LONDON – A third of the world’s oil reserves, half of gas reserves and 80 percent of current coal reserves should not be used in the coming decades if global warming is to stay below an agreed 2 degrees Celsius target, scientists said Wednesday.
In a study published in the journal Nature, researchers said the vast majority of coal reserves in China, Russia and the United States should stay in the ground, as well as more than 260,000 million barrels of oil reserves in the Middle East, equivalent to all of Saudi Arabia’s oil reserves.
The Middle East should also leave more than 60 percent of its gas reserves in the ground, the study found.
“Policymakers must realize that their instincts to completely use the fossil fuels within their countries are wholly incompatible with their commitments to the 2 degrees C goal,” said Christophe McGlade, who led the study at University College London’s Institute for Sustainable Resources.
He said policymakers and the public should be made aware of the discrepancy between what they are doing and what they are saying — particularly ahead of United Nations talks on a deal to combat global warming due in Paris in December.
For the study, McGlade and his research assistant, professor Paul Ekins, director of the UCL Institute, first used various published studies to estimate quantities, locations and nature of the world’s oil, gas and coal reserves and resources.
They then used an integrated assessment model to explore which of these, as well as low-carbon energy sources such as nuclear and renewable energy sources, should be used up until 2050 to meet the world’s energy needs.
Ekins, a UCL professor of resources and environmental policy, said investors in energy companies should take note of the study’s findings, and question whether they might want to hedge their bets.
“Greater global attention to climate policy . . . means that fossil fuel companies are becoming increasingly risky for investors in terms of the delivery of long-term returns,” he said. “I would expect prudent investors in energy to shift increasingly toward low-carbon energy sources.”
He said energy companies spent more than $670 billion last year searching for and developing new fossil fuel resources, which may never be extracted or used if politicians stick to their word on limiting global warming.
The scientists compared their findings with a wide variety of alternative modeling approaches from groups across the world, and said their results were consistent.
Almost 200 countries have set a 2 C global average temperature rise above preindustrial times as a ceiling to limit climate change, which scientists say will bring more droughts, floods, heat waves and rising sea levels.