The window to limit global warming to 1.5°C is closing
Illustration: Annelise Capossela/Axios
Just 20 out of 400 of the climate scenarios examined in a landmark 2018 United Nations climate report would have a realistic chance of limiting global warming to 1.5°C (2.7°F) above preindustrial levels by 2100, a new study finds.
Why it matters: The study, by more than a dozen researchers from around the world, shows that even the scenarios they identified would still need to employ at least one carbon emissions reduction technology at a level they classify as challenging.
The big picture: Many of the scenarios used for the U.N. study relied heavily on employing technologies that pull carbon out of the air and store it permanently in the ground.
Of the over 400 climate scenarios assessed in the 1.5°C report by the Intergovernmental Panel on Climate Change (IPCC), only around 50 scenarios avoid significantly overshooting 1.5°C. Of those only around 20 make realistic assumptions on mitigation options, for instance the rate and scale of carbon removal from the atmosphere or extent of tree planting, a new study shows. All 20 scenarios need to pull at least one mitigation lever at challenging rather than reasonable levels.
Of the over 400 climate scenarios assessed in the 1.5°C report by the Intergovernmental Panel on Climate Change (IPCC), only around 50 scenarios avoid significantly overshooting 1.5°C. Of those only around 20 make realistic assumptions on mitigation options, for instance the rate and scale of carbon removal from the atmosphere or extent of tree planting, a new study shows. All 20 scenarios need to pull at least one mitigation lever at challenging rather than reasonable levels.