Katana VentraIP

Scientific consensus on climate change

There is a nearly unanimous scientific consensus that the Earth has been consistently warming since the start of the Industrial Revolution, that the rate of recent warming is largely unprecedented,[1]: 8 [2]: 11  and that this warming is mainly the result of a rapid increase in atmospheric carbon dioxide (CO2) caused by human activities. The human activities causing this warming include fossil fuel combustion, cement production, and land use changes such as deforestation,[3]: 10–11  with a significant supporting role from the other greenhouse gases such as methane and nitrous oxide.[1]: 7  This human role in climate change is considered "unequivocal" and "incontrovertible".[1]: 4 [2]: 4 

Nearly all actively publishing climate scientists say humans are causing climate change.[4][5] Surveys of the scientific literature are another way to measure scientific consensus. A 2019 review of scientific papers found the consensus on the cause of climate change to be at 100%,[6] and a 2021 study concluded that over 99% of scientific papers agree on the human cause of climate change.[7] The small percentage of papers that disagreed with the consensus often contained errors or could not be replicated.[8]


The evidence for global warming due to human influence has been recognized by the national science academies of all the major industrialized countries.[9] In the scientific literature, there is a very strong consensus that global surface temperatures have increased in recent decades and that the trend is caused by human-induced emissions of greenhouse gases.[10] No scientific body of national or international standing disagrees with this view.[11] A few organizations with members in extractive industries hold non-committal positions,[12] and some have tried to persuade the public that climate change is not happening, or if the climate is changing it is not because of human influence,[13][14] attempting to sow doubt in the scientific consensus.[15]

It is "unequivocal" and "incontrovertible" that the from human activities have caused warming on land, in oceans and in the troposphere. There are no natural processes which can provide an alternate explanation.[1]: 4 [2]: 4 

greenhouse gas emissions

The atmospheric levels of are the highest they have been in at least 2 million years,[1]: 8  if not 3.2 million years.[2]: 11  The atmospheric levels of two other major greenhouse gases, methane and nitrous oxide, are the highest they have been in at least the past 800,000 years. The record of the past 800,000 years also shows that the increases in their concentrations seen since 1750 would take millennia to be caused by natural processes.[1]: 8 

carbon dioxide

The decade of has been 1.1 °C (2.0 °F) warmer than the late 19th century, and the warmest since the start of a consistent instrumental temperature record.[1]: 5 [2]: 4  The warming of the past 50 years has occurred faster than any other warming over the past 2,000 years, if not longer.[1]: 8 [2]: 11 

2010s

appears to have been increasing since 1950, but the rainfall patterns have also been shifting, and there is more evidence for increases in heavy precipitation which causes flash floods.[1]: 5, 9 [2]: 10, 18 

Precipitation

Global sea level has increased by 20–25 cm (8–10 in) since 1900, with half of that increase occurring since 1980. This has been the fastest in "at least the last 3000 years", which is very likely to have been caused by human activity.[1]: 5, 8 [2]: 4 

sea level rise

As the recent warming , its water expands in volume. This causes half of the recent sea level rise, with the rest due to the warming melting the ice sheets and glaciers.[1]: 11 [2]: 35 

heats the ocean

While there have always been such as tropical cyclones, droughts, heat waves, and rainfall extremes, climate change has made many of them more severe, more frequent, or more likely to co-occur, in every part of the globe.[1]: 8–9, 15–16 [2]: 4 

extreme weather events

The dangers of extreme weather events will continue increasing unless there is a rapid decrease in greenhouse gas emissions needed to curb further warming.: 15 [2]: 33 

[1]

Increased warming will lead to worse impacts.: 15 [2]: 21 

[1]

The extent of human-caused emissions will be the main cause of future warming.: 13, 15 [2]: 35 

[1]

The current scientific consensus regarding causes and mechanisms of climate change, its effects and what should be done about it (climate action) is that:

Climate change denial

History of climate change science

List of climate change controversies

List of climate scientists

World Scientists' Warning to Humanity