Scientists caution irreversible climate damages when it comes to overshooting 1.5°C
A study coordinated by Humboldt-Universität has analysed so-called overshoot scenarios and warns of their consequences for the climate and the environment
Even if it is possible to reverse the rise of global temperatures after a temporary overshoot of 1.5°C, some climate damages triggered at peak warming will be irreversible. These are the findings of 30 scientists working in the project PROVIDE, coordinated by Humboldt-Universität zu Berlin and backed by the European innovation fund HORIZON2020. The Berlin Institute Climate Analytics as well as the Mercator Research Institute on Global Commons and Climate Change (MCC), among others, cooperated on the study published in the renowned journal Nature.
Overshoot: Irreversible damages on the climate
The scientists have studied so-called ‘overshoot’ scenarios, where temperatures temporarily exceed the Paris Agreement’s 1.5°C limit, before descending again by achieving net-negative CO2 emissions. They point out that global temperatures rising above 1,5°C will trigger damages on the climate, such as rising sea levels, which cannot be reversed. Reducing CO2-emissions as fast as possible will be decisive for minimizing the risks caused by global warming, the scientists recall.
“This paper does away with any notion that overshoot would deliver a similar climate outcome to a future in which we had done more, earlier, to ensure to limit peak warming to 1.5°C,” comments Carl-Friedrich Schleußner, honorary professor at the Institute of Geography at Humboldt-Universität HU), member of the integrated research institute IRI THESys at HU and scientific advisor at Climate Analytics, who led the study. “Only by doing much more in this critical decade to bring emissions down and peak temperatures as low as possible, can we effectively limit damages,” Schleußner says.
Carbon dioxide removal capacity needed to hedge against higher warming
The study emphasises that while there are still pathways open to limiting warming to 1.5°C or lower in the long run, there is a need to ‘hedge’ against higher warming outcomes if the climate system warms more than median estimates. To do this, ambitious emissions reductions need to go hand in hand with scaled and environmentally sustainable carbon dioxide removal technologies. A ‘preventive capacity’ of several hundred gigatonnes of net removals might be required.
“Our work reinforces the urgency of governments acting to reduce our emissions now, and not later down the line. The race to net zero needs to be seen for what it is – a sprint”, Schleußner concludes.
Further Information
- Article in Nature: “Overconfidence in climate overshoot”
- Press release published by Mercator Research Institute on Global Commons and Climate Change (MCC)
Contact
Dr. Carl-Friedrich Schleußner
Geographisches Institut der Humboldt-Universität zu Berlin
carl-friedrich.schleussner(at)hu-berlin.de
Press release HU Berlin, 6 November 2024