Global warming primarily man-made: IPCC

The Summary for Policymakers of the IPCC Working Group I assessment report approved Friday by member governments of the IPCC in Stockholm.

A fifth assessment report by the Intergovernmental Panel on Climate Change (IPCC) released Friday in Stockholm has said it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.

This indicates that scientists are able to establish with 95-100 per cent probability that human activities were increasing global warming – up from 90 per cent certainty in the IPCCs fourth assessment report of 2007 which had said it was highly likely that human activities were causing global warming.

Human influence has been detected in warming of the atmosphere and the ocean,in changes in the global water cycle,in reductions in snow and ice,in global mean sea level rise,and in changes in some climate extremes, says the report.

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The Summary for Policymakers of the IPCC Working Group I assessment report approved Friday by member governments of the IPCC in Stockholm,Sweden has observed that warming in the climate system is unequivocal and each of the last three decades has been successively warmer at the Earths surface than any preceding decade since 1850.

It has also warned that projections indicate that global surface temperature is likely to increase by 2 degree Celsius by the end of the century.

On the controversial issue of IPCC having probably overstated the increase in global warming,the summary report admits that the rate of warming over the past 15 years (1998-2012) is smaller than was calculated but points to substantial decadal variability.

In addition to robust multi-decadal warming,global mean surface temperature exhibits substantial decadal and interannual variability. Due to natural variability,trends based on short records are very sensitive to the beginning and end dates and do not in general reflect long-term climate trends.

UN report on climate change

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HUMAN RESPONSIBILITY: The panel raised the probability that human activities are the main cause of global warming since the mid-20th century to extremely likely,or at least 95 percent.

PROJECTED WARMING: The panel said the temperatures were likely to rise by between 0.3 and 4.8

degrees celsius by the late 21st century.

SEA LEVEL RISE: Sea levels are likely to rise by between 26 and 82 cm by the late 21st century.

CLIMATE SENSITIVITY: The report estimates that a doubling of carbon dioxide concentrations in the atmosphere would lead to a warming of between 1.5 and 4.5 degrees Celsius,lowering the bottom of the range from 2.0 degrees estimated in 2007 report.