Actu-environment, 02 / 05 / 05 by CS
A team of researchers led by James Hansen, director of space studies at the Goddard Institute at NASA, the US space agency has calculated that the Earth is retaining 0,85 watts (+/- 0,15) of more energy per square meter it emitted over a given period when this figure was only a few tenths of a Watt before 1960. These results were published Thursday in Science Express.
According to James Hansen, author of the article, this energy imbalance is the clue that scientific estimates of the impact of human activity on the climate are correct.
These calculations could be accomplished using computer models of oceanography and climatological stations installed on buoys in the oceans or in land stations whose data are collected by satellites. According to his data, the level of the oceans has already increased by 3,2 centimeters since 1993 and even if this variation seems small, it is in fact twice as important as that recorded over the whole of the last century.
In addition, the oceans retain heat longer than the ground and play the role of thermal accumulators with a phenomenon which occurs in the ocean depths, and called "thermal inertia".
This means that if we completely stopped anthropogenic greenhouse gas emissions we can expect a rise of 0,6 degrees Celsius.
In other words the author clearly indicates in his introduction that the reduction of GHG emissions must be undertaken promptly and that if the world decides to have more evidence of atmospheric warming before acting, the phenomenon of thermal inertia of the oceans foreshadows even greater climate change that will be excessively difficult if not impossible to avoid.