most of the observed warming
Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations. This is an advance since the TAR’s conclusion that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations”. Discernible human influences now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns.
international environmental agreements made to protect the environment.
The time series shows the combined global land and marine surface temperature record from 1850 to 2006. The year 2006 was sixth warmest on record, exceeded by 1998, 2005, 2003, 2002 and 2004. This time series is being compiled jointly by the Climatic Research Unit and the UK Met. Office Hadley Centre. The record is being continually up-dated and improved . This paper includes a new and more thorough assessment of errors, recognizing that these differ on annual and decadal timescales. Increased concentrations of greenhouse gases in the atmosphere due to human activities are most likely the underlying cause of warming in the 20th century.