Due to the growing greenhouse gas content in the atmosphere, a noticable increase in the global mean air temperature is very likely for the decades to come. All climate models computed worldwide for various possible increases in greenhouse gas concentrations with respect to the Fourth IPCC Assessment Report (IPCC AR4, published in 2007), show a rise in the global mean temperature. The simulated temperature change for the next 100 years, based on the mean result of the approximately 20 IPCC AR4 simulations worldwide, indicates a pronounced warming over the continents compared with the moderate warming in maritime regions.
For the Scenario A1B - not the most pessimistic, but also not the most optimistic scenario - it is expected that the global mean temperature change could get around 3 degrees compared with the situation at the end of last century within the next 100 years.