To limit warming, most fossil fuel must remain untapped: study

The majority of the planet’s oil, gas and coal must remain in the ground to provide just a 50 percent chance of limiting the amount the Earth has warmed to 1.5 degrees Celsius, according to a new study. 

The study, published in the journal Nature, found that 58 percent of the planet’s oil, 59 percent of its gas, and 89 percent of its coal as of 2018 needed to remain unextracted in the year 2050 to provide a chance of limiting warming to 1.5 degrees Celsius. 

It said that this means that many parts of the world will need to reach peak fossil fuel production soon and shouldn’t start new fossil fuel projects. 

“This implies that most regions must reach peak production now or during the next decade, rendering many operational and planned fossil fuel projects unviable,” the study said. 

It also said that its findings likely underestimate the changes needed because more planet-warming fuel would need to remain untapped to get more than a 50 percent chance of limiting warming to 1.5 degrees and because of uncertainties about how soon emission-reducing technologies will be deployed. 

The scenario pitched in the study would have U.S. oil production grow until 2025 and then decline after that. 

It said that for the U.S., gas should have peaked last year and should decline by about 8.1 percent per year to avoid more dramatic warming. 

The scientists used an energy systems model to assess the levels of fossil fuels to make their calculations.

The study follows a recent United Nations report that predicted that the world will reach 1.5 degrees of warming compared to preindustrial levels sometime this century but could bounce back to less than that by the end of the century if the world reaches net-zero greenhouse gas emissions by the middle of the century. 

The U.N. has also found that keeping warming below this level would prevent certain climate-related effects on extreme weather, biodiversity and food security. 

The most recent U.N. report found that the planet has already achieved nearly 1.1 degrees of warming.