LONDON – Two-thirds of the world’s fossil-fuel reserves must remain unburnt to hold temperature increases below dangerous levels, according to researchers at University College London.
Half the world’s known gas reserves, one-third of the oil and 80 percent of the coal should remain in the ground and unused before 2050 to limit temperature increases to 2 degrees Celsius, the maximum climate scientists say is advisable, according to a report from the UCL Institute for Sustainable Resources.
“Policy makers must realize that their instincts to completely use the fossil fuels within their countries are wholly incompatible with their commitments to the 2 degrees Celsius goal,” UCL research associate and lead author Christophe McGlade said in the report, which was published recently in the scientific journal Nature.
The research will heighten the debate about so-called stranded assets, the idea that the reserves of oil drillers and coal miners have little value because the fight against climate change will require them to be left in the ground.
While disputed by energy companies, the issue has been gaining greater prominence in recent months. Bank of England Gov. Mark Carney said last year he’d instructed staff to consider whether stranded assets posed a threat to banks, investors and the financial system.
The UCL report, funded by the U.K. Energy Research Center, said that the “overwhelming majority” of coal reserves in China, Russia and the U.S. must remain unburnt, along with 260 billion barrels of Middle East oil and 60 percent of its gas reserves.
Governments are adopting policies to cut carbon dioxide emissions and meet the 2 degrees Celsius target agreed in Copenhagen six years ago.
The International Energy Agency estimates that based on current trends the world may warm 3.6 degrees Celsius by the end of the century, raising the risk of more violent storms, droughts and rising sea levels.
The United Nations said in November that the world must halt fossil-fuel emissions within the next six decades to prevent irreversible impacts from a warming planet.
The U.N. estimates that to stand a 50 percent chance of holding global warming to 2 degrees Celsius, emissions since the late 19th century need to be limited to 3,000 gigatons of carbon dioxide, with 63 percent of that already released by 2011. That means there’s 1,100 gigatons left, or at best 30 percent of the 3,700 gigatons to 7,100 gigatons of carbon dioxide contained in known fossil fuel reserves that are economically recoverable, according to the U.N.
The world’s biggest producers of coal, oil and gas reject the concept of stranded assets, saying fossil fuels are needed to provide affordable energy.
Exxon Mobil Corp. said in March that its natural-gas reserves won’t become stranded as global demand grows and the drive for higher living standards in developing nations trumps efforts to curtail carbon emissions.
Glencore, the biggest coal exporter, said in its sustainability report that fossil fuels will be a vital element of the world’s energy sources for some time to come.