External control of 20th century temperature by natural and anthropogenic forcings

A comparison of observations with simulations of a coupled ocean-atmosphere general circulation model shows that both natural and anthropogenic factor s have contributed significantly to 20th century temperature changes. The m odel successfully simulates global mean and Large-scale Land temperature va riations, indicating that the climate response on these scales is strongly influenced by external factors. More than 80% of observed multidecadal-scal e global mean temperature variations and more than 60% of 10- to 50-year La nd temperature variations are due to changes in external forcings, Anthropo genic global warming under a standard emissions scenario is predicted to co ntinue at a rate similar to that observed in recent decades.