To Limit Warming to 2° C, Oil And Coal Burning Must Largely Stop, Study Says

The world must largely cease burning oil, coal, and natural gas by 2050 and can only use one-quarter of remaining carbon reserves if the goal of limiting global warming to 2° C is to be met, according to a study in the journal Nature. Researchers at Oxford University and the Potsdam Institute for Climate Impact Research forecast that there is a 50-50 chance of limiting warming to 2° C if cumulative carbon emissions are capped at 1 trillion tons. From the Industrial Revolution in the late 18th century to the present, human activity has emitted 500 billion tons of carbon into the atmosphere, the study said. Yet given current rates of combustion of coal, oil, and natural gas, it will take less than 40 years to emit the second 500 billion tons, according to Myles Allen of Oxford University. Once the threshold of 1 trillion tons is passed, warming could easily exceed 2° C, which would likely lead to severe disruption of the global climate system and rapid sea level rises, according to the Intergovernmental Panel on Climate Change. To limit emissions to 1 trillion tons, the study said that three-quarters of fossil fuels must be left in the ground as nations switch to renewable energy sources.