Which fossil fuels must remain in the ground to limit global warming?

A third of oil reserves, half of gas reserves and over 80% of current coal reserves globally should remain in the ground and not be used before 2050 if global warming is to stay below the 2°C target agreed by policy makers, according to new research by the UCL Institute for Sustainable Resources. The study funded by the UK Energy Research Centre and published in Nature today, also identifies the geographic location of existing reserves that should remain unused and so sets out the regions that stand to lose most from achieving the 2°C goal. The authors show that the overwhelming majority of the huge coal reserves in China, Russia and the United States should remain unused along with over 260 thousand million barrels oil reserves in the Middle East, equivalent to all of the oil reserves held by Saudi Arabia. The Middle East should also leave over 60% of its gas reserves in the ground. The development of resources in the Arctic and any increase in unconventional oil - oil of a poor quality which is hard to extract - are also found to be inconsistent with efforts to limit climate change. For the study, the scientists first developed an innovative method for estimating the 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, along with low-carbon energy sources, should be used up to 2050 to meet the world's energy needs.