to global warming.

Sea level rise

As climate research into past and present sea levels leads to improved computer models, projections have consistently increased.


Humans are too insignificant to affect global climate

Climate system

Accumulation of heat-trapping greenhouse gases, mainly being emitted by people burning fossil fuels, is causing global warming.

Holocene extinction

In order to constitute the Holocene as an extinction event, scientists must determine exactly when anthropogenic greenhouse gas emissions began to measurably alter natural atmospheric levels on a global scale, and when these alterations caused changes to global climate.

Holocene extinction

The timing of South American megafaunal extinction appears to precede human arrival, although the possibility that human activity at the time impacted the global climate enough to cause such an extinction has been suggested.

Human impact on the environment

In the real world, consumption of fossil fuel resources leads to global warming and climate change.

Human

Currently, through land development, combustion of fossil fuels, and pollution, humans are thought to be the main contributor to global climate change.


Lindzen and Choi find low climate sensitivity

Global warming controversy

"SYR 2.3: Climate sensitivity and feedbacks".

Global warming controversy

"Heat Capacity, Time Constant and Sensitivity of Earth's Climate System" (PDF).

Iris hypothesis

"Missing iris effect as a possible cause of muted hydrological change and high climate sensitivity in models".

Richard Lindzen

This hypothesis suggests a negative feedback which would counter the effects of CO 2 warming by lowering the climate sensitivity.

Richard Lindzen

Lindzen has given estimates of the Earth's climate sensitivity to be 0.5 °C based on ERBE data.


Phil Jones says no global warming since 1995

Global warming

"Reduction in surface climate change achieved by the 1987 Montreal Protocol".

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 Framework Convention was agreed on in 1992, but global emissions have risen since then.

Global warming

Hockey stick controversy

He said there had probably been no global warming since the 1940s, and "Satellite data show no appreciable warming of the global atmosphere since 1979.


Infrared Iris will reduce global warming

Global dimming

However some research shows that black carbon will increase global warming, being second only to CO2.

Global dimming

Global dimming creates a cooling effect that reduces the global average temperature elevation of greenhouse gases on global warming by 0.3-0.7 degrees centigrade.

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

Global warming

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


Instrumental temperature record

Greenhouse gases trap outgoing radiation warming the atmosphere which in turn warms the land.

Sea level

Second, as ocean temperatures rise, the warmer water expands.

Sea surface temperature

Secondly, the satellite cannot look through clouds, creating a cool bias in satellite-derived SSTs within cloudy areas.

Urban heat island

Concerns have been raised about possible contribution from urban heat islands to global warming.

Urban heat island

While the "heat island" warming is an important local effect, there is no evidence that it biases trends in the homogenized historical temperature record.


Tree-rings diverge from temperature after 1960

Climate

For example, "a 3°C change in mean annual temperature corresponds to a shift in isotherms of approximately 300–400 km in latitude (in the temperate zone) or 500 m in elevation.

Climate

A microthermal climate is one of low annual mean temperatures, generally between 0 °C (32 °F) and 14 °C (57 °F) which experiences short summers and has a potential evaporation between 14 centimetres (5.5 in) and 43 centimetres (17 in).

Global temperature record

Recent evidence suggests that a sudden and short-lived climatic shift between 2200 and 2100 BCE occurred in the region between Tibet and Iceland, with some evidence suggesting a global change.

Sun

Earlier extended minima have been discovered through analysis of tree rings and appear to have coincided with lower-than-average global temperatures.

Temperature record of the past 1000 years:20

One such method, based on principles of dendroclimatology, uses the width and other characteristics of tree rings to infer temperature.


Over 31,000 scientists signed the OISM Petition Project

A Scientific Dissent from Darwinism

According to the National Science Foundation, there were approximately 955,300 biological scientists in the United States in 1999.

A Scientific Dissent from Darwinism

Critics have noted that of the 105 "scientists" listed on the original 2001 petition, fewer than 20% were biologists, with few of the remainder having the necessary expertise to contribute meaningfully to a discussion of the role of natural selection in evolution.

Art Robinson

The OISM website states that "several members of the Institute's staff are also well known for their work on the Petition Project", and that the petition has "more than 31,000" signatures by scientists.

Art Robinson

Robinson asserted in 2008 that the petition has over 31,000 signatories, with 9,000 of these holding a PhD degree.

Oregon Petition

As of 2013, the petition's website states, "The current list of 31,487 petition signers includes 9,029 PhD; 7,157 MS; 2,586 MD and DVM; and 12,715 BS or equivalent academic degrees.


Less than half of published scientists endorse global warming

An Inconvenient Truth

A 2004 survey, by Naomi Oreskes of 928 peer-reviewed scientific articles on global climate change published between 1993 and 2003.

Scientific consensus on climate change:10

Scientific consensus on climate change

Of these, 97% agree, explicitly or implicitly, that global warming is happening and is human-caused.

Scientific consensus on climate change:256

Scientific consensus on climate change

Various surveys have been conducted to evaluate scientific opinion on global warming.

Scientific consensus on climate change:294

Scientific consensus on climate change

Over 99.99% of climate scientists did not reject AGW in their peer-reviewed research.

Scientific consensus on climate change:837

Scientific consensus on climate change

Scientists Reach 100% Consensus on Anthropogenic Global Warming.


Plant stomata show higher and more variable CO2 levels

Photosynthesis

Plant species with the greatest photosynthetic rates and Kranz anatomy showed no apparent photorespiration, very low CO2 compensation point, high optimum temperature, high stomatal resistances and lower mesophyll resistances for gas diffusion and rates never saturated at full sun light.

Proxy (climate)

New approaches retrieve data such as CO 2 content of past atmospheres from fossil leaf stomata and isotope composition, measuring cellular CO2 concentrations.

Stoma

These studies imply the plants response to changing CO2 levels is largely controlled by genetics.

Stoma

Rates of leaf photosynthesis were shown to increase by 30–50% in C3 plants, and 10–25% in C4 under doubled CO2 levels.

Stoma

These scientific instruments are commonly used by plant physiologists to measure CO2 uptake and thus measure photosynthetic rate.


Freedom of Information (FOI) requests were ignored

Association of Chief Police Officers

As a private company, ACPO was not subject to freedom of information legislation.

Association of Chief Police Officers

From November 2011, however, FOI requests could be made to ACPO.

Climatic Research Unit email controversy:248

In two cases, the Information Commissioner's Office (ICO) issued decisions on appeals of Freedom of Information (FOI) requests which had been turned down by the university.

Climatic Research Unit email controversy:65

It said that emails showed harassment of researchers, with multiple Freedom of Information requests to the Climatic Research Unit, but release of information had been hampered by national government restrictions on releasing the meteorological data researchers had been using.

Julian Assange

la Repubblica said that its FOI requests had been hindered and delayed in all jurisdictions.


Tuvalu

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

Tuvalu

Tuvalu is also affected by perigean spring tide events which raise the sea level higher than a normal high tide.

Tuvalu

Tuvaluan leaders have been concerned about the effects of rising sea levels.

Tuvalu

Gradual sea-level rise also allows for coral polyp activity to increase the reefs.

Tuvalu

Mean sea-level rise is projected to continue (very high confidence).


Power station

This less valuable "spare" electricity comes from uncontrolled wind power and base load power plants such as coal, nuclear and geothermal, which still produce power at night even though demand is very low.

Renewable energy commercialization

Geothermal power plants can operate 24 hours per day, providing baseload capacity.

Renewable energy

EGS and HDR technologies, such as hydrothermal geothermal, are expected to be baseload resources which produce power 24 hours a day like a fossil plant.

Wind power

about 8% of total nameplate capacity) to be used as reliable, baseload electric power which can be relied on to handle peak loads, as long as minimum criteria are met for wind speed and turbine height.

Wind power

"Supplying Baseload Power and Reducing Transmission Requirements by Interconnecting Wind Farms" (PDF).


Satellite error inflated Great Lakes temperatures

Great Lakes Storm of 1913

The immense volume of water in the five Great Lakes holds heat that allows the lakes to remain relatively warm for much later into the year and postpones the Arctic spread in the region.

Great Lakes

"More recently, evaporation over lakes has steadily been increasing, largely due to increases in water surface temperature," Gronewold said.

Great Lakes

Dynamically updated data Surface temperatures Water levels Currents Ship locations Water levels since 1918

Lake Erie

Because it is the shallowest, it is also the warmest of the Great Lakes, and in 1999 this almost became a problem for two nuclear power plants which require cool lake water to keep their reactors cool.

Lake Superior


Soares finds lack of correlation between CO2 and temperature

Correlation does not imply causation

The two variables aren't related at all, but correlate by chance.

Cross-correlation

In time series analysis and statistics, the cross-correlation of a pair of random process is the correlation between values of the processes at different times, as a function of the two times.

Pearson correlation coefficient

In statistics, the Pearson correlation coefficient (PCC, pronounced /ˈpɪərsən/), also referred to as Pearson's r, the Pearson product-moment correlation coefficient (PPMCC) or the bivariate correlation, is a measure of the linear correlation between two variables X and Y.

Pearson correlation coefficient

According to the Cauchy–Schwarz inequality it has a value between +1 and −1, where 1 is total positive linear correlation, 0 is no linear correlation, and −1 is total negative linear correlation.

Pearson correlation coefficient

A value of 0 implies that there is no linear correlation between the variables.


97% consensus on human-caused global warming has been disproven

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.

Intergovernmental Panel on Climate Change:190

It is extremely likely (95-100% probability) that human influence was the dominant cause of global warming between 1951-2010.

Scientific consensus on climate change

Of these, 97% agree, explicitly or implicitly, that global warming is happening and is human-caused.

Scientific consensus on climate change:19

Scientific consensus on climate change

It is extremely likely (95–100% probability) that human influence was the dominant cause of global warming between 1951–2010.

Scientific consensus on climate change:266

Scientific consensus on climate change

97% of the scientists surveyed agreed that global temperatures had increased during the past 100 years; 84% said they personally believed human-induced warming was occurring, and 74% agreed that "currently available scientific evidence" substantiated its occurrence.


An exponential increase in CO2 will result in a linear increase in temperature

Creep (deformation)

Coble creep is still temperature dependent, as the temperature increases so does the grain boundary diffusion.

Soil respiration

Due to the increase in temperature of the soil, CO2 levels in our atmosphere increase, and as such the mean average temperature of the Earth is rising.

Soil respiration

As stated earlier, the CO2 released by soil respiration is a greenhouse gas that will continue to trap energy and increase the global mean temperature if concentrations continue to rise.

Soil respiration

Temperature will increase respiration exponentially to a maximum, at which point respiration will decrease to zero when enzymatic activity is interrupted.

Virial expansion

The third virial coefficient thus derived would increase monotonically as temperature is lowered from the critical point to the triple point.


Adapting to global warming is cheaper than preventing it

Climate change adaptation

"Geoengineering: How to Cool Earth--At a Price".

Climate change adaptation

Adaptation is especially important in developing countries since those countries are bearing the brunt of the effects of global warming.

Global warming

Successful adaptation is easier if there are substantial emission reductions.

Global warming

Adaptation is especially important in developing countries since they are predicted to bear the brunt of the effects of global warming.

Global warming

The capacity and potential for humans to adapt, called adaptive capacity, is unevenly distributed across different regions and populations, and developing countries generally have less capacity to adapt.


Venus doesn't have a runaway greenhouse effect

Greenhouse effect

The planet Venus experienced runaway greenhouse effect, resulting in an atmosphere which is 96% carbon dioxide, with surface atmospheric pressure roughly the same as found 900 m (3,000 ft) underwater on Earth.

Greenhouse effect

A runaway greenhouse effect involving carbon dioxide and water vapor has long ago been hypothesized to have occurred on Venus, this idea is still largely accepted[citation needed].

Terraforming of Venus

Venus receives about twice the sunlight that Earth does, which is thought to have contributed to its runaway greenhouse effect.

Venus

It may have had water oceans in the past, but these would have vaporized as the temperature rose due to a runaway greenhouse effect.

Venus

The CO 2-rich atmosphere generates the strongest greenhouse effect in the Solar System, creating surface temperatures of at least 735 K (462 °C; 864 °F).


Solar phenomena

Luminosity decreases caused by sunspots (generally < - 0.3%) are correlated with increases (generally < + 0.05%) caused both by faculae that are associated with active regions as well as the magnetically active 'bright network'.

Sun

At this point in the dynamo cycle, buoyant upwelling within the convective zone forces emergence of toroidal magnetic field through the photosphere, giving rise to pairs of sunspots, roughly aligned east–west and having footprints with opposite magnetic polarities.

Sun

Long-term secular change in sunspot number is thought, by some scientists, to be correlated with long-term change in solar irradiance, which, in turn, might influence Earth's long-term climate.

Sunspot

Sunspots number is correlated with the intensity of solar radiation over the period since 1979, when satellite measurements became available.

Sunspot

On longer time scales, such as the solar cycle, other magnetic phenomena (faculae and the chromospheric network) correlate with sunspot occurrence.


CO2 increase is natural, not human-caused

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.

Global warming

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs, and nitrous oxide.

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.

Sustainability

In 2007 climate scientists of the IPCC concluded that there was at least a 90% probability that atmospheric increase in CO2 was human-induced, mostly as a result of fossil fuel emissions but, to a lesser extent from changes in land use.


BP

It established an alternative and low carbon energy business in 2005, with plans to invest $8 billion over a 10-year period into renewable energy sources including solar, wind, and biofuels, and non-renewable sources including natural gas and hydrogen power.

Green-collar worker

Some 2.3 million people have found renewable energy jobs in recent years, and projected investments of $630 billion by 2030 would translate into at least 20 million additional jobs.

Renewable energy commercialization

A key benefit that this investment growth brings is a growth in jobs.

Renewable energy commercialization

Renewable power has been more effective in creating jobs than coal or oil in the United States.

Renewable energy

Globally there are an estimated 7.7 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer.


Carbon dioxide

Less energy reaches the upper atmosphere, which is therefore cooler because of this absorption.

Carbon dioxide

Occupational CO 2 exposure limits have been set in the United States at 0.5% (5000 ppm) for an eight-hour period.

Gaia hypothesis

As the temperature rises closer to the value the white daisies like, the white daisies outreproduce the black daisies, leading to a larger percentage of white surface, and more sunlight is reflected, reducing the heat input and eventually cooling the planet.

Global warming

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

Global warming

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


The Schmittner et al. study finds low probability of both very low and very high climate sensitivities, and its lower estimate (as compared to the IPCC) is based on a new temperature reconstruction of the Last Glacial Maximum that may or may not withstand the test of time.

Climate change feedback

This is the "likely" range (greater than 66% probability), based on the expert judgement of the IPCC's authors.

Climate sensitivity

For constant humidity they computed a climate sensitivity of 2.3 °C per doubling of CO2 (which they rounded to 2, the value most often quoted from their work, in the abstract of the paper).

Climate sensitivity

The IPCC Fifth Assessment Report reverted to the earlier range of 1.5 to 4.5 °C (2.7 to 8.1 °F) (high confidence) because some estimates using industrial-age data came out low.

IPCC Fifth Assessment Report

Compared to the previous report, the lower bounds for the sensitivity of the climate system to emissions were slightly lowered, though the projections for global mean temperature rise (compared to pre-industrial levels) by 2100 exceeded 1.5 °C in all scenarios.

Kyoto Protocol

The Intergovernmental Panel on Climate Change (IPCC, 2007) have produced a range of projections of what the future increase in global mean temperature might be.


Greenland has only lost a tiny fraction of its ice mass

Glacier

The ablation zone is the region where there is a net loss in glacier mass.

Greenland ice sheet

If iceberg calving has happened as an average, Greenland lost 294 Gt of its mass during 2007 (one km3 of ice weighs about 0.9 Gt).

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).

Greenland

"Greenland Glaciers Losing Ice Much Faster, Study Says".

Retreat of glaciers since 1850

Between then and 2010, the mountain lost 80 percent of its ice — two-thirds of which since another scientific expedition in the 1970s.


Global warming controversy

In fact, one site said that it was proven in 1996 that Santer had fraudulently altered the IPCC report.

Greenhouse gas

A Contribution of Working Groups I, II, and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).

Intergovernmental Panel on Climate Change:109

The IPCC First Assessment Report (FAR) was completed in 1990, and served as the basis of the UNFCCC.

Intergovernmental Panel on Climate Change:118

Climate Change 1995, the IPCC Second Assessment Report (SAR), was finished in 1996.

Intergovernmental Panel on Climate Change:74

The IPCC published its First Assessment Report (FAR) in 1990, a supplementary report in 1992, a Second Assessment Report (SAR) in 1995, a Third Assessment Report (TAR) in 2001, a Fourth Assessment Report (AR4) in 2007 and a Fifth Assessment Report (AR5) in 2014.


Philosophical skepticism

Philosophical skepticism (UK spelling: scepticism; from Greek σκέψις skepsis, "inquiry") is a philosophical school of thought that questions the possibility of certainty in knowledge.

Skepticism

Skepticism (American English) or scepticism (British English, Australian English, and Canadian English) is generally a questioning attitude or doubt towards one or more items of putative knowledge or belief or dogma.

Skepticism

In India the Ajñana school of philosophy espoused skepticism.

Skepticism

In this way, Hume embraced what he called a "mitigated" skepticism, while rejecting an "excessive" Pyrrhonian skepticism that he saw as both impractical and psychologically impossible.

Skepticism

In ordinary usage, skepticism (US) or scepticism (UK) (Greek: 'σκέπτομαι' skeptomai, to search, to think about or look for; see also spelling differences) can refer to: an attitude of doubt or a disposition to incredulity either in general or toward a particular object; the doctrine that true knowledge or some particular knowledge is uncertain; the method of suspended judgment, systematic doubt, or criticism that is characteristic of skeptics (Merriam–Webster).


IPCC graph showing accelerating trends is misleading

Intergovernmental Panel on Climate Change:220

A potentially important area for consideration is also the detection of trends in extreme events and the attribution of these trends to human influence.

Intergovernmental Panel on Climate Change:267

The IPCC needs to look at this trend in the errors and ask why it happened".

Intergovernmental Panel on Climate Change:277

These studies were widely presented as demonstrating that the current warming period is exceptional in comparison to temperatures between 1000 and 1900, and the MBH99 based graph featured in publicity.

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.

Temperature record of the past 1000 years:46

This was the basis of a "schematic diagram" featured in the IPCC First Assessment Report beside cautions that the medieval warming might not have been global.


Climate change isn't increasing extreme weather damage costs

Climate change in the United States

Human-induced climate change has, e.g., the potential to alter the prevalence and severity of extreme weathers such as heat waves, cold waves, storms, floods and droughts.

Effects of global warming

For example, developed countries will be negatively affected by increases in the severity and frequency of some extreme weather events, such as heat waves.

Effects of global warming

Global losses reveal rapidly rising costs due to extreme weather-related events since the 1970s.

Effects of global warming

For example, humans living on atoll islands face risks due to sea level rise, sea surface warming, and increased frequency and intensity of extreme weather events.

Heat wave

Global warming boosts the probability of extreme weather events, like heat waves, far more than it boosts more moderate events.


UAH atmospheric temperatures prove climate models and/or surface temperature data sets are wrong

John Christy

We have found that climate models and popular surface temperature data sets overstate the changes in the real atmosphere and that actual changes are not alarming."

Microwave Sounding Unit temperature measurements:111

Globally, most climate models used by the IPCC in preparation of their third assessment in 2007 show a slightly greater warming at the TLT level than at the surface (0.03 °C/decade difference) for 1979–1999 while the GISS trend is +0.161 °C/decade for 1979 to 2012, the lower troposphere trends calculated from satellite data by UAH and RSS are +0.130 °C/decade and +0.206 °C/decade.

Microwave Sounding Unit temperature measurements:53

The results are thus not precisely comparable to surface temperature models.

UAH satellite temperature dataset

In comparing these measurements to surface temperature models, it is important to note that values for the lower troposphere measurements taken by the MSU are a weighted average of temperatures over multiple altitudes (roughly 0 to 12 km), and not a surface temperature (as seen in figure above).

UAH satellite temperature dataset

The results are thus not precisely comparable to surface temperature records or models.


We didn't have global warming during the Industrial Revolution

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.

Global warming

Climate proxy records show that natural variations offset the early effects of the Industrial Revolution, so there was little net warming between the 18th century and the mid-19th century, when thermometer records began to provide global coverage.

Global warming

Before the Industrial Revolution, naturally occurring amounts of greenhouse gases caused the air near the surface to be warmer by about 33 °C (59 °F) than it would be in their absence.

Global warming

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs, and nitrous oxide.

Scientific consensus on climate change:713

Scientific consensus on climate change

Human activities resulting from the industrial revolution have changed the chemical composition of the atmosphere....Deforestation is now the second largest contributor to global warming, after the burning of fossil fuels.


Loehle and Scafetta find a 60 year cycle causing global warming

Global warming hiatus

A study published in January 2015 proposed that the hiatus resulted from a 60-year oscillatory pattern of natural variability ssociated with the AMO and PDO, interacting with a secular warming trend due mainly to human caused increases in greenhouse gas levels.

Global warming hiatus

The 60- to 80-year cycle of the atmospheric and oceanic variability over the North Atlantic was also linked to the hiatus by two studies published in 2013 and was used to infer the length of the hiatus.

Global warming

By itself, the climate system experiences various cycles which can last for years (such as the El Niño–Southern Oscillation) to decades or centuries.

Nicola Scafetta

In a 2011 article published in The Open Atmospheric Science Journal ecologist Craig Loehle of the National Council for Air and Stream Improvement (a forest industry institution) and Scafetta forecast that the world climate "may remain approximately steady until 2030-2040, and may at most warm 0.5-1.0°C by 2100 at the estimated 0.66°C/century anthropogenic warming rate".

Nicola Scafetta


Holocene extinction

One of the main theories to the extinction is climate change.

Little Ice Age

Past Climate Variability in South America and Surrounding Regions.

Little Ice Age

"Causes of Climate Change over the Past 1000 Years".

Paleolithic

This epoch experienced important geographic and climatic changes that affected human societies.

Quaternary extinction event

"The character of late-glacial and post-glacial climatic changes".


We have had ice ages and warmer periods when alligators were found in Spitzbergen.

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.

Ice age

Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet.

Ice age

The colder periods are called glacial periods, the warmer periods interglacials, such as the Eemian Stage.

Ice age

The current geological period, the Quaternary, which began about 2.6 million years ago and extends into the present, is marked by warm and cold episodes, cold phases called glacials (Quaternary ice age) lasting about 100,000 years, and which are then interrupted by the warmer interglacials which lasted about 10,000–15,000 years.

Miocene

Climates remained moderately warm, although the slow global cooling that eventually led to the Pleistocene glaciations continued.


Scientific analysis of past climates shows that greenhouse gasses, principally CO2, have controlled most ancient climate changes.

Climatology

Most climate models include the radiative effects of greenhouse gases such as carbon dioxide.

Eocene

Greenhouse gases, in particular carbon dioxide and methane, played a significant role during the Eocene in controlling the surface temperature.

Global warming

Scientists have determined that the major factors causing the current climate change are greenhouse gases, land use changes, and aerosols and soot.

Paleoclimatology

The opposite effect is volcanism, responsible for the natural greenhouse effect, by emitting CO2 into the atmosphere, thus affecting glaciation (Ice Age) cycles.

Paleoclimatology

Studies of past changes in the environment and biodiversity often reflect on the current situation, specifically the impact of climate on mass extinctions and biotic recovery and current global warming.


This makes it clear that this time around humans are the cause, mainly by our CO2 emissions.

Air pollution

Pollutants emitted into the atmosphere by human activity include: Carbon dioxide (CO 2) – Because of its role as a greenhouse gas it has been described as "the leading pollutant" and "the worst climate pollutant".

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

Global anthropogenic greenhouse gas emissions in 2010 were equivalent to 49 billion tonnes of carbon dioxide (using the most recent global warming potentials over 100 years from the AR5 report).

Scientific consensus on climate change:130

Scientific consensus on climate change

The introduction includes this statement: There is strong evidence that the warming of the Earth over the last half-century has been caused largely by human activity, such as the burning of fossil fuels and changes in land use, including agriculture and deforestation.

Scientific consensus on climate change:5

Scientific consensus on climate change

Human activities (primarily greenhouse gas emissions) are the primary cause.


The data suggests solar activity is influencing the global climate causing the world to get warmer."

21st century

Climate scientists have reached a consensus that the earth is undergoing significant anthropogenic (human-induced) global warming.

Climate

Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling.

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.

El Niño–Southern Oscillation

The studies of historical data show the recent El Niño variation is most likely linked to global warming.

Global warming


In the last 35 years of global warming, the sun has shown a slight cooling trend.

Global warming

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

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).

Global warming

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

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.


The consequences of climate change become increasingly bad after each additional degree of warming, with the consequences of 2°C being quite damaging and the consequences of 4°C being potentially catastrophic.

Climate change mitigation

For example, limiting global warming to 1.5 °C relative to pre-industrial levels reduces climate change damages more than a 2 °C limit.

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

It is a major aspect of climate change, and has been demonstrated by the instrumental temperature record which shows global warming of around 1 °C since the pre-industrial period, although the bulk of this (0.9°C) has occurred since 1970.

Effects of global warming

Researchers have warned that current economic modeling may seriously underestimate the impact of potentially catastrophic climate change and point to the need for new models that give a more accurate picture of potential damages.

Effects of global warming

For increases in global average temperature exceeding 1.5 to 2.5 °C (relative to global temperatures over the years 1980–1999) and in concomitant atmospheric CO 2 concentrations, projected changes in ecosystems will have predominantly negative consequences for biodiversity and ecosystems goods and services, e.g., water and food supply.


The Petition Project features over 31,000 scientists signing the petition stating "There is no convincing scientific evidence that human release of carbon dioxide will, in the forseeable future, cause catastrophic heating of the Earth's atmosphere ...".

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

In November 2017, a second warning to humanity signed by 15,364 scientists from 184 countries stated that "the current trajectory of potentially catastrophic climate change due to rising greenhouse gases from burning fossil fuels, deforestation, and agricultural production – particularly from farming ruminants for meat consumption" is "especially troubling".

Scientific consensus on climate change:175

Scientific consensus on climate change

Evidence from the geological record is consistent with the physics that shows that adding large amounts of carbon dioxide to the atmosphere warms the world and may lead to: higher sea levels and flooding of low-lying coasts; greatly changed patterns of rainfall; increased acidity of the oceans; and decreased oxygen levels in seawater.

Scientific consensus on climate change:543

Scientific consensus on climate change

7–10 "There is now convincing evidence that since the industrial revolution, human activities, resulting in increasing concentrations of greenhouse gases have become a major agent of climate change.

Scientific consensus on climate change:77

Scientific consensus on climate change

Human activities, primarily the burning of fossil fuels (coal, oil, and natural gas), and secondarily the clearing of land, have increased the concentration of carbon dioxide, methane, and other heat-trapping ("greenhouse") gases in the atmosphere...There is international scientific consensus that most of the warming observed over the last 50 years is attributable to human activities.


That humans are causing global warming is the position of the Academies of Science from 80 countries plus many scientific organizations that study climate science.

Global warming

There are more than two dozen scientific institutions that develop climate models.

Global warming

These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing.

Scientific consensus on climate change:144

Scientific consensus on climate change

International Council of Academies of Engineering and Technological Sciences (CAETS) in 2007, issued a Statement on Environment and Sustainable Growth: As reported by the Intergovernmental Panel on Climate Change (IPCC), most of the observed global warming since the mid-20th century is very likely due to human-produced emission of greenhouse gases and this warming will continue unabated if present anthropogenic emissions continue or, worse, expand without control.

Scientific consensus on climate change:171

Scientific consensus on climate change

The Geological Society of America (GSA) concurs with assessments by the National Academies of Science (2005), the National Research Council (2006), and the Intergovernmental Panel on Climate Change (IPCC, 2007) that global climate has warmed and that human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s.

Scientific consensus on climate change:89

Scientific consensus on climate change

Since 2001, 34 national science academies, three regional academies, and both the international InterAcademy Council and International Council of Academies of Engineering and Technological Sciences have made formal declarations confirming human induced global warming and urging nations to reduce emissions of greenhouse gases.


More specifically, around 95% of active climate researchers actively publishing climate papers endorse the consensus position.

Scientific consensus on climate change

Nearly all publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 3% of contrarian studies either cannot be replicated or contain errors.

Scientific consensus on climate change:282

Scientific consensus on climate change

76 out of 79 climatologists who "listed climate science as their area of expertise and who also have published more than 50% of their recent peer-reviewed papers on the subject of climate change" believed that mean global temperatures had risen compared to pre-1800s levels.

Scientific consensus on climate change:287

Scientific consensus on climate change

A 2010 paper in the Proceedings of the National Academy of Sciences of the United States (PNAS) reviewed publication and citation data for 1,372 climate researchers and drew the following two conclusions: (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC (Anthropogenic Climate Change) outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.

Scientific consensus on climate change:294

Scientific consensus on climate change

Over 99.99% of climate scientists did not reject AGW in their peer-reviewed research.

Scientific consensus on climate change:326

Scientific consensus on climate change


All the indicators show that global warming is still happening.

Global warming

Many regions have probably already seen increases in warm spells and heat waves, and it is virtually certain that these changes will continue over the 21st century.

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

Arctic temperatures have increased and are predicted to continue to increase during this century at over twice the rate of the rest of the world.

Global warming

The 10th Emissions Gap Report issued by the United Nations Environment Programme (UNEP) predicts that if emissions continue to increase at the same rate as they have in 2010–2020, global temperatures would rise by as much as 4° by 2100.

Global warming

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


"In fact global warming has stopped and a cooling is beginning.

Global warming

According to basic physical principles, the greenhouse effect produces warming of the lower atmosphere (the troposphere), but cooling of the upper atmosphere (the stratosphere).

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

This could trigger cooling in the North Atlantic, Europe, and North America.

Ice age

The reflection of energy into space resulted in a global cooling, triggering the Pleistocene Ice Age.

Nuclear winter

1883 eruption of Krakatoa, which caused approximately 1 kelvin of global cooling for 2 years due to sulfate emissions.


No climate model has predicted a cooling of the Earth – quite the  contrary.

Eocene

The models, while accurately predicting the tropics, tend to produce significantly cooler temperatures of up to 20 °C (36 °F) colder than the actual determined temperature at the poles.

Global warming

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

Ice age

Most contemporary scientists thought that the Earth had been gradually cooling down since its birth as a molten globe.

Nuclear winter

The severity of this cooling in Alan Robock's model suggests that the cumulative products of 100 of these firestorms could cool the global climate by approximately 1 °C (1.8 °F), largely eliminating the magnitude of anthropogenic global warming for the next roughly two or three years.

Nuclear winter

The smoke resulting would be largely opaque to solar radiation but transparent to infrared, thus cooling the Earth by blocking sunlight, but not creating warming by enhancing the greenhouse effect.


Empirical measurements of the Earth's heat content show the planet is still accumulating heat and global warming is still happening.

Earth

"Evidence is now 'unequivocal' that humans are causing global warming – UN report".

Earth

This is predicted to produce changes such as the melting of glaciers and ice sheets, more extreme temperature ranges, significant changes in weather and a global rise in average sea levels.

Global warming

Since the pre-industrial period, global average land temperatures have increased almost twice as fast as global average temperatures.

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).

Instrumental temperature record

The global average and combined land and ocean surface temperature, show a warming of 0.85 [0.65 to 1.06] °C, in the period 1880 to 2012, based on multiple independently produced datasets.


Surface temperatures can show short-term cooling when heat is exchanged between the atmosphere and the ocean, which has a much greater heat capacity than the air.

Convection

Longitudinal circulation, on the other hand, comes about because the ocean has a higher specific heat capacity than land (and also thermal conductivity, allowing the heat to penetrate further beneath the surface ) and thereby absorbs and releases more heat, but the temperature changes less than land.

Global warming

This is due to the larger heat capacity of oceans and because oceans lose more heat by evaporation.

Global warming

When soot is suspended in the atmosphere, it directly absorbs solar radiation, heating the atmosphere and cooling the surface.

Tropical cyclone

This cooling is primarily caused by wind-driven mixing of cold water from deeper in the ocean with the warm surface waters.

Tropical cyclone

latent heat) at the temperature of the warm ocean surface (during evaporation, the ocean cools and the air warms).


"[Models] are full of fudge factors that are fitted to the existing climate, so the models more or less agree with the observed data.

Astronomy

In the case of an inconsistency between the data and model's results, the general tendency is to try to make minimal modifications to the model so that it produces results that fit the data.

Mathematical model

As the purpose of modeling is to increase our understanding of the world, the validity of a model rests not only on its fit to empirical observations, but also on its ability to extrapolate to situations or data beyond those originally described in the model.

Models of scientific inquiry

The idea of 'too baroque' is connected to 'simplicity': "a theory jammed with fudge factors is not very elegant.

Models of scientific inquiry

A good theory: Is elegant (Formal elegance; no ad hoc modifications) Contains few arbitrary or adjustable elements (simplicity/parsimony) Agrees with and explains all existing observations (unificatory/explanatory power) Makes detailed predictions about future observations that can disprove or falsify the model if they are not borne out.

Scientific modelling

However, a fit to empirical data alone is not sufficient for a model to be accepted as valid.


While there are uncertainties with climate models, they successfully reproduce the past and have made predictions that have been subsequently confirmed by observations.

General circulation model

These models are the basis for model predictions of future climate, such as are discussed by the IPCC.

Hockey stick controversy

It broadly agreed with the basic findings of the original MBH studies which had subsequently been supported by other reconstructions and proxy records, while emphasising uncertainties over earlier periods.

Ozone depletion

Nevertheless, within three years most of the basic assumptions made by Rowland and Molina were confirmed by laboratory measurements and by direct observation in the stratosphere.

Science

Natural science is concerned with the description, prediction, and understanding of natural phenomena based on empirical evidence from observation and experimentation.

Science

This new explanation is used to make falsifiable predictions that are testable by experiment or observation.


The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers.

Climatology

Scientists use both direct and indirect observations of the climate, from Earth observing satellites and scientific instrumentation such as a global network of thermometers, to prehistoric ice extracted from glaciers.

Global warming

In areas with high soot production, such as rural India, as much as 50% of surface warming due to greenhouse gases may be masked by atmospheric brown clouds.

Urban heat island

For example, urban and rural trends are very similar.

Urban heat island

This was done by using satellite-based night-light detection of urban areas, and more thorough homogenisation of the time series (with corrections, for example, for the tendency of surrounding rural stations to be slightly higher in elevation, and thus cooler, than urban areas).

Urbanization

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


"We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

Cooling tower

These early towers were positioned either on the rooftops of buildings or as free-standing structures, supplied with air by fans or relying on natural airflow.

Cooling tower

Although these large towers are very prominent, the vast majority of cooling towers are much smaller, including many units installed on or near buildings to discharge heat from air conditioning.

Grissom Air Reserve Base

All flight operations were controlled from an air conditioned observation room in the control tower of this building, which had windows overlooking the runway and landing mat areas.

Grissom Air Reserve Base

The building contained Bink's Paint Spraying and Air Washing Equipment, including blowers, air washing and purifying devices, and exhaust fans, installed to minimize danger of explosions and inhalation of fumes.

Palo Alto, California

A third, the Stanford station, located beside Alma Street at Embarcadero Road, is used for occasional sports events (generally football) at Stanford Stadium.


We found 68 stations located  at wastewater treatment plants, where the process of waste digestion  causes temperatures to be higher than in surrounding areas.

Anaerobic digestion

Some European countries require a degree of elevated heat treatment to kill harmful bacteria in the input waste.

Anaerobic digestion

Today, anaerobic digesters are commonly found alongside farms to reduce nitrogen run-off from manure, or wastewater treatment facilities to reduce the costs of sludge disposal.

Anaerobic digestion

Thermophilic digestion takes place optimally around 49 to 57 °C, or at elevated temperatures up to 70 °C, where thermophiles are the primary microorganisms present.

Sewage sludge treatment

Many larger sites utilize the biogas for combined heat and power, using the cooling water from the generators to maintain the temperature of the digestion plant at the required 35 ± 3 °C.

Sewage sludge

In some treatment plants an Imhoff tank is used where sludge settles through a slot to the lower story or digestion chamber where it is decomposed by anaerobic bacteria, resulting in liquefaction and reduced volume of the sludge.


Numerous studies into the effect of urban heat island effect and microsite influences find they have negligible effect on long-term trends, particularly when averaged over large regions.

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

Several studies have revealed increases in the severity of the effect of heat islands with the progress of climate change.

Urban heat island

While some lines of research did not detect a significant impact, other studies have concluded that heat islands can have measurable effects on climate phenomena at the global scale.

Urban heat island

While the "heat island" warming is an important local effect, there is no evidence that it biases trends in the homogenized historical temperature record.

Urban heat island

Studies that have looked at hemispheric and global scales conclude that any urban-related trend is an order of magnitude smaller than decadal and longer time-scale trends evident in the series (e.g., Jones et al., 1990; Peterson et al., 1999).


The increase in temperatures since 1975 is a consistent feature of all reconstructions.

Hockey stick controversy

In the hockey stick controversy, the data and methods used in reconstructions of the temperature record of the past 1000 years have been disputed.

Hockey stick controversy

Reconstructions have consistently shown that the rise in the instrumental temperature record of the past 150 years is not matched in earlier centuries, and the name "hockey stick graph" was coined for figures showing a long-term decline followed by an abrupt rise in temperatures.

Hockey stick graph

Hockey stick graphs present the global or hemispherical mean temperature record of the past 500 to 2000 years as shown by quantitative climate reconstructions based on climate proxy records.

Hockey stick graph

These reconstructions have consistently shown a slow long term cooling trend changing into relatively rapid warming in the 20th century, with the instrumental temperature record by 2000 exceeding earlier temperatures.

Hockey stick graph

published on 10 February 2005 used a wavelet transform technique to reconstruct Northern Hemisphere temperatures over the last 2,000 years, combining low-resolution proxy data such as lake and ocean sediments for century-scale or longer changes, with tree ring proxies only used for annual to decadal resolution.


Natural temperature measurements also confirm the general accuracy of the instrumental temperature record.

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.

Instrumental temperature record

Another study concluded in 2006, that existing empirical techniques for validating the local and regional consistency of temperature data are adequate to identify and remove biases from station records, and that such corrections allow information about long-term trends to be preserved.

Instrumental temperature record

These datasets are updated frequently, and are generally in close agreement.

Instrumental temperature record

The temperature data for the record come from measurements from land stations and ships.

Temperature record of the past 1000 years:5

Individual proxy records, such as tree ring widths and densities used in dendroclimatology, are calibrated against the instrumental record for the period of overlap.


A large number of ancient mass extinction events have been strongly linked to global climate change.

Cretaceous–Paleogene extinction event

Other causal or contributing factors to the extinction may have been the Deccan Traps and other volcanic eruptions, climate change, and sea level change.

Cretaceous–Paleogene extinction event

"End-Cretaceous extinction in Antarctica linked to both Deccan volcanism and meteorite impact via climate change".

Cretaceous–Paleogene extinction event

The regression would also have caused climate changes, partly by disrupting winds and ocean currents and partly by reducing the Earth's albedo and increasing global temperatures.

Cretaceous–Paleogene extinction event

Species extinction at Seymour Island occurred in two pulses that coincide with the two observed warming events, directly linking the end-Cretaceous extinction at this site to both volcanic and meteorite events via climate change.

Quaternary extinction event

Among the main causes hypothesized by paleontologists are overkill by the widespread appearance of humans and natural climate change.


Because current climate change is so rapid, the way species typically adapt (eg - migration) is, in most cases, simply not be possible.

Biodiversity

Human activities therefore allow species to migrate to new areas (and thus become invasive) occurred on time scales much shorter than historically have been required for a species to extend its range.

Extinction

"Predicting patterns of long-term adaptation and extinction with population genetics".

Extinction

Meanwhile, low genetic diversity (see inbreeding and population bottlenecks) reduces the range of adaptions possible.

Invasive species

Invading species have been shown to adapt to their new environments in a remarkably short amount of time.

Nature

The combination of a high mutation rate and a horizontal gene transfer ability makes them highly adaptable, and able to survive in new environments, including outer space.


Every part of the Earth's climate system has continued warming since 1998, with 2015 shattering temperature records.

Global warming

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

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

An example of such an episode is the slower rate of surface temperature increase from 1998 to 2012, which was dubbed the global warming hiatus.

Global warming

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

Greenland ice sheet

"NASA, NOAA Analyses Reveal Record-Shattering Global Warm Temperatures in 2015".


but Antarctica is losing land ice at an accelerating rate, which has implications for sea level rise.

Antarctica

It is important to understand the various types of Antarctic ice to understand possible effects on sea levels and the implications of global cooling.

Antarctica

However, it is the outflow of the ice from the land to form the ice shelf which causes a rise in global sea level.

Antarctica

If all of this ice were melted, sea levels would rise about 60 m (200 ft).

Sea level rise

Warming beyond the 2 °C (3.6 °F) target potentially lead to rates of sea-level rise dominated by ice loss from Antarctica.

Sea level rise

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


[Ice] is expanding in much of Antarctica, contrary to the widespread public belief that global warming is melting the continental ice cap.

Antarctic ice sheet

In contrast to the melting of the Arctic sea ice, sea ice around Antarctica has been expanding as of 2013[update].

Antarctica

As a result of continued warming, the polar ice caps melted and much of Gondwana became a desert.

Antarctica

Sea ice extent expands annually in the Antarctic winter and most of this ice melts in the summer.

Antarctica

The amount of surface warming in West Antarctica, while large, has not led to appreciable melting at the surface, and is not directly affecting the West Antarctic Ice Sheet's contribution to sea level.

Global warming

The remainder of the additional energy has melted ice and warmed the continents and the atmosphere.


The majority of peer reviewed research at the time predicted warming due to increasing CO2.

Global cooling

A survey of peer-reviewed scientific papers published between 1965 and 1979 shows that the large majority of research at the time predicted that the earth would warm as carbon-dioxide levels rose — as indeed it has."

Global cooling

The 1970 Study of Critical Environmental Problems reported the possibility of warming from increased carbon dioxide, but no concerns about cooling, setting a lower bound on the beginning of interest in "global cooling".

Global cooling

Academic analysis of the peer-reviewed studies published at that time shows that most papers examining aspects of climate during the 1970s were either neutral or showed a warming trend.

Global warming

This phrase next appeared in a November 1957 report in The Hammond Times which described Roger Revelle's research into the effects of increasing human-caused CO 2 emissions on the greenhouse effect: "a large scale global warming, with radical climate changes may result".

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.


"An article in Science magazine illustrated that a rise in carbon dioxide did not precede a rise in temperatures, but actually lagged behind temperature rises by 200 to 1000 years.

Effects of global warming

In 2019 a paper published in the journal Science found the oceans are heating 40% faster than the IPCC predicted just five years before.

Global warming controversy

Studies of the Vostok ice core show that at the "beginning of the deglaciations, the CO 2 increase either was in phase or lagged by less than ~1000 years with respect to the Antarctic temperature, whereas it clearly lagged behind the temperature at the onset of the glaciations".

Global warming controversy

Recent warming is followed by carbon dioxide levels with only a 5 months delay.

Global warming

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

Scientific consensus on climate change:655

Scientific consensus on climate change

Carbon dioxide concentrations were relatively stable for the past 10,000 years but then began to increase rapidly about 150 years ago…as a result of fossil fuel consumption and land use change.


When the Earth comes out of an ice age, the warming is not initiated by CO2 but by changes in the Earth's orbit.

Global cooling

Orbital forcing refers to the slow, cyclical changes in the tilt of Earth's axis and shape of its orbit.

Ice age

The consensus is that several factors are important: atmospheric composition, such as the concentrations of carbon dioxide and methane (the specific levels of the previously mentioned gases are now able to be seen with the new ice core samples from EPICA Dome C in Antarctica over the past 800,000 years); changes in the earth's orbit around the Sun known as Milankovitch cycles; the motion of tectonic plates resulting in changes in the relative location and amount of continental and oceanic crust on the earth's surface, which affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth–Moon system; the impact of relatively large meteorites and volcanism including eruptions of supervolcanoes.

Ice age

The Milankovitch cycles are a set of cyclic variations in characteristics of the Earth's orbit around the Sun.

Ice age

In particular, during the last 800,000 years, the dominant period of glacial–interglacial oscillation has been 100,000 years, which corresponds to changes in Earth's orbital eccentricity and orbital inclination.

Ice age

He attempted to show that they originated from changes in Earth's orbit.


The warming causes the oceans to release CO2.

Anoxic event

The trigger for these mass extinctions appears to be a warming of the ocean caused by a rise of carbon dioxide levels to about 1000 parts per million.

Anoxic event

The effect of this warm water propagates through the ocean, and reduces the amount of CO 2 that the oceans can hold in solution, which makes the oceans release large quantities of CO 2 into the atmosphere in a geologically short time (tens or thousands of years).

Global warming

As more CO2 and heat are absorbed by the ocean, it is acidifying and ocean circulation can change, changing the rate at which the ocean can absorb atmospheric carbon.

Global warming

Higher atmospheric CO2 concentrations have led to an increase in dissolved CO2, which causes ocean acidification.

Global warming

These feedbacks can change the role of the oceans in taking up atmospheric CO 2 making it very difficult to predict how the ocean carbon cycle will operate in the future.


The CO2 amplifies the warming and mixes through the atmosphere, spreading warming throughout the planet.

Carbon dioxide in Earth's atmosphere

The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond the temperature it would have in the absence of its atmosphere.

Carbon dioxide

Absorption of infrared light at the vibrational frequencies of atmospheric carbon dioxide traps energy near the surface, warming the surface and the lower atmosphere.

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.

Greenhouse effect

The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.

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.


So CO2 causes warming AND rising temperature causes CO2 rise.

Carbon dioxide

Carbon dioxide

Not only do increasing carbon dioxide concentrations lead to increases in global surface temperature, but increasing global temperatures also cause increasing concentrations of carbon dioxide.

Climate change feedback

The higher CO2 levels led to an additional climate warming ranging between 0.1° and 1.5 °C.

Global warming

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

Greenhouse gas

During the late 20th century, a scientific consensus evolved that increasing concentrations of greenhouse gases in the atmosphere cause a substantial rise in global temperatures and changes to other parts of the climate system, with consequences for the environment and for human health.


Overall, about 90% of the global warming occurs after the CO2 increase.

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.

Global warming

Global warming

As of 2011, the concentrations of CO2 and methane had increased by about 40% and 150%, respectively, since pre-industrial times.

Global warming

Global anthropogenic greenhouse gas emissions in 2010 were equivalent to 49 billion tonnes of carbon dioxide (using the most recent global warming potentials over 100 years from the AR5 report).

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.


"His [Dr Spencer's] latest research demonstrates that – in the short term, at any rate –  the temperature feedbacks that the IPCC imagines will greatly amplify  any initial warming caused by CO2 are net-negative, attenuating the  warming they are supposed to enhance.

Climate change feedback

Climate change feedback is important in the understanding of global warming because feedback processes may amplify or diminish the effect of each climate forcing, and so play an important part in determining the climate sensitivity and future climate state.

Climate change feedback

Water vapor feedback is strongly positive, with most evidence supporting a magnitude of 1.5 to 2.0 W/m2/K, sufficient to roughly double the warming that would otherwise occur.

Climate change feedback

Both theory and climate models indicate that global warming will reduce the rate of temperature decrease with height, producing a negative lapse rate feedback that weakens the greenhouse effect.

Greenhouse gas

Scientific consensus on climate change:38

Scientific consensus on climate change

It said that Continued emission of greenhouse gases will cause further warming and long-lasting changes in all components of the climate system, increasing the likelihood of severe, pervasive and irreversible impacts for people and ecosystems.


His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

Climate sensitivity

Without feedbacks the radiative forcing of approximately 3.7 W/m2, due to doubling CO 2 from the pre-industrial 280 ppm, would eventually result in roughly 1 °C global warming.

Climate sensitivity

In his first paper on the matter, he estimated that global temperature would rise by around 5 to 6 °C (9.0 to 10.8 °F) if the quantity of CO 2 was doubled.

Climate sensitivity

The 1990 IPCC First Assessment Report estimated that equilibrium climate sensitivity to a doubling of CO 2 lay between 1.5 and 4.5 °C (2.7 and 8.1 °F), with a "best guess in the light of current knowledge" of 2.5 °C (4.5 °F).

IPCC Third Assessment Report

The TAR estimate for the climate sensitivity is 1.5 to 4.5 °C; and the average surface temperature is projected to increase by 1.4 to 5.8 Celsius degrees over the period 1990 to 2100, and the sea level is projected to rise by 0.1 to 0.9 metres over the same period.

Kyoto Protocol

The "likely" range (as assessed to have a greater than 66% probability of being correct, based on the IPCC's expert judgment) is a projected increase in global mean temperature over the 21st century of between 1.1 and 6.4 °C.


Climate sensitivity can be calculated empirically by comparing past temperature change to natural forcings at the time.

Climate sensitivity

Climate sensitivity is the globally averaged temperature change in response to changes in radiative forcing, which can occur, for instance, due to increased levels of carbon dioxide (CO 2).

Climate sensitivity

One way is to use estimates of global radiative forcing and temperature directly.

Climate sensitivity

Ignoring these factors causes lower estimates of climate sensitivity when using radiative forcing and temperature records from the historical period.

Climate sensitivity

Climate sensitivity can be estimated using observed temperature rise, observed ocean heat uptake, and modeled or observed radiative forcing.

Climate sensitivity

Climate sensitivity is typically estimated in three ways; by using observations taken during the industrial age, by using temperature and other data from the Earth's past and by modelling the climate system in computers.


Some global warming 'skeptics' argue that the Earth's climate sensitivity is so low that a doubling of atmospheric CO2 will result in a surface temperature change on the order of 1°C or less, and that therefore global warming is nothing to worry about.

Climate sensitivity

The equilibrium climate sensitivity (ECS) refers to the equilibrium change in global mean near-surface air temperature that would result from a sustained doubling of the atmospheric equivalent CO 2 concentration (ΔT2×).

Climate sensitivity

The sensitivity of temperature to atmospheric gasses, most notably CO 2, is often expressed in terms of the change in temperature per doubling of the concentration of the gas.

Climate sensitivity

Climate sensitivity

Climate sensitivity

The transient climate response (TCR) is the amount of temperature increase that might occur at the time when CO2 doubles, having increased gradually by 1% each year.


And  since the last ice age ended almost exactly 11,500 years ago…" (Ice Age Now)

Earth

The last continental glaciation ended 10,000 years ago.

Ice age

The last cold episode of the last glacial period ended about 10,000 years ago.

Ice age

During the most recent North American glaciation, during the latter part of the Last Glacial Maximum (26,000 to 13,300 years ago), ice sheets extended to about 45th parallel north.

Ice age

Accordingly, at glacial times the humid climatic belt that today is situated several latitude degrees further to the S, was shifted much further to the N. Although the last glacial period ended more than 8,000 years ago, its effects can still be felt today.

Ice age

The earth is currently in an interglacial, and the last glacial period ended about 10,000 years ago.


The warming effect from more CO2 greatly outstrips the influence from changes in the Earth's orbit or solar activity, even if solar levels were to drop to Maunder Minimum levels.

Attribution of recent climate change:203

Attribution of recent climate change

If the Sun was responsible for observed warming, warming of the troposphere at the surface and warming at the top of the stratosphere would be expected as increase solar activity would replenish ozone and oxides of nitrogen.

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.

Climate change feedback

The higher CO2 levels led to an additional climate warming ranging between 0.1° and 1.5 °C.

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.

Ice age

The consensus is that several factors are important: atmospheric composition, such as the concentrations of carbon dioxide and methane (the specific levels of the previously mentioned gases are now able to be seen with the new ice core samples from EPICA Dome C in Antarctica over the past 800,000 years); changes in the earth's orbit around the Sun known as Milankovitch cycles; the motion of tectonic plates resulting in changes in the relative location and amount of continental and oceanic crust on the earth's surface, which affect wind and ocean currents; variations in solar output; the orbital dynamics of the Earth–Moon system; the impact of relatively large meteorites and volcanism including eruptions of supervolcanoes.