This will happen even if we suddenly stop polluting today

Nov 25, 2013 07:49 GMT  ·  By
World may require much less carbon to tip over the brink than originally estimated
   World may require much less carbon to tip over the brink than originally estimated

A group of investigators led by scientists at Princeton University were recently able to determine that our planet's atmosphere has already received so much carbon dioxide and other greenhouse gases that it will probably continue to get warmer for centuries to come, even if we stop all CO2 emissions today. 

The most important conclusion in this research is that it may take a lot less carbon dioxide and methane than first thought to produce global warming and climate change with catastrophic effects. At this point, the threshold is believed to be somewhere around 450 parts per million (ppm) CO2 in the atmosphere.

However, the new study seems to indicate that this value may in fact be smaller, and that it may have already been reached. As such, even if we somehow managed to stop releasing greenhouse gases into the air today, the amount of CO2 in the air is sufficiently high to promote warming for centuries.

According to the latest estimates, Earth's atmosphere received no less than 1,800 billion tons of carbon from human activities. The Princeton team simulated what would happen if all CO2 inputs into the planet's atmosphere would stop suddenly.

The simulation showed that our planet's landmasses, forests and oceans would soak up 40 percent of atmospheric carbon within 20 years. By the end of the first millennium after the emission shutdown, more than 80 percent of the 1,800 billion tons of CO2 would be absorbed.

Though this sharp decrease in CO2 levels should theoretically lead to global cooling, this is not what the model has shown. As the ocean started absorbing less and less heat, global warming ensued for the next 400 years, as temperatures grew by 0.37 degrees Celsius (0.66 degrees Fahrenheit).

The UN Intergovernmental Panel on Climate Change suggests that global warming needs to be kept below 2 degrees Celsius in order to avoid the emergence of irreversible climate effects, ClickGreen reports.

“If our results are correct, the total carbon emissions required to stay below 2 degrees of warming would have to be three-quarters of previous estimates, only 750 billion tons instead of 1,000 billion tons of carbon,” explains Thomas Frölicher, a researcher at the Swiss Federal Institute of Technology, in Zurich.

“Thus, limiting the warming to 2 degrees would require keeping future cumulative carbon emissions below 250 billion tons, only half of the already emitted amount of 500 billion tons,” adds the expert, who was the first author of the new paper and a former postdoctoral researcher at Princeton.