FORGET fire, it's the smoke that matters. In the lead-up to the climate change summit in Doha, Qatar - which wraps up at the end of this week - study after study painted a grim picture of our future, from sea level rising faster. The worst news, however, is that far from cutting our emissions, we are pumping more greenhouse gases into the atmosphere than ever.
The latest figures from the Global Carbon Project, released this week, show that global emissions have been growing at an average of 3 per cent each year since 2000. We are on course to emit 35.6 billion tonnes of carbon dioxide this year just from burning fossil fuels and producing cement - a 58 per cent increase on 1990 levels, and this doesn't include another 3 billion tonnes or so of emissions from deforestation and other changes in land use (Nature Climate Change, doi.org/jwf).
China, now the biggest emitter, is responsible for most of this growth. "It's a slow tsunami," says the head of the project, Pep Canadell of Australia's national science institute CSIRO in Canberra. China's emissions are expected to grow until at least 2030. Even if they do peak by then, the emissions of other developing nations, particularly India with its 1.2 billion people, may continue to climb. The World Resources Institute reported last month that there are plans to build 1200 new coal-fired stations globally, most in India and China.
So there is little prospect of global emissions peaking around 2020 - which is what is needed to stop the world warming more than 2??C. Limiting warming to 2??C is still possible, but after decades of inaction, it would now take an unprecedented global effort to achieve it. "If this is not forthcoming, 2??C is beyond our grasp and even 4??C begins to look challenging," says Kevin Anderson of the Tyndall Centre for Climate Change Research in Norwich, UK. Each year you don't do anything, the challenge grows greater, he adds.
Some countries have pledged to cut their emissions, but even if all existing pledges were kept - which seems unlikely - there is still a one in five chance that the world could warm by over 4??C, a report commissioned by the World Bank warned last month. If we carry on as we are, temperatures could rise more than 4??C well before 2100, and more than 8??C before 2150.
This is not even the worse-case scenario. Some studies suggest that the rise in temperature will be 4??C by the 2070s. The simulations on which these projections are based do not include the possibility of vast amounts of carbon being released from melting permafrost and undersea hydrates. Last week, reports from NASA and the UN warned that permafrost is already melting fast and that there could be extensive losses by 2100.
At the moment, however, we are pumping such amounts of carbon into the atmosphere that even massive releases of carbon from natural sources will not make much of a difference. Estimates suggest they will only lead to a small amount of extra warming. Instead, the real threat is more subtle - it's that the longer we delay cuts, the less difference they will make, because by the time our emissions start to fall, the land and oceans won't be able to take in any more carbon and will begin releasing it.
Meanwhile, the consequences of the 0.8??C warming that has already happened since pre-industrial times are becoming ever more apparent. Studies out last week confirmed that ice in Greenland and Antarctica is melting much faster than predicted, for instance. Global sea level has already risen about 20 centimetres, largely because of the expansion of water as it warms, and this has undoubtedly increased the damage caused by storm surges such as that of superstorm Sandy.
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