Average temperatures across the world are on course to rise by up to 6C without urgent action to curb CO2 emissions, according a new analysis.

一项新调查显示，如果不对二氧化碳的排放进行紧急控制的话，全球平均气温将上升6华氏温度。

Emissions rose by 29% between 2000 and 2008, says the Global Carbon Project.

All of that growth came in developing countries, but a quarter of it came through production of goods for consumption in industrialised nations.

The study comes against a backdrop（背景） of mixed messages on the chances of a new deal at next month's UN climate summit.

According to lead scientist Corinne Le Quere, the new findings should add urgency to the political discussions.

"Based on our knowledge of recent trends and the time it takes to change energy infrastructure, I think that the Copenhagen conference next month is our last chance to stabilise at 2C in a smooth and organised way," she told BBC News.

"If the agreement is too weak or if the commitments are not respected, it's not two and a half or three degrees that we will get, it's five or six - that's the path that we are on right now."

Professor Le Quere, who holds posts at the UK's University of East Anglia and the British Antarctic Survey, is lead author on the study that is published in the journal Nature Geoscience.

Rising sinks

The Global Carbon Project (GCP) is a network of scientists in academic institutions around the world.

It uses just about every source of data available, from atmospheric observations to business inventories（商业库存）, to build up a detailed picture of carbon dioxide emissions, carbon sinks, and trends.

Before about 2002, global emissions grew by about 1% per year.

Then the rate increased to about 3% per year, the change coming mainly from a ramping up in China's economic output, before falling slightly in 2008 as the global economy dipped towards recession.

Endorsing similar projections from the International Energy Agency, the GCP suggests emissions will fall by about 3% during 2009 before resuming their rise as the recession ends.

Concentrations in the atmosphere also show an upward trend - as monitored at stations such as Mauna Loa in Hawaii - but at a lower rate.

The team believes that carbon sinks - the oceans and plants - are probably absorbing a slightly lower proportion of the carbon dioxide from fossil fuel emissions than they were 50 years ago, although researchers admit that uncertainty about the behaviour of sinks remains high.

Industrial emissions have climbed, but those from land use change have remains constant.

As a consequence, the proportion of global emissions coming from deforestation（采伐森林） has fallen - about 12% now compared with 20% in the 1990s.

"One implication of this low fraction（分数，小部分） is that there is only limited scope for rich nations to offset（弥补，抵消） emissions by supporting avoidance of deforestation in tropical countries like Indonesia and Brazil," observed Michael Rapauch from the Australian government research agency CSIRO and co-chair of the GCP.

A mechanism for Reducing Emissions from Deforestation and forest Degradation (REDD) is due to be concluded at next month's summit.