The **climate sensitivity** is the increase in temperature that would be caused by doubling the concentration of CO₂ in the Earth's atmosphere. The [[IPCC]] currently estimates a range of 2 to 4.5 °C for the overall climate sensitivity. See: * IPCC AR4 Working Group I, [Section 8.6](http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter8.pdf#page=41). for model estimates and * IPCC AR4 Working Group I, [Section 9.6](http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter9.pdf). for observational estimates. ## References ## An excellent review article on climate sensitivity is: * Reto Knutti and Gabriele C. Hegerl, [The equilibrium sensitivity of the Earth's temperature to radiation changes](http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf), _[Nature Geoscience](http://www.iac.ethz.ch/people/knuttir/papers/knutti08natgeo.pdf)_ **1** (2008), 735--748. Also see: * J.D. Annan and J.C. Hargreaves, [On the generation and interpretation of probabilistic estimates of climate sensitivity](http://www.jamstec.go.jp/frsgc/research/d5/jdannan/probrevised.pdf), 2009. For nonlinear aspects of climate sensitivity, see: * I. Zaliapin and M. Ghil, [Another look at climate sensitivity](http://www.nonlin-processes-geophys.net/17/113/2010/npg-17-113-2010.pdf), _[Nonlinear Processes in Geophysics](http://www.nonlin-processes-geophys.net/17/113/2010/npg-17-113-2010.pdf) **16** (2010), 113-122. category:climate [[!redirects climate sensitivity]]