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Delegates arriving at the UN COP31 climate conference in Antalya for 12 days of talks.Credit: Sandro Basili/Shutterstock
The United Nations annual climate meeting starting today is the first to take place after confirmation that global warming will overshoot the headline limit of 1.5 °C. The aim of keeping warming within 1.5 °C above pre-industrial temperatures was set out in the 2015 Paris agreement.
As tens of thousands of delegates and observers arrive in Antalya, Turkey, for the COP31 meeting, some scientists and climate advocates say the 12-day event must discuss how to deal with the overshoot. Along with cutting emissions, this includes practical ways of removing massive volumes of carbon dioxide from the atmosphere.
The UN Environment Programme last month acknowledged that, under all plausible emissions trajectories, the world will surpass the 1.5 °C target agreed at COP21 in Paris. Its Limiting Overshoot report is the first UN report to state explicitly that overshoot is now inevitable. It also laid out how to bring temperatures back below the 1.5 °C target this century.
In addition to slashing emissions to near-zero levels, the report confirmed the need to remove hundreds of billions of tonnes of CO2 from the atmosphere this century, either using CO2 removal technologies or nature-based approaches such as reforestation. “[K]eeping 1.5 °C within reach requires climate policy to evolve to include the removal of already emitted [greenhouse gases],” the report states.
This idea to limit the “magnitude and the duration” of overshooting 1.5 °C is expected to shape discussion among parties at the COP meeting, says Clea Schumer, a research associate at the World Resources Institute, an environmental research and advocacy organization in Washington DC. Some language on limiting overshoot was included in the final decision of the COP30 summit last year in Belém, Brazil, but CO2 removal has mostly gone unmentioned.
Most governments “are happy that they finally don’t have to pretend any more that we will make it” to 1.5 °C, says Oliver Geden, a researcher at the German Institute for International and Security Affairs in Berlin. They now want to limit overshoot, “but how we actually do that, nobody is talking about”, he adds.
Steve Smith, a climate researcher at the University of Oxford, UK, agrees. CO2 removal has sparked controversy in the past over concerns that it might distract from the need to cut emissions. But it is possible that CO2 removal could move up the agenda amid discussions about the necessary return from overshoot, he says.
Environmental advocacy groups, such as New York-based Natural Resources Defense Council (NRDC), that had been skeptical of CO2 removal, have now changed their position. A report from the organisation in September called on environmentalists to support CO2 removal in the same way they supported renewable energy and electrification.