Climate models

Climate models

Forecast increase in temperature of several scenarios stability (colored ribbons) based on the report to the Fourth IPCC view. Black line shows the best forecasting; red and blue lines show the limits of possibility that can happen.
Calculation of global warming in 2001 from several climate models based on the SRES A2 scenario, which assumes no action is taken to reduce the main emisi.Artikel for this section are: global climate model
Scientists have studied global warming based on computer models based on the basic principles of fluid dinamikan, radiation transfer, and other processes, with some simplifications due to the limited computer capabilities. These models predict that the addition of gases to the greenhouse effect and warmer climate. [23] Although the assumptions used are similar to the concentration of greenhouse gases in the future, the climate sensitivity would still be in a certain range.

By inserting the elements of uncertainty to the concentration of greenhouse gases and climate modeling, the IPCC estimates that warming of about 1.1 ° C to 6.4 ° C (2.0 ° F to 11.5 ° F) between 1990 and 2100. [1] climate models are also used to investigate the causes of climate change is happening right now by comparing the observed changes with the results of the model predictions to various causes, both natural and human activities.

Current climate models produce a fairly good resemblance with the global temperature changes observed during the last hundred years, but did not simulate all aspects of the climate. [24] These models are not exactly state that the warming occurred between 1910 and 1945 caused by natural processes or human activities; but they show that the warming since 1975 is dominated by the emission of gases that humans produce.

Most climate models, when calculating the future climate, based on scenarios of greenhouse gases, usually from the Special Report on Emission Scenarios (Special Report on Emissions Scenarios / SRES) IPCC. Which is rarely done, the model calculated by adding a simulation of the carbon cycle; that usually produces positive feedback, although the response is uncertain (for the A2 SRES scenario, responses vary between 20 and addition of 200 ppm CO2). Several studies also show some positive feedback. [25] [26] [27]

The influence of clouds is also one source of uncertainty to the models produced today, although now there has been progress in resolving this issue. [28] We also occur the discussions were still ongoing as to whether climate models exclude the effects of feedback and not directly from the variation of the Sun.