Evolution of Climate Models

Mid 1970s
Early climate models were limited. They only included carbon dioxide, heat from the sun (radiation) and rain, but not clouds.




Mid 1980s
Clouds, land surface and ice were added into the mix in the 1980s. Different types of land behave differently; deserts and ice are more likely to reflect radiation, and forests are more likely to absorb it.




1990 - IPCC’s first report
A simple model of the oceans now joins the picture, as the first IPCC report comes out. To begin with, only the top layer of the sea was modelled.




1996 Second Assessment Report
More sophisticated models of the ocean are added. Volcanoes are also shown. Their eruptions throw particles into the atmosphere, which can block sunlight and temporarily reduce global temperatures.




2001 Third Assessment Report
By bringing the carbon cycle into the picture, the different ways C02 is stored and released into the atmosphere gives greater realism to climate models. Understanding of the oceans is deepened.




2007 Fourth Assessment Report
Chemical reactions in the atmosphere join the climate models; they are now produced using computing power 256 times more powerful than that available in the 1970s.