Nov. 25 (UPI) -- Even if humans were able to stop all carbon emissions absorbed by our atmosphere, researchers said that it would not stop global warming.
The Princeton University-led research suggests that temperatures would still continue to rise as a result of the residual CO2 in the atmosphere, and that the amount of CO2 required to raise the temperature of Earth may be much lower than previously calculated.
"Scientists have thought that the temperature stays constant or declines once emissions stop, but now we show that the possibility of a temperature increase can not be excluded," said Thomas Frolicher, the climate study's lead author. "This is illustrative of how difficult it may be to reverse climate change -- we stop the emissions, but still get an increase in the global mean temperature."
The immediate effect of a hypothetical shutdown of emissions would be a cooling. But after a 100 years the warming would start again and in the next 400 years the model predicts global temperatures to rise 0.66 degrees Fahrenheit. For comparison, the global temperature rise since the industrial era has been 1.5 °F.
According to the IPCC, a U.N. body and an internationally accepted voice on climate change, a rise of 2 degrees Celsius from pre-industrial levels, or 3.6 °F, could have a devastating effect on the climate. The body has tried to limit our CO2 emissions to 1,000 billion tons, half of which has already been put into the atmosphere.
But Frolicher's study, published in the journal Nature Climate Change, suggests that the 2 °C rise may be achieved with a lot less CO2 in the atmosphere.
"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," Frolicher said.
The reason for this disparity in figures is that previous models did not take into account the gradual reduction in the ocean's ability to absorb heat from the atmosphere, particularly at the poles.
[Princeton University] [Nature World News]