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Hello blackouts! ‘The majority of the planet’s fossil fuel reserves must stay in the ground’ to meet ‘climate targets’

Abandoning 60% of global oil might limit warming to 1.5 C

The majority of the planet’s fossil fuel reserves must stay in the ground if the world wants even half a chance — literally — at meeting its most ambitious climate targets.

A new study published yesterday in the journal Nature found that 60 percent of oil and natural gas, and a whopping 90 percent of coal, must remain unextracted and unused between now and 2050 in order for the world to have at least a 50 percent shot at limiting warming to 1.5 degrees Celsius.

These results are broadly consistent with the findings of numerous recent reports, from the United Nations, the International Energy Agency and others, which have “all provided evidence that dramatic cuts in fossil fuel production are required immediately in order to move towards limiting global heating to 1.5 degrees,” said Dan Welsby, a researcher at University College London and lead author of the study, at a press conference announcing the results.

Under the Paris climate agreement, nations are working to keep global temperatures within 2 C of their preindustrial levels, and within 1.5 C if at all possible. Research suggests that the effects of climate change — melting ice, rising seas, more extreme weather and so on — will be worse at 2 C than at 1.5 C, and worse still at higher temperatures. These targets are an attempt to limit the consequences of global warming as much as possible.

Yet studies increasingly suggest that the 1.5 C target is looming closer and closer.

The world has already warmed by more than a degree Celsius since the start of the industrial era, which began about 150 years ago. A landmark U.N. report on climate change, released last month by the Intergovernmental Panel on Climate Change, warned that the 1.5 C mark could be reached within two decades.

To have even a 50 percent chance of meeting the target, the U.N. report suggests, the world can emit only about 460 billion metric tons of additional carbon dioxide into the atmosphere. That’s another 12 years or so of emissions at the rate at which the world is currently going.

That means global carbon emissions need to fall sharply, and immediately, in order to meet the goal.

The new study, published by four researchers from University College London, paints a similarly urgent portrait. But it looks at the future from a different angle. Instead of calculating the emissions consistent with a 1.5 C target, it calculates the amount of fossil fuel reserves that must go unused.

The study started with a carbon budget of about 580 billion metric tons of carbon dioxide. That’s based on an earlier IPCC report, from 2018, focused on the 1.5 C target. (The newest report suggests a substantially smaller budget.)

The researchers then used a special model to simulate how the world’s energy systems might evolve over the coming decades to stay within that budget. For instance, the simulations suggest a rapid shift away from fossil fuels and toward renewable energy sources. The model also assumes a substantial amount of carbon dioxide removal in the future — using various forms of technology to suck carbon out of the atmosphere.

Even with these assumptions, the strict carbon budget was “essentially the very limit of what our model can solve for,” said James Price, another author of the study. The model attempts to stick within realistic constraints on costs and the speed at which global economies can reduce their reliance on fossil fuels.

The model suggested that steep cuts in fossil fuel production are necessary between now and 2050 to meet the 1.5 C target. For certain types of fossil fuels in certain parts of the world, the model implied that production should have already peaked by now. For others, production must begin falling right away.

For all regions of the world, for instance, the study suggests that coal production should have already peaked. Oil production in all regions should have peaked by now or at least by the year 2025.

In the United States, the study suggests that 31 percent of oil reserves, 52 percent of natural gas and 97 percent of coal must stay in the ground.

These cuts are already steep. But it’s likely that the study has underestimated the challenge, the authors warn.