USA Today, 31 July 2017
A scientific study released Monday said that the Earth’s atmosphere will warm by at least another 2 degrees C (3.8 degrees F) — regardless of what we do in the future to limit greenhouse gas emissions.
There’s only a 5% chance that Earth will warm 2 degrees or less by the end of this century, the study said. It shows a mere 1% chance that warming could be at or below 1.5 degrees, which was the target set by the landmark 2016 Paris Agreement.
“Our analysis is compatible with previous estimates, but it finds that the most optimistic projections are unlikely to happen,” said study lead author Adrian Raftery of the University of Washington. “We’re closer to the margin than we think.”
The burning of fossil fuels such as gas, oil and coal is causing the planet to warm to levels that cannot be explained by natural factors, scientists say.
To come up with his conclusion, Raftery and his team looked at total world population, gross domestic product per person and the amount of carbon emitted for each dollar of economic activity.
The Paris Agreement of 2016 was signed by 195 countries including the United States to keep global temperature rise less than 2 degrees above pre-industrial levels. President Trump pulled the U.S. out of the pact earlier this year.
“Overall, the goals expressed in the Paris Agreement are ambitious but realistic,” Raftery said. “The bad news is they are unlikely to be enough to achieve the target of keeping warming at or below 1.5 degrees C.”
The second study was also published in Nature Climate Change and was led by Thorsten Mauritsen of the Max Planck Institute for Meteorology in Germany and Robert Pincus of the University of Colorado.
“Our estimates are based on things that have already happened, things we can observe, and they point to the part of future warming that is already committed to by past emissions,” Mauritsen said. “Future carbon dioxide emissions will then add extra warming on top of that commitment.”