Severe storms, floods and agricultural losses may cost a great deal of money, but such extreme weather events—and their resulting costs—are dramatically declining as the Earth modestly warms.

Effects of global warming on human health:294

For example, the heat wave that passed through Europe in 2003 cost 13 billion euros in uninsured agriculture losses.

Effects of global warming on humans

Increased extreme weather means more water falls on hardened ground unable to absorb it, leading to flash floods instead of a replenishment of soil moisture or groundwater levels.

Flood

Economic hardship due to a temporary decline in tourism, rebuilding costs, or food shortages leading to price increases is a common after-effect of severe flooding.

Severe weather

In economic terms, they can cost many billions of dollars: a drought in the United States in 1988 caused over $40 billion in losses, exceeding the economic totals of Hurricane Andrew, the Great Flood of 1993, and the 1989 Loma Prieta earthquake.

Weather

Climate change caused by human activities that emit greenhouse gases into the air is expected to affect the frequency of extreme weather events such as drought, extreme temperatures, flooding, high winds, and severe storms.


alarmists here are taking overwhelmingly good news about global warming improving plant health and making it seem like this good news is actually bad news because healthier plants mean more pollen.

Biodiversity

Biodiversity's relevance to human health is becoming an international political issue, as scientific evidence builds on the global health implications of biodiversity loss.

Climate change denial

Even if the current and future projected human effects on Earth's climate are not negligible, the changes are generally going to be good for us.

Climate change in Australia

[clarification needed] Predictions measuring the effects of global warming on Australia assert that global warming will negatively impact the continent's environment, economy, and communities.

Effects of global warming on human health:556

"Doctors Warn Climate Change Threatens Public Health; Physicians are noticing an influx of patients whose illnesses are directly or indirectly related to global warming".

Effects of global warming

This in combination with extreme weather events, leads to negative effects on human health.


Since the end of 2012, moreover, total polar ice extent has largely remained above the post-1979 average.

Beaufort Sea

Arctic sea ice extent averaged for September 2012 was 3.61 million square kilometers (1.39 million square miles).

Climate change in the Arctic

It continued to fall, bottoming out on 16 September 2012 at 3.41 million square kilometers (1.32 million square miles), or 760,000 square kilometers (293,000 square miles) below the previous low set on 18 September 2007 and 50% below the 1979–2000 average.

Climate change in the Arctic

From 1979–1996, the average per decade decline in entire ice coverage was a 2.2% decline in ice extent and a 3% decline in ice area.

Climate change in the Arctic

"Arctic sea ice volume now one-fifth its 1979 level".

Climate change in the Arctic

Since 1979, the ice volume has shrunk by 80% and in just the past decade the volume declined by 36% in the autumn and 9% in the winter.


The late 1970s marked the end of a 30-year cooling trend.

Global cooling

Concern peaked in the early 1970s, though "the possibility of anthropogenic warming dominated the peer-reviewed literature even then" (a cooling period began in 1945, and two decades of a cooling trend suggested a trough had been reached after several decades of warming).

Global cooling

"During the last 20-30 years, world temperature has fallen, irregularly at first but more sharply over the last 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).

Quaternary glaciation

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

Quaternary glaciation

It is possible that the current cooling trend may be interrupted by an interstadial in about 60,000 years, with the next glacial maximum reached only in about 100,000 years.


As a result, the polar ice caps were quite likely more extensive than they had been since at least the 1920s.

Cambrian

There were likely polar ice caps and a series of glaciations, as the planet was still recovering from an earlier Snowball Earth.

Ice age

In the terminology of glaciology, ice age implies the presence of extensive ice sheets in both northern and southern hemispheres.

Ice age

There were extensive polar ice caps at intervals from 360 to 260 million years ago in South Africa during the Carboniferous and early Permian Periods.

Polar ice cap

Both 2008 and 2009 had a minimum Arctic sea ice extent somewhat above that of 2007.

Polar ice cap

The single-day maximum extent in 2014 was reached on 20 Sep, according to NSIDC data, when the sea ice covered 7.78 million square miles (20.14 million square kilometers).


Beginning in 2005, however, polar ice modestly receded for several years.

Arctic Ocean

Polar Discovery "Continued Sea Ice Decline in 2005".

Retreat of glaciers since 1850

Ice cover decreased to 297 km2 (115 sq mi) by 1987–1988 and to 245 km2 (95 sq mi) by 2005, 50% of the 1850 area.

Retreat of glaciers since 1850

The net loss in volume and hence sea level contribution of the Greenland Ice Sheet (GIS) has doubled in recent years from 90 km3 (22 cu mi) per year in 1996 to 220 km3 (53 cu mi) per year in 2005.

Retreat of glaciers since 1850

The Trift Glacier had the greatest recorded retreat, losing 350 m (1,150 ft) of its length between the years 2003 and 2005.

Retreat of glaciers since 1850

This long-term average was markedly surpassed in recent years with the glacier receding 30 m (98 ft) per year during the period between 1999–2005.


receding polar ice caps have little if any negative impact on human health and welfare, and likely a positive benefit

Effects of global warming on human health:0

The effects of global warming include its effects on human health.

Effects of global warming on human health:270

There are, however, some positive possible aspects to climate change as well.

Effects of global warming on human health:297

This could negatively affect the affordability of food and the subsequent health of the population.

Effects of global warming on human health:397

Floods have short and long term negative implications to peoples' health and well being.

Effects of global warming on human health:437

These melting glaciers have many social and ecological consequences that directly or indirectly impact the health and well-being of humans.


Yet, according to NASA, only one temperature sensing station is necessary for the two cities and the vast area between them to be adequately represented in their network.”

City

The temperature in New York City exceeds nearby rural temperatures by an average of 2–3 °C and at times 5–10 °C differences have been recorded.

James Hansen

They concluded that global mean temperatures can be determined even though meteorological stations are typically in the Northern hemisphere and confined to continental regions.

Mars

In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month.

NASA Deep Space Network

Deep space missions are visible for long periods of time from a large portion of the Earth's surface, and so require few stations (the DSN has only three main sites).

NASA Deep Space Network

Three were located at Goldstone, and one each at Canberra and Madrid.


“In their award winning book, ‘Taken By Storm’ (2007), Canadian researchers Christopher Essex and Ross McKitrick explain: ‘Temperature is not an amount of something [like height or weight].

Storm

Lately, the temperature criterion has fallen out of the definition across the United States Bomb cyclone – A rapid deepening of a mid-latitude cyclonic low-pressure area, typically occurring over the ocean, but can occur over land.

Temperature

Nevertheless, a thermodynamic temperature does in fact have a definite numerical value that has been arbitrarily chosen by tradition and is dependent on the property of a particular materials; it is simply less arbitrary than relative "degrees" scales such as Celsius and Fahrenheit.

Temperature

It has the symbol K. For everyday applications, it is often convenient to use the Celsius scale, in which 0 °C corresponds very closely to the freezing point of water and 100 °C is its boiling point at sea level.

Temperature

The most common scales are the Celsius scale (formerly called centigrade), denoted °C, the Fahrenheit scale (denoted °F), and the Kelvin scale (denoted K), the latter of which is predominantly used for scientific purposes by conventions of the International System of Units (SI).

Tropical cyclone

This upper bound is called the "maximum potential intensity", v p {\displaystyle v_{p}} , and is given by v p 2 = C k C d T s − T o T o Δ k {\displaystyle v_{p}^{2}={\frac {C_{k}}{C_{d}}}{\frac {T_{s}-T_{o}}{T_{o}}}\Delta k} where T s {\displaystyle T_{s}} is the temperature of the sea surface, T o {\displaystyle T_{o}} is the temperature of the outflow ([K]), Δ k {\displaystyle \Delta k} is the enthalpy difference between the surface and the overlying air ([J/kg]), and C k {\displaystyle C_{k}} and C d {\displaystyle C_{d}} are the surface exchange coefficients (dimensionless) of enthalpy and momentum, respectively.


“Temperature, like viscosity and density, and of course phone numbers, is not something that can be meaningfully averaged. ‘

Density

The density of a material varies with temperature and pressure.

Density

The density of an ideal gas is ρ = M P R T , {\displaystyle \rho ={\frac {MP}{RT}},} where M is the molar mass, P is the pressure, R is the universal gas constant, and T is the absolute temperature.

Population density

Population density (in agriculture: standing stock and standing crop) is a measurement of population per unit area, or exceptionally unit volume; it is a quantity of type number density.

Thermodynamic temperature

Averaged across any bulk quantity of a gas, the internal thermal motions of molecules have zero net effect upon the temperature, pressure, or volume of a gas.

Viscosity

An elementary calculation for a dilute gas at temperature T {\displaystyle T} and density ρ {\displaystyle \rho } gives μ = α ρ λ 2 k B T π m , {\displaystyle \mu =\alpha \rho \lambda {\sqrt {\frac {2k_{\text{B}}T}{\pi m}}},} where k B {\displaystyle k_{\text{B}}} is the Boltzmann constant, m {\displaystyle m} the molecular mass, and α {\displaystyle \alpha } a numerical constant on the order of 1 {\displaystyle 1} .


“Even if you could calculate some sort of meaningful global temperature statistic, the figure would be unimportant.

City

Cities are responsible for a substantial portion of the emissions responsible for global warming.

Figure of the Earth

The primary utility of this improved accuracy was to provide geographical and gravitational data for the inertial guidance systems of ballistic missiles.

Figure of the Earth

While it is the surface on which Earth measurements are made, mathematically modeling it while taking the irregularities into account would be extremely complicated.

Figure of the Earth

The latter is particularly important because optical instruments containing gravity-reference leveling devices are commonly used to make geodetic measurements.

Figure of the Earth

However, a more accurate figure is needed for measuring distances and areas on the scale beyond the purely local.


The earth is 15 years from a “mini ice-age” that will cause bitterly cold winters during which rivers such as the Thames freeze over, scientists have predicted.

Little Ice Age

Canals and rivers in Great Britain and the Netherlands were frequently frozen deeply enough to support ice skating and winter festivals.

River Thames

During a series of cold winters the Thames froze over above London Bridge: in the first Frost Fair in 1607, a tent city was set up on the river, along with a number of amusements, including ice bowling.

River Thames

After temperatures began to rise again, starting in 1814, the river stopped freezing over.

Winter

In the UK, snow drifts remained on hills until late July, and the Thames froze in September.

Winter

The Thames remained frozen over for about 8 weeks.


In recent decades this warming has been accompanied by a constant rise in the sea level and, it would appear, by an increase of extreme weather events, even if a scientifically determinable cause cannot be assigned to each particular phenomenon.

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

Further examples include sea level rise, widespread melting of snow and land ice, increased heat content of the oceans, increased humidity, and the earlier timing of spring events, such as the flowering of plants.

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.

Global warming

Not only does this increase the absorption of sunlight, it also increases melting and sea level rise.


Concentrated in the atmosphere, these gases do not allow the warmth of the sun’s rays reflected by the earth to be dispersed in space.

Earth

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

Earth

The resultant molecular oxygen (O 2) accumulated in the atmosphere and due to interaction with ultraviolet solar radiation, formed a protective ozone layer (O 3) in the upper atmosphere.

Ozone

Ozone acts as a greenhouse gas, absorbing some of the infrared energy emitted by the earth.

Scientific consensus on climate change:714

Scientific consensus on climate change

These human activities have significantly increased the concentration of "greenhouse gases" in the atmosphere.

Sulfur dioxide

There, it condenses to form clouds, and is a key component of chemical reactions in the planet's atmosphere and contributes to global warming.


The melting in the polar ice caps and in high altitude plains can lead to the dangerous release of methane gas

Climate change in the Arctic

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

Climate change in the Arctic

Potential methane releases from the region, especially through the thawing of permafrost and methane clathrates, may occur.

Glacier

Within high-altitude and Antarctic environments, the seasonal temperature difference is often not sufficient to release meltwater.

Retreat of glaciers since 1850

The potential for major sea level rise depends mostly on a significant melting of the polar ice caps of Greenland and Antarctica, as this is where the vast majority of glacial ice is located.

Thaumasia quadrangle

On Mars, heat from the impact melts ice in the ground.


Each year sees the disappearance of thousands of plant and animal species which we will never know, which our children will never see, because they have been lost for ever.

Extinction

According to the 2019 Global Assessment Report on Biodiversity and Ecosystem Services by IPBES, the biomass of wild mammals has fallen by 82%, natural ecosystems have lost about half their area and a million species are at risk of extinction—all largely as a result of human actions.

Extinction

Twenty-five percent of plant and animal species are threatened with extinction.

Extinction

In June 2019, one million species of plants and animals were at risk of extinction.

Human overpopulation

Worst of all, we have driven the rate of biological extinction, the permanent loss of species, up several hundred times beyond its historical levels, and are threatened with the loss of a majority of all species by the end of the 21st century."

Human overpopulation

Present extinction rates may be as high as 140,000 species lost per year due to human activity, such as slash-and-burn techniques that sometimes are practiced by shifting cultivators, especially in countries with rapidly expanding rural populations, which have reduced habitat in tropical forests.


Many of the world’s coral reefs are already barren or in a state of constant decline.

Coral reef

Tropical waters contain few nutrients yet a coral reef can flourish like an "oasis in the desert".

Coral reef

For example, Midway Atoll in Hawaii supports nearly three million seabirds, including two-thirds (1.5 million) of the global population of Laysan albatross, and one-third of the global population of black-footed albatross.

Coral

Approximately 10% of the world's coral reefs are dead.

Coral

Aquaculture is showing promise as a potentially effective tool for restoring coral reefs, which have been declining around the world.

Marine habitats

This can rapidly result in transitions to barren landscapes where relatively few species persist.


Seventeen of the 18 warmest years have occurred since 2000.

2006 European heat wave

The autumn of 2006 was the warmest in recorded history.

Climate change in the United States

As of 2012[update], the thirteen warmest years for the entire planet have all occurred since 1998, transcending those from 1880.

Constanța

Summer (early June to mid September) is hot and sunny with a July and August average of 23 °C (73 °F).

Constanța

Four of the warmest 7 years since 1889 occurred after the year 2000 (2000, 2001, 2007 and 2008).

Instrumental temperature record

2016's record meant that 16 of the 17 warmest years have occurred since 2000, 2017 being the third-hottest year on record meant that 17 of the last 18 warmest years have occurred since 2000.


Eleven percent of all global greenhouse gas emissions caused by humans are caused by deforestation — comparable to the emissions from all of the cars and trucks on the planet.

Deforestation

Tropical deforestation is responsible for approximately 20% of world greenhouse gas emissions.

Global warming

Of these emissions, 65% was carbon dioxide from fossil fuel burning and industry, 11% was carbon dioxide from land use change, which is primarily due to deforestation, 16% was from methane, 6.2% was from nitrous oxide, and 2.0% was from fluorinated gases.

Greenhouse gas

Land-use change, such as deforestation, caused about 31% of cumulative emissions over 1870–2017, coal 32%, oil 25%, and gas 10%.

Greenhouse gas

The estimate of total CO 2 emissions includes biotic carbon emissions, mainly from deforestation.

Greenhouse gas

The vast majority of anthropogenic carbon dioxide emissions come from combustion of fossil fuels, principally coal, oil, and natural gas, with additional contributions coming from deforestation, changes in land use, soil erosion and agriculture (including livestock).


Eleven percent of the world’s population is currently vulnerable to climate change impacts such as droughts, floods, heat waves, extreme weather events and sea-level rise.

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

Many physical impacts of global warming are already visible, including extreme weather events, glacier retreat, changes in the timing of seasonal events (e.g., earlier flowering of plants), sea level rise, and declines in Arctic sea ice extent.

Global warming

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

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.

Scientific consensus on climate change:228

Scientific consensus on climate change

The letter goes on to warn of predicted impacts on the United States such as sea level rise and increases in extreme weather events, water scarcity, heat waves, wildfires, and the disturbance of biological systems.


Just 0.7% of the world’s forests are coastal mangroves, yet they store up to 10 times as much carbon per hectare as tropical forests.

Amazon rainforest

Amazonian forests are estimated to have accumulated 0.62 ± 0.37 tons of carbon per hectare per year between 1975 and 1996.

Forest

Net primary production is estimated at 21.9 gigatonnes carbon per year for tropical forests, 8.1 for temperate forests, and 2.6 for boreal forests.

Mangrove

Mangrove forests are an important part of the cycling and storage of carbon in tropical coastal ecosystems.

Mire

Tropical peatlands comprise 0.25% of Earth’s terrestrial land surface but store 3% of all soil and forest carbon stocks and are mostly located in low-income countries.

Seagrass

Per hectare, it holds twice as much carbon dioxide as rain forests and can sequester about 27.4 million tons of CO2 annually.


An area of coastal ecosystems larger than New York City is destroyed every year, removing an important buffer from extreme weather for coastal communities and releasing carbon dioxide into the atmosphere.

Deforestation

Both the decay and the burning of wood release much of this stored carbon back into the atmosphere.

Ecology

For example, through the early-mid Eocene volcanic outgassing, the oxidation of methane stored in wetlands, and seafloor gases increased atmospheric CO2 (carbon dioxide) concentrations to levels as high as 3500 ppm.

Marine pollution

"special protection and perservation of peat bogs, wetlands, marshlands and mangrove swamps to ensure carbon dioxide is absorbed from the atmosphere."

Sea level rise

Such impacts include increased coastal erosion, higher storm-surge flooding, inhibition of primary production processes, more extensive coastal inundation, changes in surface water quality and groundwater characteristics, increased loss of property and coastal habitats, increased flood risk and potential loss of life, loss of non-monetary cultural resources and values, impacts on agriculture and aquaculture through decline in soil and water quality, and loss of tourism, recreation, and transportation functions.

Urbanization

Furthermore, as algal blooms die, CO2 is produced, causing a more acidic environment, a process known as acidification.


195 countries signed the 2015 Paris Agreement, agreeing to limit global warming and adapt to climate change, partly by protecting nature.

2015 United Nations Climate Change Conference:2

The conference negotiated the Paris Agreement, a global agreement on the reduction of climate change, the text of which represented a consensus of the representatives of the 196 attending parties.

2015 United Nations Climate Change Conference:36

On 12 December 2015, the participating 196 countries agreed, by consensus, to the final global pact, the Paris Agreement, to reduce emissions as part of the method for reducing greenhouse gas.

2015 United Nations Climate Change Conference:4

On 22 April 2016 (Earth Day), 174 countries signed the agreement in New York, and began adopting it within their own legal systems (through ratification, acceptance, approval, or accession).

Global warming

In 2015 all UN countries negotiated the Paris Agreement, which aims to keep climate change well below 2 °C.

United Nations Framework Convention on Climate Change:43

In 2015, all (then) 196 parties to the convention came together for the UN Climate Change Conference in Paris 30 November - 12 December and adopted by consensus the Paris Agreement, aimed at limiting global warming to less than two degrees Celsius, and pursue efforts to limit the rise to 1.5 degrees Celsius.


Natural climate solutions like ending deforestation and restoring degraded forests could, at the global level, create 80 million jobs, bring 1 billion people out of poverty and add US$ 2.3 trillion in productive growth.

Climate change mitigation

Globally, there are an estimated 3 million direct jobs in renewable energy industries, with about half of them in the biofuels industry.

Human overpopulation

Since 1980, the global economy has grown by 380 percent, but the number of people living on less than 5 US dollars a day increased by more than 1.1 billion.

Sustainability

This included the following seventeen goals: Poverty – End poverty in all its forms everywhere Food – End hunger, achieve food security and improved nutrition and promote sustainable agriculture Health – Ensure healthy lives and promote well-being for all at all ages Education – Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all Women – Achieve gender equality and empower all women and girls Water – Ensure availability and sustainable management of water and sanitation for all Energy – Ensure access to affordable, reliable, sustainable and modern energy for all Economy – Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all Infrastructure – Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation Inequality – Reduce inequality within and among countries Habitation – Make cities and human settlements inclusive, safe, resilient and sustainable Consumption – Ensure sustainable consumption and production patterns Climate – Take urgent action to combat climate change and its impacts, ensuring that both mitigation and adaptation strategies are in place Marine-ecosystems – Conserve and sustainably use the oceans, seas and marine resources for sustainable development Ecosystems – Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss Institutions – Promote peaceful and inclusive societies for sustainable development, provide access to justice for all and build effective, accountable and inclusive institutions at all levels Sustainability – Strengthen the means of implementation and revitalize the global partnership for sustainable development As of August 2015[update], there were 169 proposed targets for these goals and 304 proposed indicators to show compliance.

Sustainable Development Goals

The Economist estimated that alleviating poverty and achieving the other sustainable development goals will require about US$2–3 trillion per year for the next 15 years which they called "pure fantasy".

Sustainable Development Goals

Estimates for providing clean water and sanitation for the whole population of all continents have been as high as US$200 billion.


CO2 emissions from all commercial operations in 2018 totaled 918 million metric tons—2.4% of global CO2 emissions from fossil fuel use.

Electricity sector in Argentina

In 2011, according to the International Energy Agency, the actual CO2 emissions from electricity generation were 67.32 million metric tons, a share of 36.7% of the countries' total CO2 emissions from fuel combustion.

Environmental impact of aviation

In 2018, global commercial operations emitted 918 million tonnes (Mt) of CO₂, 2.4% of all CO₂ emissions: 747 Mt for passenger transport and 171 Mt for freight operations.

Environmental impact of aviation

In 2018, CO2 emissions totalled 747 million tonnes for passenger transport, for 8.5 trillion revenue passenger kilometres (RPK), giving an average of 88 gram CO2 per RPK.

Gasoline

The U.S. EIA estimates that U.S. motor gasoline and diesel (distillate) fuel consumption for transportation in 2015 resulted in the emission of about 1,105 million metric tons of CO2 and 440 million metric tons of CO2, respectively, for a total of 1,545 million metric tons of CO2.

Greenhouse gas emissions by the United States:0

The United States produced 5.4 billion metric tons of carbon dioxide equivalent greenhouse gas (GHG) emissions in 2018, the second largest in the world after China and among the worst countries by greenhouse gas emissions per person.


Flights departing airports in the United States and its territories emitted about one-quarter (24%) of global passenger transport-related CO2, two-thirds of which came from domestic flights.

Airline

Currently, the aviation sector, including US domestic and global international travel, make approximately 1.6 percent of global anthropogenic GHG emissions per annum.

Environmental impact of aviation

Environmental impact of aviation

In 1999 the contribution of civil aircraft-in-flight to global CO2 emissions was estimated to be around two percent.

Environmental impact of aviation

Environmental impact of aviation

In 2018, the US airlines had a fuel consumption of 58 mpg‑US (4.06 L/100 km) per revenue passenger for domestic flights, or 32.5 g of fuel per km, generating 102 g CO₂ / RPK of emissions.


The top five countries for passenger aviation-related carbon emissions were rounded out by China, the United Kingdom, Japan, and Germany.

Environmental impact of aviation in the United Kingdom:131

Air transport in the UK accounted for 6.3 per cent of all UK carbon emissions in 2006.

Environmental impact of aviation

In Europe, the average airline fuel consumption per passenger in 2017 was 3.4 L/100 km (69 mpg‑US), 24% less than in 2005, but as the traffic grew by 60% to 1,643 billion passenger kilometres, CO₂ emissions were up by 16% to 163 million tonnes for 99.8 g/km CO₂ per passenger.

Germany

Nevertheless, the country's total greenhouse gas emissions were the highest in the EU in 2017[update].

Greenhouse gas

Over this time period, the US accounted for 28% of emissions; the EU, 23%; Russia, 11%; China, 9%; other OECD countries, 5%; Japan, 4%; India, 3%; and the rest of the world, 18%.

Greenhouse gas

Based on annual emissions data from the year 2004, and on a per-capita consumption basis, the top-5 emitting countries were found to be (in tCO 2 per person, per year): Luxembourg (34.7), the US (22.0), Singapore (20.2), Australia (16.7), and Canada (16.6).


43% of CO2 from commercial aviation was linked to passenger movement in narrowbody aircraft, followed by widebody jets (33%), and regional aircraft (5%).

Aircraft lease

At the end of July 2015, the top 50 aircraft lessors managed 8,184 aircraft: 511 turboprop regional airliners, 792 regional jets, 5,612 narrowbody and 1,253 widebody airliners.

Airliner

Narrowbody are dominant with 16,235, followed by 5,581 Widebodies, 3,743 Turboprops, 3,565 Regional jets and 399 Others.

Environmental impact of aviation

Environmental impact of aviation

Today, turboprop aircraft – probably in part because of their lower cruising speeds and altitudes (similar to the earlier piston-powered airliners) compared to jet airliners – play an obvious role in the overall fuel efficiency of major airlines that have regional carrier subsidiaries.

Wide-body aircraft

A wide-body aircraft, also known as a twin-aisle aircraft, is a jet airliner with a fuselage wide enough to accommodate two passenger aisles with seven or more seats abreast.


The planet's average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the 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.

Earth

The highest air temperature ever measured on Earth was 56.7 °C (134.1 °F) in Furnace Creek, California, in Death Valley, in 1913.

Fahrenheit

A temperature interval of 1 °F is equal to an interval of 5⁄9 degrees Celsius.

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.

Scientific consensus on climate change:150

Scientific consensus on climate change

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


Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010.

2000s (decade)

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

2000s (decade)

In December 2009, the World Meteorological Organization (WMO) announced that the 2000s may have been the warmest decade since records began in 1850, with four of the five warmest years since 1850 having occurred in this decade.

2010 Northern Hemisphere heat waves

The temperature was the hottest measured in 68 years.

Global warming

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

Global warming

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


Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months.

January

It is, on average, the coldest month of the year within most of the Northern Hemisphere (where it is the second month of winter) and the warmest month of the year within most of the Southern Hemisphere (where it is the second month of summer).

Kansas City, Missouri

The coldest month of the year is January, with an average temperature of 31 °F (−0.6 °C).

Month

It has 12 months, broken down into two groups of six often termed "winter months" and "summer months".

New York City

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

Portland, Oregon

The months of June, July, August and September account for a combined 4.49 inches (114 mm) of total rainfall – only 12% of the 36.03 in (915 mm) of the precipitation that falls throughout the year.


The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969.

Effects of global warming on oceans

In another study, results estimate the heat content of the ocean in the upper 700 meters has increased significantly from 1955–2010.

Eocene

These isotope changes occurred due to the release of carbon from the ocean into the atmosphere that led to a temperature increase of 4-8 °C (7-14 °F) at the surface of the ocean.

Global warming

Warming of the ocean accounts for about 93% of the increase in the Earth's energy inventory between 1971 and 2010 (high confidence), with warming of the upper (0 to 700 m) ocean accounting for about 64% of the total.

Indian Ocean

Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, at about 1.2 °C (34.2 °F) (compared to 0.7 °C (33.3 °F) for the warm pool region) during 1901–2012.

Sea level rise

Heat gets transported into deeper parts of the ocean by winds and currents, and some of it reaches depths of more than 2,000 m (6,600 ft).


The Greenland and Antarctic ice sheets have decreased in mass.

Greenland ice sheet

From about 11 million years ago to 10 million years ago, the Greenland Ice Sheet was greatly reduced in size.

Greenland ice sheet

Also snowfall was unusually low, which led to unprecedented negative −65 km3 (−15.6 cu mi) Surface Mass Balance.

Greenland ice sheet

Analysis of gravity data from GRACE satellites indicates that the Greenland ice sheet lost approximately 2900 Gt (0.1% of its total mass) between March 2002 and September 2012.

Ice sheet

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

Retreat of glaciers since 1850

"Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE".


Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.

Glacier

Extensive glaciers are found in Antarctica, Argentina, Chile, Canada, Alaska, Greenland and Iceland.

Glacier

Mountain glaciers are widespread, especially in the Andes, the Himalayas, the Rocky Mountains, the Caucasus, Scandinavian mountains, and the Alps.

Glacier

Between 35°N and 35°S, glaciers occur only in the Himalayas, Andes, Rocky Mountains, a few high mountains in East Africa, Mexico, New Guinea and on Zard Kuh in Iran.

Glacier

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

Retreat of glaciers since 1850

The retreat of mountain glaciers, notably in western North America, Asia, the Alps and tropical and subtropical regions of South America, Africa and Indonesia, provide evidence for the rise in global temperatures since the late 19th century.


Global sea level rose about 8 inches in the last century.

Sea level rise

Between 1900 and 2016, the sea level rose by 16–21 cm (6.3–8.3 in).

Sea level rise

In 2019, a study projected that in low emission scenario, sea level will rise 30 centimeters by 2050 and 69 centimetres by 2100, relatively to the level in 2000.

Sea level rise

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

Sea level rise

Since the last glacial maximum about 20,000 years ago, the sea level has risen by more than 125 metres (410 ft), with rates varying from less than a mm/year to 40+ mm/year, as a result of melting ice sheets over Canada and Eurasia.

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).


Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.

Arctic Ocean

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

Arctic ice pack

The September minimum ice extent trend for 1979–2011 declined by 12.0% per decade during 32 years.

Arctic sea ice decline

Observation with satellites show that Arctic sea ice area, extent, and volume have been in decline for a few decades.

Arctic sea ice decline

The amount of multi-year sea ice in the Arctic has declined considerably in recent decades.

Arctic sea ice decline

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


The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950.

Effects of global warming

In Australia, the annual number of hot days (above 35°C) and very hot days (above 40°C) has increased significantly in many areas of the country since 1950.

Effects of global warming

Over most land areas since the 1950s, it is very likely that at all times of year both days and nights have become warmer due to human activities.

New York City

The warmest month on record is July 1999, with a mean temperature of 81.4 °F (27.4 °C).

New York City

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

Physical impacts of climate change

Global surface temperatures in 2016 had increased about 1.0 °C since the 1901.


The U.S. has also witnessed increasing numbers of intense rainfall events.

Hurricane Irma

"Extensive flooding, damage in Turks and Caicos".

Hurricane Irma

Rainfall resulted in several rivers reaching major flood stage.

Hurricane Irma

Heavy precipitation – and storm surge, in some instances – overflowed at least 32 rivers and creeks, causing in significant flooding, particularly along the St. Johns River and its tributaries.

Hurricane Irma

Lee County was lashed by strong winds and heavy rainfall, which caused prolonged flooding in some areas.

Hurricane Irma

In the days after the hurricane, due to the heavy rainfall, numerous rivers had flooded, including residential areas.


Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent.13,14

Carbon dioxide

This has caused an increase in hydrogen ion (acidity) of about 30% since the start of the industrial age through a process known as "ocean acidification."

Human impact on marine life

Ocean acidification has increased 26% since the beginning of the industrial era.

Ocean acidification

In the 15-year period 1995–2010 alone, acidity has increased 6 percent in the upper 100 meters of the Pacific Ocean from Hawaii to Alaska.

Ocean acidification

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

The Sixth Extinction: An Unnatural History:67

Since the beginning of the Industrial Revolution, we have seen increasing levels of carbon dioxide in the atmosphere at an alarming rate.


This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans.

Carbon dioxide

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

Carbon dioxide

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

Global warming

Roughly half of each year's CO2 emissions have been absorbed by plants on land and in oceans.

Greenhouse effect

This increase in radiative forcing from human activity is attributable mainly to increased atmospheric carbon dioxide levels.

Sea

More recently, anthropogenic activities have steadily increased the carbon dioxide content of the atmosphere; about 30–40% of the added CO2 is absorbed by the oceans, forming carbonic acid and lowering the pH (now below 8.1) through a process called ocean acidification.


The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.

Carbon dioxide

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

Carbon dioxide

Carbon dioxide

Oceanic carbon cycle

Current annual increase in atmospheric CO2 is approximately 4 gigatons of carbon.

Oceanic carbon cycle

Carbon dioxide is absorbed from the atmosphere at the ocean's surface at an exchange rate which varies locally but on average, the oceans have a net absorption of CO2 2.2 Pg C per year.


The bushfires in Australia were caused by arsonists and a series of lightning strikes, not 'climate change'.

2007 Kangaroo Island bushfires

The 2007 Kangaroo Island bushfires were a series of bushfires caused by lightning strikes on 6 December 2007 on Kangaroo Island, South Australia, resulting in the destruction of 95,000 hectares (230,000 acres) of national park and wilderness protection area.

2019–20 Australian bushfire season

"Climate change is one factor affecting how fires in Australia burn, regardless of whether arsonists or lightning started them".

Bushfires in Australia

Many fires are as a result of either deliberate arson or carelessness, however these fires normally happen in readily accessible areas and are rapidly brought under control.

Bushfires in Australia

Man-made events include arcing from overhead power lines, arson, accidental ignition in the course of agricultural clearing, grinding and welding activities, campfires, cigarettes and dropped matches, sparks from machinery, and controlled burn escapes.

Bushfires in Australia

The fires would have been caused by both natural phenomenon and human hands.


Discovery Of Massive Volcanic CO2 Emissions Discredits Global Warming Theory.

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).

Paleocene–Eocene Thermal Maximum

Intrusions of hot magma into carbon-rich sediments may have triggered the degassing of isotopically light methane in sufficient volumes to cause global warming and the observed isotope anomaly.

Permian–Triassic extinction event

"Global Warming Led To Atmospheric Hydrogen Sulfide And Permian Extinction".

Permian–Triassic extinction event

The eruptions would also have emitted carbon dioxide, causing global warming.

Permian–Triassic extinction event

The resultant global warming may have caused perhaps the most severe anoxic event in the oceans' history: according to this theory, the oceans became so anoxic, anaerobic sulfur-reducing organisms dominated the chemistry of the oceans and caused massive emissions of toxic hydrogen sulfide.


A series of just-released studies by working-level scientists prove that geological and not atmospheric forces are responsible for melting of Earth’s polar ice sheets.

Climate change in the Arctic

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

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.

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

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.

Retreat of glaciers since 1850

The potential for major sea level rise depends mostly on a significant melting of the polar ice caps of Greenland and Antarctica, as this is where the vast majority of glacial ice is located.


Etna has already put more than 10,000 times the CO2 into the atmosphere than mankind has in our entire time on the Earth.

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

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

Greenhouse gas

According to the report plastic will contribute greenhouse gases in the equivalent of 850 million tonnes of carbon dioxide (CO2) to the atmosphere in 2019.

Greenhouse gas

The pharmaceutical industry emitted 52 megatonnes of Carbon dioxide into the atmosphere in 2015.

Snowball Earth

The carbon dioxide levels necessary to thaw Earth have been estimated as being 350 times what they are today, about 13% of the atmosphere.


More than 500 scientists and professionals in climate and related fields have sent a 'European Climate Declaration' to the Secretary-General of the United Nations.

Scientific consensus on climate change

This scientific opinion is expressed in synthesis reports, by scientific bodies of national or international standing, and by surveys of opinion among climate scientists.

Scientific consensus on climate change:135

Scientific consensus on climate change

European Academy of Sciences and Arts in 2007 issued a formal declaration on climate change titled Let's Be Honest: Human activity is most likely responsible for climate warming.

Scientific consensus on climate change:269

Scientific consensus on climate change

Dennis Bray and Hans von Storch conducted a survey in August 2008 of 2058 climate scientists from 34 different countries.

Sustainability

The Millennium Ecosystem Assessment is an international synthesis by over 1000 of the world's leading biological scientists that analyzes the state of the Earth's ecosystems and provides summaries and guidelines for decision-makers.

Sustainability

It was signed by 15,364 scientists from 184 countries, what made it the letter with the most signatures of scientists in history In November 2019, more than 11,000 scientists from 153 countries published a letter in which they warn about big threats to sustainability from climate change if big changes in policies will not happen.


The consensus among scientists and policy-makers is that we’ll pass this point of no return if the global mean temperature rises by more than two degrees Celsius.

Scientific consensus on climate change:22

Scientific consensus on climate change

"The overall risks of climate change impacts can be reduced by limiting the rate and magnitude of climate change" Without new policies to mitigate climate change, projections suggest an increase in global mean temperature in 2100 of 3.7 to 4.8 °C, relative to pre-industrial levels (median values; the range is 2.5 to 7.8 °C including climate uncertainty).

Scientific consensus on climate change:23

Scientific consensus on climate change

The current trajectory of global greenhouse gas emissions is not consistent with limiting global warming to below 1.5 or 2 °C, relative to pre-industrial levels.

Scientific consensus on climate change:507

Scientific consensus on climate change

Since the start of the 20th century, the global mean surface temperature of the Earth has increased by more than 0.7°C and the rate of warming has been largest in the last 30 years.

Scientific consensus on climate change:719

Scientific consensus on climate change

On the basis of available data, climate scientists are now projecting an average global temperature rise over this century of 2.0 to 4.5°C.

Tipping points in the climate system

The tipping point is difficult to predict, but is estimated to be between 3–4 °C of global temperature rise.


Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Global warming controversy

According to the United States National Research Council, [T]here is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities.

Scientific consensus on climate change:139

Scientific consensus on climate change

European Science Foundation in a 2007 position paper states: 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 ... On-going and increased efforts to mitigate climate change through reduction in greenhouse gases are therefore crucial.

Scientific consensus on climate change:283

Scientific consensus on climate change

Seventy-five of 77 believed that human activity is a significant factor in changing mean global temperatures.

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:692

Scientific consensus on climate change

While ‘climate change’ can be due to natural forces or human activity, there is now substantial evidence to indicate that human activity – and specifically increased greenhouse gas (GHGs) emissions – is a key factor in the pace and extent of global temperature increases.


In no way, shape, or form are humans warming or cooling the planet.

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.

Earth

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

Extinction event

As a result, they are likely to cause the climate to oscillate between cooling and warming, but with an overall trend towards warming as the carbon dioxide they emit can stay in the atmosphere for hundreds of years.

Global cooling

The current scientific consensus on climate change is that the Earth underwent global warming throughout the 20th century and continues to warm.

Volcano

The aerosols increase the Earth's albedo—its reflection of radiation from the Sun back into space—and thus cool the Earth's lower atmosphere or troposphere; however, they also absorb heat radiated up from the Earth, thereby warming the stratosphere.


I think about all the 194 countries that signed onto the Paris accord, the U.S. is the one that's leading the world in reducing emissions.

Paris Agreement

At the conclusion of COP 21 (the 21st meeting of the Conference of the Parties, which guides the Conference), on 12 December 2015, the final wording of the Paris Agreement was adopted by consensus by all of the 195 UNFCCC participating member states and the European Union to reduce emissions as part of the method for reducing greenhouse gas.

Paris Agreement

On 1 April 2016, the United States and China, which together represent almost 40% of global emissions, issued a joint statement confirming that both countries would sign the Paris Climate Agreement.

Paris Agreement

187 states and the EU, representing more than 87% of global greenhouse gas emissions, have ratified or acceded to the Agreement, including China, the United States and India, the countries with three of the four largest greenhouse gas emissions of the UNFCCC members total (about 42% together).

Paris Agreement

The top four emitters (China, USA, EU28 and India) contribute to over 55% of the total emissions over the last decade, excluding emissions from land-use change such as deforestation.

Paris Agreement

The US emits 13% of global emissions and emissions rose 2.5% in 2018.


Based on the increase of solar activity during the twentieth century, it should account for between half to two-thirds of all climate change.

Low-carbon economy

GHG emissions due to anthropogenic (human) activity are the dominant cause of observed global warming (climate change) since the mid-20th century.

Solar activity and climate

In 2000, Lassen and Thejll updated their 1991 research and concluded that while the solar cycle accounted for about half the temperature rise since 1900, it failed to explain a rise of 0.4 °C since 1980.

Solar activity and climate

Under this scenario, they claimed the Sun might have contributed 50% of the observed global warming since 1900.

Solar activity and climate

estimated that the residual effects of the prolonged high solar activity during the last 30 years account for between 16% and 36% of warming from 1950 to 1999.

Solar activity and climate

Their reported relationship appeared to account for nearly 80 per cent of measured temperature changes over this period.


18 proxies tell us the world was the same or warmer 1,000 years ago.

Effects of global warming

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

Hockey stick controversy

Regarding the draft conclusion that the 20th Century was the warmest in the last 1000 years, he said "We don't accept this.

Hockey stick controversy

The SPM statement in the IPCC TAR of 2001 had been that it was "likely that, in the Northern Hemisphere, the 1990s was the warmest decade and 1998 the warmest year" in the past 1,000 years.

Hockey stick controversy

2013 used seafloor and lake bed sediment proxies to reconstruct global temperatures over the past 11,300 years, the last 1,000 years of which confirmed the original MBH99 hockey stick graph.

Holocene extinction

However, the annual mean temperature of the current interglacial period for the last 10,000 years is no higher than that of previous interglacial periods, yet some of the same megafauna survived similar temperature increases.


the Intergovernmental Panel on Climate Change is misleading humanity about climate change and sea levels, and that in fact a new solar-driven cooling period is not far off.

Intergovernmental Panel on Climate Change:157

"Robust findings" of the Synthesis report include: "Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level".

Intergovernmental Panel on Climate Change:160

"Anthropogenic warming and sea level rise would continue for centuries even if GHG emissions were to be reduced sufficiently for GHG concentrations to stabilise, due to the time scales associated with climate processes and feedbacks".

Intergovernmental Panel on Climate Change:293

On the eve of the publication of IPCC's Fourth Assessment Report in 2007 another study was published suggesting that temperatures and sea levels have been rising at or above the maximum rates proposed during IPCC's 2001 Third Assessment Report.

Intergovernmental Panel on Climate Change:295

Over the six years studied, the actual temperature rise was near the top end of the range given by IPCC's 2001 projection, and the actual sea level rise was above the top of the range of the IPCC projection.

Intergovernmental Panel on Climate Change:296

Another example of scientific research which suggests that previous estimates by the IPCC, far from overstating dangers and risks, have actually understated them is a study on projected rises in sea levels.


The human contribution to global warming was about 0.01°C.

Global warming

Current pledges made as part of the Paris Agreement would lead to about 3.0 °C of warming at the end of the 21st century, relative to pre-industrial levels.

Global warming

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

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

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:150

Scientific consensus on climate change

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


So that means that probably about half, maybe half of that nine-tenths of the degree of total warming might be caused by greenhouse gases.

Global warming

Greenhouse gas

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

Patrick Michaels

In 2018, Michaels asserted on Fox News, "probably about half, maybe half of that nine-tenths of the degree [of total warming] might be caused by greenhouse gases."

Scientific consensus on climate change

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.


NASA has been adjusting temperatures from the past[...]

Global warming

"Estimating Changes in Global Temperature since the Preindustrial Period".

International Space Station

During various station activities and crew rest times, the lights in the ISS can be dimmed, switched off, and color temperatures adjusted.

NASA

On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: Play media It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge [Sputnik] be met by an energetic program of research and development for the conquest of space ...

NASA

""2016 Climate Trends Continue to Break Records".

Space Shuttle Challenger disaster

Tests and adjusted calculations later confirmed that the temperature of the joint was not substantially different from the ambient temperature.


New Study Confirms EVs Considerably Worse For Climate Than Diesel Cars.

Car

As of 2018[update] the average diesel car has a worse effect on air quality than the average gasoline car But both gasoline and diesel cars pollute more than electric cars.While there are different ways to power cars most rely on gasoline or diesel, and they consume almost a quarter of world oil production as of 2019[update].

Car

"EEA report confirms: electric cars are better for climate and air quality".

Electric vehicle

A study by Cambridge Econometrics shows the potential air pollution benefits of EVs.

Electric vehicle

However, looking at the well-to-wheel efficiency of EVs, their total emissions, while still lower, are closer to an efficient gasoline or diesel in most countries where electricity generation relies on fossil fuels.

Electric vehicle

The lifecycle analysis of EVs shows that even when powered by the most carbon intensive electricity in Europe, they emit less greenhouse gases than a conventional diesel vehicle.


the concentration of carbon dioxide in Earth’s atmosphere has climbed to a level last seen more than 3 million years ago — before humans even appeared on the rocky ball we call home.

Carbon dioxide in Earth's atmosphere

The daily average concentration of atmospheric CO 2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 although this concentration had already been reached in the Arctic in June 2012.

Carbon dioxide in Earth's atmosphere

The National Geographic wrote that the concentration of carbon dioxide in the atmosphere is this high "for the first time in 55 years of measurement—and probably more than 3 million years of Earth history."

Carbon dioxide in Earth's atmosphere

The current concentration may be the highest in the last 20 million years.

Carbon dioxide in Earth's atmosphere

About 34 million years ago, the time of the Eocene–Oligocene extinction event and when the Antarctic ice sheet started to take its current form, CO 2 was about 760 ppm, and there is geochemical evidence that concentrations were less than 300 ppm by about 20 million years ago.

Carbon dioxide

Combustion of fossil fuels and deforestation have caused the atmospheric concentration of carbon dioxide to increase by about 43% since the beginning of the age of industrialization.


Sea level rise due to climate change is not going to happen.

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.

Kiribati

The United Nations Intergovernmental Panel on Climate Change predicts that sea levels will rise by about 50 cm (20 in) by 2100 due to global warming and a further rise would be inevitable.

Sea level rise

In September 2019 the Intergovernmental Panel on Climate Change published a report about the impact of climate change on the oceans including sea level rise.

Sea level rise

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

Sea level rise

"The Oceans We Know Won't Survive Climate Change".


The models predicted about three times the amount of warming in the world we’ve seen since 1988.

Global warming controversy

Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100.

Global warming

Models not only project different future temperature with different emissions of greenhouse gases, but also do not fully agree on the strength of different feedbacks on climate sensitivity and the amount of inertia of the system.

Global warming

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

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

Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) in a moderate scenario, or as much as 2.6 to 4.8 °C (4.7 to 8.6 °F) in an extreme scenario, depending on the rate of future greenhouse gas emissions and on climate feedback effects.


carbon dioxide has had a minuscule effect on global climate.

Carbon dioxide

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

Carbon dioxide

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

Carbon dioxide

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

Fossil fuel

Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming along with ocean acidification.

Greenhouse effect

The effect of combustion-produced carbon dioxide on the global climate, a special case of the greenhouse effect first described in 1896 by Svante Arrhenius, has also been called the Callendar effect.


Sea-level rise does not seem to depend on ocean temperature, and certainly not on CO2.

Paleocene–Eocene Thermal Maximum

This depth depends on (among other things) temperature and the amount of CO 2 dissolved in the ocean.

Sea level rise

The Atlantic is set to warm at a faster pace than the Pacific.

Sea level rise

Sea level rise

The heat needed to raise an average temperature increase of the entire world ocean by 0.01 °C would increase the atmospheric temperature by approximately 10 °C.

Sea level rise

Thus, a small change in the mean temperature of the ocean represents a very large change in the total heat content of the climate system.


unadjusted data suggests that temperatures in Australia have only increased by 0.3 degrees over the past century, not the 1 degree usually claimed.

Australia

"Australia's extreme heat is sign of things to come, scientists warn".

Australia

According to the Bureau of Meteorology's 2011 Australian Climate Statement, Australia had lower than average temperatures in 2011 as a consequence of a La Niña weather pattern; however, "the country's 10-year average continues to demonstrate the rising trend in temperatures, with 2002–2011 likely to rank in the top two warmest 10-year periods on record for Australia, at 0.52 °C (0.94 °F) above the long-term average".

Australia

Furthermore, 2014 was Australia's third warmest year since national temperature observations commenced in 1910.

Australia

January 2019 was the hottest month ever in Australia with average temperatures exceeding 30 °C (86 °F).

Australia

Australia has grown at an average annual rate of 3.6% for over 15 years, in comparison to the OECD annual average of 2.5%.


climate models have overestimated the amount of global warming and failed to predict what climatologists call the warming ‘hiatus’.

Climate

These models predict an upward trend in the global mean surface temperature, with the most rapid increase in temperature being projected for the higher latitudes of the Northern Hemisphere.

Climatology

These models predict an upward trend in the surface temperatures, as well as a more rapid increase in temperature at higher latitudes.

Global warming

Uncertainty over feedbacks is the major reason why different climate models project different magnitudes of warming for a given amount of emissions.

Global warming

The 2017 United States-published National Climate Assessment notes that "climate models may still be underestimating or missing relevant feedback processes".

Global warming

Additional disputes concern estimates of climate sensitivity, predictions of additional warming, what the consequences of global warming will be, and what to do about it.


Climate scientists say that aspects of the case of Hurricane Harvey suggest global warming is making a bad situation worse.

Effects of global warming

The effects of climate change, in combination with the sustained increases in greenhouse gas emissions, have led scientists to characterize it as a climate emergency.

Hurricane Harvey

"It's a fact: climate change made Hurricane Harvey more deadly".

Hurricane Harvey

The Gulf of Mexico is known for hurricanes in August, so their incidence alone cannot be attributed to global warming, but the warming climate does influence certain attributes of storms.

Hurricane Harvey

Weather events are due to multiple factors, and so cannot be said to be caused by one precondition, but climate change affects aspects of extreme events, and very likely worsened some of the impacts of Harvey.

Hurricane Harvey

"Storm Harvey: impacts likely worsened due to global warming".


according, again, to the official figures—during this past 10 years, if anything, mean global temperature, average world temperature, has slightly declined.

2000s (decade)

The global temperature kept climbing during the decade.

Global warming

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

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

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

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.


Most likely the primary control knob on climate change is the ocean waters and this environment that we live in.

Climate change (general concept)

These include processes such as variations in solar radiation, variations in the Earth's orbit, variations in the albedo or reflectivity of the continents, atmosphere, and oceans, mountain-building and continental drift and changes in greenhouse gas concentrations.

Climate change (general concept)

"Episodic fresh surface waters in the Eocene Arctic Ocean".

Climate change and ecosystems

Alterations to the ocean currents, due to increased freshwater inputs from glacier melt, and the potential alterations to thermohaline circulation of the worlds oceans, may affect existing fisheries upon which humans depend as well.

Climate change denial

United States Secretary of Energy Rick Perry, in a 19 June 2017 interview with CNBC, acknowledged the existence of climate change and impact from humans, but said that he did not agree with the idea that carbon dioxide was the primary driver of global warming pointing instead to "the ocean waters and this environment that we live in".

Mediterranean Sea

Because of the short residence time of waters, the Mediterranean Sea is considered a hot-spot for climate change effects.


Global warming' is a myth — so say 80 graphs from 58 peer-reviewed scientific papers published in 2017.

Climatic Research Unit email controversy:84

The Independent Climate Change Email Review report was published on 7 July 2010.

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 controversy

The highly publicised figures came from work still undergoing peer review, and CICERO would wait until they had been published in a journal before disseminating the results.

Global warming

His 1861 paper proposed changing concentrations of these gases could have caused "all the mutations of climate which the researches of geologists reveal" and would explain ice age changes.

Global warming

Müller 2010; The New York Times, 25 May 2015; UNFCCC: Copenhagen 2009. openDemocracy, 12 January 2010; EUobserver, 20 December 2009.


global warming ceased around the end of the twentieth century and was followed (since 1997) by 19 years of stable temperature.

20th century

The 20th (twentieth) century was a century that began on January 1, 1901 and ended on December 31, 2000.

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

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

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.


Doubling the concentration of atmospheric CO2 from its pre-industrial level, in the absence of other forcings and feedbacks, would likely cause a warming of ~0.3°C to 1.1°C.

Climate change feedback

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

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

Neglecting other forcings and considering the temperature increase to be an equilibrium increase would lead to a sensitivity of about 1.1 °C (2.0 °F).

Global warming

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

Permian–Triassic extinction event

Further evidence for environmental change around the P–Tr boundary suggests an 8 °C (14 °F) rise in temperature, and an increase in CO 2 levels by 2000 ppm (for comparison, the concentration immediately before the industrial revolution was 280 ppm, and the amount today is about 410 ppm).


more than 100 per cent of the warming over the past century is due to human actions.

Kyoto Protocol

The view that human activities are likely responsible for most of the observed increase in global mean temperature ("global warming") since the mid-20th century is an accurate reflection of current scientific thinking.

Scientific consensus on climate change

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

Scientific consensus on climate change

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

Scientific consensus on climate change:69

Scientific consensus on climate change

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

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.


I would not agree that carbon dioxide is a primary contributor to the global warming that we see.

Greenhouse gas

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

Scientific consensus on climate change

Scott Pruitt

On March 9, 2017, in an interview on CNBC's Squawk Box, Pruitt stated that he "would not agree that" carbon dioxide is "a primary contributor to the global warming that we see" backing up his claim by stating that "measuring with precision human activity on the climate is something very challenging to do and there's tremendous disagreement about the degree of impact."

Scott Pruitt

In March 2017, Pruitt said that he does not believe that human activities, specifically carbon dioxide emissions, are a primary contributor to climate change, a view which is in contradiction with the scientific consensus.

Scott Pruitt

Pruitt rejects the scientific consensus that human-caused carbon dioxide emissions are a primary contributor to climate change.


no one really knows if last year 2016 was a global temperature record.

Global warming

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

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.

Ice age

This allows a temperature record to be constructed.

James Hansen

But we know the last time the world was 2 degrees warmer, sea level was 6 meters or 20 feet higher."

James Hansen

"Breaking global temperature records after Mt.


the U.S. is shattering high temperature records far more frequently than it is shattering low temperature records.

Georgia (U.S. state)

The highest temperature ever recorded is 112 °F (44.4 °C) in Louisville on July 24, 1952, while the lowest is −17 °F (−27.2 °C) in northern Floyd County on January 27, 1940.

Ice core

At lower temperatures, the difference is more pronounced.

San Francisco

The lowest recorded temperature was 27 °F (−3 °C) on December 11, 1932.

U.S. state and territory temperature extremes:0

The following table lists the highest and lowest temperatures recorded in the 50 U.S. states, the District of Columbia, and the 5 inhabited U.S. territories during the past two centuries, in both Fahrenheit and Celsius.

U.S. state and territory temperature extremes:2

record low of 40°F in 1911 in Aibonito and 1966 in San Sebastian in Puerto Rico), only the most recent date is shown.


Global warming

Global warming

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

Scientific consensus on climate change:134

Scientific consensus on climate change

A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change.

Scientific consensus on climate change:5

Scientific consensus on climate change

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

Scientific consensus on climate change:653

Scientific consensus on climate change

AIBS Position Statements "Observations throughout the world make it clear that climate change is occurring, and rigorous scientific research demonstrates that the greenhouse gases emitted by human activities are the primary driver."


The Earth’s climate is changing in response to increasing concentrations of greenhouse gases (GHGs) and particulate matter in the atmosphere, largely as the result of human activities.

Climate

The most talked-about applications of these models in recent years have been their use to infer the consequences of increasing greenhouse gases in the atmosphere, primarily carbon dioxide (see greenhouse gas).

Earth

Water vapor, carbon dioxide, methane, nitrous oxide, and ozone are the primary greenhouse gases in the atmosphere.

Global warming

increased concentrations of greenhouse gases), solar luminosity, volcanic eruptions, and variations in the Earth's orbit around the Sun.

Global warming

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.


Research has found a human influence on the climate of the past several decades ...

Attribution of recent climate change

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

Attribution of recent climate change

Like the warming "signal" that has gradually emerged from the "noise" of natural climate variability, the scientific evidence for a human influence on global climate has accumulated over the past several decades, from many hundreds of studies.

Scientific consensus on climate change:117

Scientific consensus on climate change

This report explicitly endorses the IPCC view of attribution of recent climate change as representing the view of the scientific community: The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes is also a reflection of natural variability.

Scientific consensus on climate change:18

Scientific consensus on climate change

Human influence on the climate system is clear.

Scientific consensus on climate change:723

Scientific consensus on climate change

The available evidence suggests very strongly that human activities have already begun to make significant changes to the earth's climate, and that the long-term risk of delaying action is greater than the cost of avoiding/minimising the risk."


The IPCC (2013), USGCRP (2017), and USGCRP (2018) indicate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-twentieth century.

Global warming

The scientific consensus as of 2013[update], as stated in the IPCC Fifth Assessment Report, is that it "is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century".

Global warming

The Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report concluded, "It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century".

Intergovernmental Panel on Climate Change:127

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

Intergovernmental Panel on Climate Change: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:37

Scientific consensus on climate change

These, together with other anthropogenic drivers, are "extremely likely" (where that means more than 95% probability) to have been the dominant cause of the observed global warming since the mid-20th century.


Earth's changing climate is a critical issue and poses the risk of significant environmental, social and economic disruptions around the globe.

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

A 2013 study found that significant climatic changes were associated with a higher risk of conflict worldwide, and predicted that "amplified rates of human conflict could represent a large and critical social impact of anthropogenic climate change in both low- and high-income countries."

Global catastrophic risk

Climate change refers to a lasting change in the Earth's climate.

Scientific consensus on climate change:569

Scientific consensus on climate change

If no mitigating actions are taken, significant disruptions in the Earth's physical and ecological systems, social systems, security and human health are likely to occur.

Sustainability

Analysis of consumption patterns relates resource use to the environmental, social and economic impacts at the scale or context under investigation.


Human activities (mainly greenhouse-gas emissions) are the dominant cause of the rapid warming since the middle 1900s (IPCC, 2013).

Global warming

Over the last three decades of the twentieth century, gross domestic product per capita and population growth were the main drivers of increases in greenhouse gas emissions.

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

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:187

Scientific consensus on climate change

The dominant cause of the warming since the 1950s is human activities.

Scientific consensus on climate change

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


Scientists have known for some time, from multiple lines of evidence, that humans are changing Earth’s climate, primarily through greenhouse gas emissions.

Global warming

Global warming

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

Scientific consensus on climate change:459

Scientific consensus on climate change

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

Scientific consensus on climate change

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

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.


Earth’s climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities.

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.

Nature

"Tropical Ocean Warming Drives Recent Northern Hemisphere Climate Change".

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:50

Scientific consensus on climate change

Most of the global warming since the mid-20th century is very likely due to human activities.

Scientific consensus on climate change:565

Scientific consensus on climate change

American Physical Society Climate Change Policy Statement, November 2007 "Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate.


Global issue

Global warming

IPCC AR5 WG1 Summary for Policymakers 2013, p. 4: Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.

Global warming

While there have been prehistoric periods of global warming, many observed changes since the mid-20th century have been unprecedented over decades to millennia.

Intergovernmental Panel on Climate Change:187

Conclusions of AR5 are summarized below: Working Group I "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia".

Scientific consensus on climate change:16

Scientific consensus on climate change

Its conclusions are summarized below: "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia."


The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.

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

Further examples include sea level rise, widespread melting of snow and land ice, increased heat content of the oceans, increased humidity, and the earlier timing of spring events, such as the flowering of plants.

Global warming

The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased "Myths vs. Facts: Denial of Petitions for Reconsideration of the Endangerment and Cause or Contribute Findings for Greenhouse Gases under Section 202(a) of the Clean Air Act".

Scientific consensus on climate change:391

Scientific consensus on climate change

"Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level."

Scientific consensus on climate change:49

Scientific consensus on climate change

The IPCC Fourth Assessment Report stated that: Warming of the climate system is unequivocal, as evidenced by increases in global average air and ocean temperatures, the widespread melting of snow and ice, and rising global average sea level.


CLOUD experiment

The primary goal is to understand the influence of galactic cosmic rays (GCRs) on aerosols and clouds, and their implications for climate.

Climate change (general concept)

It has been postulated that ionized particles known as cosmic rays could impact cloud cover and thereby the climate.

Henrik Svensmark

He is known for his theory on the effects of cosmic rays on cloud formation as an indirect cause of global warming.

Henrik Svensmark

"Cosmic rays blamed for global warming".

Henrik Svensmark

They also found that galactic cosmic rays, and total solar irradiance did not have any statistically significant influence on changes in cloud cover.


Sea level rise due to global warming is exaggerated.

Global warming

Sea level rise

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

Sea level rise

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

Under the influence of global warming, melt at the base of the ice sheet increases.

Sea level

However, 20th century and current millennium sea level rise is presumed to be caused by global warming, and careful measurement of variations in MSL can offer insights into ongoing climate change.


Medieval Warm Period was warmer than the climate warming today.

Medieval Warm Period

The Medieval Warm Period (MWP) also known as the Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region lasting from c. 950 to c. 1250.

Medieval Warm Period

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

Medieval Warm Period

Much of the Northern Hemisphere showed significant cooling during the Little Ice Age (defined in the study from 1400 to 1700), but Labrador and isolated parts of the United States appeared to be approximately as warm as during the 1961–1990 period.

Medieval Warm Period

It is thought that between c. 950 and c. 1100 was the Northern Hemisphere's warmest period since the Roman Warm Period.

Medieval Warm Period

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


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 current Arctic warming is leading to ancient carbon being released from thawing permafrost, leading to methane and carbon dioxide production by micro-organisms.


Increasing CO2 in the atmosphere has little to no effect.

Carbon dioxide

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

Carbon dioxide

Conversely, a rise in the partial pressure of CO 2 or a lower pH will cause offloading of oxygen from hemoglobin, which is known as the Bohr effect.

Global warming

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

Global warming

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

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.


Human CO2 is a tiny fraction of CO2 emissions.

Carbon dioxide

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

Carbon dioxide

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

Greenhouse gas

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

Greenhouse gas

Land use change (mainly deforestation in the tropics) account for up to one third of total anthropogenic CO 2 emissions.

Greenhouse gas

The estimate of total CO 2 emissions includes biotic carbon emissions, mainly from deforestation.


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.