Query: the models predicted seven times as much warming as has been observed

Relevant passages:
Scientific consensus on climate change <=SEP=> There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports.  Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors.

Deforestation <=SEP=> Deforestation , clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use . Examples of deforestation include conversion of forestland to farms , ranches , or urban use . The most concentrated deforestation occurs in tropical rainforests . About 30 % of Earth 's land surface is covered by forests .   Deforestation occurs for multiple reasons : trees are cut down to be used for building or sold as fuel , ( sometimes in the form of charcoal or timber ) , while cleared land is used as pasture for livestock and plantation . The removal of trees without sufficient reforestation has resulted in damage to habitat , biodiversity loss and aridity . It has adverse impacts on biosequestration of atmospheric carbon dioxide . Deforestation has also been used in war to deprive the enemy of vital resources and cover for its forces . Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency and the United States military in Vietnam during the Vietnam War . As of 2005 , net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$ 4,600 . Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland .   Disregard of ascribed value , lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale . In many countries , deforestation , both naturally occurring and human-induced , is an ongoing issue . Deforestation causes extinction , changes to climatic conditions , desertification , and displacement of populations as observed by current conditions and in the past through the fossil record . More than half of all plant and land animal species in the world live in tropical forests .   Between 2000 and 2012 , 2.3 e6sqkm of forests around the world were cut down . As a result of deforestation , only 6.2 e6km2 remain of the original 16 e6km2 of forest that formerly covered the Earth .

James Hansen <=SEP=> James Edward Hansen ( born 29 March 1941 ) is an American adjunct professor in the Department of Earth and Environmental Sciences at Columbia University . He is best known for his research in climatology , his 1988 Congressional testimony on climate change that helped raise broad awareness of global warming , and his advocacy of action to avoid dangerous climate change . In recent years he has become a climate activist to mitigate the effects of climate change , on a few occasions leading to his arrest .   In 2000 , Hansen advanced an alternative view of global warming over the last 100 years , arguing that during that time frame the negative forcing via aerosols and the positive forcing via largely balanced each other out , and that the 0.74 ± 0.18 ° C net rise in average global temperatures could mostly be explained by greenhouse gases other than carbon dioxide , such as methane and chlorofluorocarbons . However , even then he wrote `` the future balance of forcings is likely to shift toward dominance of CO2 over aerosols ''

General circulation model <=SEP=> A general circulation model ( GCM ) is a type of climate model . It employs a mathematical model of the general circulation of a planetary atmosphere or ocean . It uses the Navier -- Stokes equations on a rotating sphere with thermodynamic terms for various energy sources ( radiation , latent heat ) . These equations are the basis for computer programs used to simulate the Earth 's atmosphere or oceans . Atmospheric and oceanic GCMs ( AGCM and OGCM ) are key components along with sea ice and land-surface components .   GCMs and global climate models are used for weather forecasting , understanding the climate and forecasting climate change .   Versions designed for decade to century time scale climate applications were originally created by Syukuro Manabe and Kirk Bryan at the Geophysical Fluid Dynamics Laboratory in Princeton , New Jersey . These models are based on the integration of a variety of fluid dynamical , chemical and sometimes biological equations .