Category:Feedback Factors and Radiative Forcing

From ClimateWiki

According to the Intergovernmental Panel on Climate Change (IPCC), “the combined radiative forcing due to increases in carbon dioxide, methane, and nitrous oxide is +2.30 [+2.07 to +2.35] W m-2, and its rate of increase during the industrial era is very likely to have been unprecedented in more than 10,000 years [italics in the original]” (IPCC, 2007-I, p. 3). The IPCC calculates that this sensitivity of earth’s climate system to greenhouse gases (GHG) means that if CO2 concentrations were to double, the rise in global average surface temperature “is likely to be in the range 2°C to 4.5°C with a best estimate of about 3°C, and is very unlikely to be less than 1.5°C [italics in the original]” (Ibid., p. 12).

Many scientific studies suggest this model-derived sensitivity is too large and feedbacks in the climate system reduce it to values that are an order of magnitude smaller. This chapter reviews those feedbacks most often mentioned in the scientific literature, some of which have the ability to totally offset the radiative forcing expected from the rise in atmospheric CO2.

Additional information on this topic, including reviews of feedback factors not discussed here, can be found at http://www.co2science.org/subject/f/subject _f.php under the heading Feedback Factors.

The following pages are taken from Climate Change Reconsidered and can be used as a guide to get you through the basics of this category:

Aerosols

Carbonyl Sulfide

Clouds

Diffuse Light

Dimethyl sulfide

Iodocompounds

Methane

Nitrous oxide

References

IPCC. 2007-I. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller. (Eds.) Cambridge University Press, Cambridge, UK.