Paris overshoot modelled
Temporarily exceeding global climate targets could trigger lasting, irreversible damage, scientists warn.
A new study in Nature has raised concerns about the long-term effects of overshooting the 1.5 degrees Celsius global warming limit set by the Paris Agreement.
The research reveals that even a temporary breach could cause persistent harm, including sea level rises and ecosystem destabilisation.
The study shows that even if temperatures are eventually reduced, the impacts of peak warming could last for decades or centuries.
Sea levels could rise by an additional 40 centimetres in overshoot scenarios, further threatening coastal regions.
Scientists warn policymakers not to over-rely on carbon capture technologies to reverse warming effects.
While such methods may reduce atmospheric carbon dioxide, the large-scale deployment needed is technically and economically uncertain. Instead, the research stresses the importance of immediate emissions reductions.
“We cannot be confident that temperature decline after overshoot is achievable within the timescales expected today. Only rapid near-term emission reductions are effective in reducing climate risks,” the study says.
The study highlights that temporary overshoot could lead to long-term damage, particularly in regions vulnerable to sea-level rise, extreme weather, and ecosystem collapse.
Some impacts, once triggered, may be irreversible, making adaptation even more challenging.
Potential climate system feedback loops could amplify warming and delay temperature reversal, making the overshoot's impacts more severe.
Even if temperatures drop below 1.5 degrees in the future, sea levels may continue to rise for centuries.
This research renews calls from climate experts for immediate emissions cuts, warning that reliance on future technological fixes is too risky.
“Efforts should be concentrated on reducing emissions now, rather than banking on expensive and uncertain technologies to undo the damage later,” the authors say.