Are we underestimating the impacts of Climate Change?
A report to be published next month in the Journal of Environment Economics and Management by researchers from the University of California, suggests China’s greenhouse gas emissions have been underestimated, and probably passed those of the U.S. in 2006-2007, the BBC reports.
This isn’t the first report to find that China’s CO2 emissions have surpassed those of the United States. A report released in June by the Netherlands Environmental Assessment Agency estimated that surging power demand from China’s rapidly expanding economy caused carbon dioxide emissions to rise nine percent in 2006. That increase, coupled with a slight decline in the U.S., meant that China’s emissions for the year surpassed those of the U.S. by eight percent.
The new report warns that if China doesn’t change its energy policies, its increases in greenhouse gases will be several times larger than the cuts in emissions being made by developed nations under the Kyoto Protocol.
At the same time research from a five-year project funded by the European Union now shows that the North Atlantic, which along with the Antarctic is one of the world’s two vital ocean carbon sinks, is absorbing only half the amount of CO2 that it did in the mid-1990s.
Oceans soak up around a quarter of annual CO2 emissions, but should they fail to do so in the future the gas would stay in the atmosphere and could accelerate climate change. Oceans are like a "slow-mixing machine". Carbon absorbed in the North Atlantic takes around 1,500 years to circulate around the world’s seas. This means changes to their fragile balance could be felt long into the future.
Scientists are still debating the reasons why oceans are absorbing less carbon dioxide. While some point to CO2 saturation, others say it could be caused by a change in surface water circulation, triggered by changes in weather cycles. Project director Christoph Heinze described a "bottleneck effect" because of the large amount of man-made carbon dioxide oceans already store.
"The more CO2 the oceans store, the more difficult it will be for them to take up the additional load from the atmosphere and carbon absorption will stagnate even further," Heinze said.
Unfortunately current greenhouse gas emissions are rising worldwide much faster than expected and overall reductions in emissions are unlikely. "Emissions are growing much faster than we’d thought, the absorptive capacity of the planet is less than we’d thought, the risks of greenhouse gases are potentially bigger than more cautious estimates, and the speed of climate change seems to be faster," said Nicholas Stern, author of the Stern Report on Climate Change and former head of the World Bank, to Reuters at a conference in London this April.
The Stern report describes climate change as an economic externality and therefore addressing this externality should allow market forces to develop low carbon technologies. The report concludes that mitigation, i.e. addressing the issue now is the best economic choice.
The report predicted that, on current trends, average global temperatures will rise by 2-3 degrees centigrade in the next 50 years or so and could reduce global consumption per head by up to 20 percent, with the poorest nations feeling the most pain.
Stern now believes the risks of global warming were underestimated in his report, and that urgent action is needed to address the problem. In a recent interview with Reuters, Stern also notes that the International Panel on Climate Change report, released in 2007, made the same mistake. The report had not taken detailed account of some dangerous threats, including the failing ability of the world’s oceans to absorb CO2, because scientists had to be cautious of evidence that was just emerging.
"The IPCC has done a tremendous job but things are moving on," Stern told Reuters. "The IPCC’s (cautious) approach to this is entirely understandable and sensible, but if you’re looking ahead and asking about the risk then you do have to go beyond."
Stern said that to minimise the risks of dangerous climate change global greenhouse gas emissions should halve by mid-century. He said the United States should cut its emissions by up to 90 percent by then.
So far little action has been taken to help reduce greenhouse gas emissions from the developing world. International climate meetings such as Bali in December of 2007 and in Bangkok in March 2008 have failed to reach a consensus amongst participating nations on what measures must be undertaken next.
Increasing commitments from some countries such as the European Union to curb greenhouse gases now need to be translated into firm actions according to Stern.
As new evidence emerges, it is becoming increasingly clear that delays in action will only heighten the potential impacts of climate change.
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