Consensus about global warming

There is a significant scientific consensus about global warming; specifically that humans are causing the widespread warming on the Earth. It was found that at least 97% of expert climate scientists agree with this claim,[1] thus forming a dominant scientific consensus within the community. In addition, most of the leading scientific organizations worldwide have openly expressed their support for this claim, such as the IPCC.[2] Click here to see a list of these scientific organizations.

The importance of this consensus is often underestimated by the public. This is due in part to the spreading of misinformation by climate change deniers, as well as a misunderstanding of how climate scientists came to these conclusions. The trust that people place upon experts in other fields, such as doctors, is much higher than is placed upon climate experts mostly due to this misinformation; only 16% of Americans realize the consensus is over 90%.[3]

Reasons for consensus

There are many reasons that explain why the majority of the scientific community agrees on humanity's effect on climate change. Many of which are covered on this website:

  1. Anthropogenic carbon emissions have increased drastically in the past century, adding an imbalance to the natural carbon cycle.
  2. Carbon dioxide is a greenhouse gas, therefore contributing to the greenhouse effect. Along with the emissions of other greenhouse gases, it is causing a warming effect that has been measured in great detail.[4]
  3. This warming effect causes measurable effects: Rising sea levels are already noticeable as would be expected of a warming world, heat waves are more prominent, Arctic sea ice is melting, glaciers are retreating, the oceans are acidifying, among others.

When substantial evidence piles up in favor of a hypothesis, it becomes increasingly difficult to outright dismiss it. It also becomes much easier to take a stand in favor of the hypothesis. This is the case for human-induced global warming, as scientists can recognize as objectively as possible that global warming is in fact being caused by humans. It isn't just increasing temperatures that scientists can agree on, as the following table shows the likelihood of various phenomena occurring into the future.

Table 1. Likelihood of various climate change phenomena in the 21st century.[5]
Phenomena and direction of trend Likelihood of humans contributing Likelihood of further changes into the late 21st century
Warmer and/or fewer cold days and nights over most land areas Very likely Virtually certain
Warmer and/or more frequent hot days and nights over most land areas Very likely Virtually certain
Heat waves; frequency and/or duration increases over most land areas Likely Very likely
Heavy precipitation events; increase in the frequency, intensity, and/or amount of heavy precipitation Medium confidence Very likely over most of the mid-latitude land masses and over wet tropical regions
Increase in intensity and/or duration of drought Medium confidence Likely on a regional to global scale
Increases in intense tropical cycle activity Low confidence More likely than not (in the Western North Pacific and North Atlantic)
Increased incidence and/or magnitude of extreme high sea level Likely Very likely

The video below is an explanation by lead author of the consensus study, explaining methods of determining the consensus, as well as its importance.


  1. J. Cook, N. Oreskes, P. Doran, W. Anderegg, B. Verheggen, E. Maibach, and J. Carlton. Consensus on consensus: a synthesis of consensus estimates on human-caused global warming [Online], Available:
  2. NASA. (accessed May 24, 2016). Scientific consensus: Earth's climate is warming [Online], Available:
  3. Skeptical Science. (Accessed May 30, 2016). The 97% consensus on global warming [Online], Available:
  4. NASA. (Accessed May 24, 2016). Global Temperature [Online], Available:
  5. IPCC. AR5 Summary for Policy Makers [Online], Available:

Authors and Editors

Jordan Hanania, Jason Donev
Last updated: September 17, 2016
Get Citation