Global temperatures could rise 6C by end of century, say scientists  

The Guardian has a report on climate forecasts for the coming century - Global temperatures could rise 6C by end of century, say scientists.

Global temperatures are on a path to rise by an average of 6C by the end of the century as CO2 emissions increase and the Earth's natural ability to absorb the gas declines, according to a major new study.

Scientists said that CO2 emissions have risen by 29% in the past decade alone and called for urgent action by leaders at the UN climate talks in Copenhagen to agree drastic emissions cuts in order to avoid dangerous climate change.

The news will give greater urgency to the diplomatic manoeuvring before the Copenhagen summit. President Obama and President Hu of China attempted to breathe new life into the negotiations today by announcing that they intended to set targets for easing greenhouse gas emissions next month. Obama said that he and Hu would continue to press for a deal that would "rally the world".

The new study is the most comprehensive analysis to date of how economic changes and shifts in the way people have used the land in the past five decades have affected the concentration of CO2 in the atmosphere.

"The global trends we are on with CO2 emissions from fossil fuels suggest that we're heading towards 6C of global warming," said Corinne Le Quéré of the University of East Anglia who led the study with colleagues at the British Antarctic Survey.

"This is very different to the trend we need to be on to limit global climate change to 2C [the level required to avoid dangerous climate change]." That would require CO2 emissions from all sources to peak between 2015 and 2020 and that the global per capita emissions be decreased to 1 tonne of CO2 by 2050. Currently the average US citizen emits 19.9 tonnes per year and UK citizens emit 9.3 tonnes.