viernes, 16 de diciembre de 2011
The effect of GHG emissions and deforestation yet made by man may be more dangerous than what scientists have ever forecasted. Talks in Durban to limit global temperature rises to 2C, agreed in Copenhagen Conference in 2009, will not prevent the possibility of dangerous climate change, warns Dr. Hansen, the scientist who first raised the alarm over global warming at US senate hearings in 1988. He believes carbon dioxide concentrations – now at nearly 389 parts per million (ppm) – should be no higher than 350ppm to stop catastrophic events such as the melting of ice sheets, dramatic sea level rises and methane being released from beneath the permafrost.
Signs of these possible effects of climate change have been observed. In an exclusive interview with The Independent, Igor Semiletov, of the Far Eastern branch of the Russian Academy of Sciences, said that he has never before witnessed the scale and force of the methane– a greenhouse gas 20 times more potent than carbon dioxide – being released from beneath the Arctic seabed.
"Earlier we found torch-like structures like this but they were only tens of metres in diameter. This is the first time that we've found continuous, powerful and impressive seeping structures, more than 1,000 metres in diameter. It's amazing," Dr Semiletov said. "I was most impressed by the sheer scale and high density of the plumes. Over a relatively small area we found more than 100, but over a wider area there should be thousands of them."
Scientists estimate that there are hundreds of millions of tonnes of methane gas locked away beneath the Arctic permafrost, which extends from the mainland into the seabed of the relatively shallow sea of the East Siberian Arctic Shelf. One of the greatest fears is that with the disappearance of the Arctic sea-ice in summer, and rapidly rising temperatures across the entire region, which are already melting the Siberian permafrost, the trapped methane could be suddenly released into the atmosphere leading to rapid and severe climate change.
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The solution can come through curbing GHG emissions turning to renewable sources of energy , further actions in efficient use of energy and too by stopping deforestation and instead promoting afforestation. Today great emitters of some developing countries, China and India, think that reducing or limiting their GHG emissions imply a reduction in their necessary development to satisfy people demands. Other great emitters of developed countries, USA, perhaps doesn’t limit their emissions waiting for a solution in the advancement of science and technology to make the alternatives of green economies more attractive and competitive than the actual traditional economy responsible of GHG emissions made by man. It is time to act beginning in planning a road map so as to limit GHG emissions and to invest much more in R+ D+ I in green economies.