This article discusses a recent climate study that warns of a vanishing safety window—here’s why. Millions of possible scenarios were analyzed, and only a few are acceptable, the scientists said. A new scientific analysis of millions of possible climate futures found only a narrow window to keeping global warming to levels the international community has deemed safe.
Out of 5.2 million possible climate futures, carbon emissions must reach zero by 2030 in every country in the world if we are to stay at less than 3.6 degrees Fahrenheit (2 degrees Celsius) by 2100 of warming, the target set by the United Nations to avoid the worst impacts of climate change, from rising seas to deadly heat waves.
And unlike last fall’s “Special Report on Global Warming of 1.5°C” from the Intergovernmental Panel on Climate Change (IPCC)—which held out the possibility of a 2.7 degree Fahrenheit (1.5 degree Celsius) climate future—the new paper published March 11 in the journal Nature Climate Change employed three practical constraints: spending to cut carbon emissions would be no more than three percent of global GDP per year; no use of geoengineering or technologies to remove carbon; and the climate’s response to doubling carbon in the atmosphere would be at the median level or higher. The latter is called climate sensitivity—how much warming happens when carbon is added to the atmosphere.