Enter a term in the search box to find its definition.
Settings
Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).
Term Lookup
Settings
All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.
The percentage contribution to global warming over the past 50-75 years is shown in two categories, human causes (left) and natural causes (right), from various peer-reviewed studies (colors). The studies used a wide range of independent methods, and provide multiple lines of evidence that humans are by far the dominant cause of recent global warming. Most studies showed that recent natural contributions have been zero or slightly in the cooling direction, thereby masking part of the human contribution and in some cases causing it to exceed 100% of the total warming.