About the fact sheet
- Climate sensitivity is one of the key measures used in climate modelling. Climate sensitivity describes the amount of warming in the atmosphere associated with increases in atmospheric carbon dioxide (CO2).
- The climate sensitivity is provided as a range of estimates due to underlying uncertainty in the behaviour of some aspects of the climate system as the planet warms.
- The IPCC Fifth Assessment Report (AR5) has slightly revised the climate sensitivity estimates from the IPCC Fourth Assessment Report in 2007. However the range of estimates has been broadly consistent across three IPCC reports over the past 12 years.
- The AR5 expresses stronger confidence in some fundamental processes in models that determine climate sensitivity (such as the response of water vapour) than the Fourth Assessment Report.
- The latest projections for global warming scenarios for the end of this century are comparable to corresponding results from the Fourth Assessment Report in 2007.