National climate plans can keep global warming below 2°C, study finds

Limiting global warming to 2°C above pre-industrial levels is now possible if all nations honour the climate pledges made at the Glasgow COP26 conference last year, a new study has found.

Published in the journal Nature, the peer-reviewed study outlines how updated commitments to reduce carbon emissions can keep warming “just below” the symbolic 2°C mark this century with at least a 50% likelihood.

India delivering on its new target to achieve net-zero emissions by 2070 will be key, according to the University of Melbourne's professor Malte Meinshausen, who led the study.

“When adding up the pledges of countries just a year ago, we couldn’t see 2°C being within reach,” he continued. “That has changed. Keeping the global temperature rise to just below 2°C seems possible now, if all countries honour their promises.

“Including the pledges made at COP26, we now calculate that peak warming is limited to a best estimate of around 1.9-2.0°C if all pledges, both conditional and unconditional, are sufficiently supported and honoured.”

The research team analysed the data and targets of 196 countries, plus international maritime and aviation transport emissions, and used probabilistic climate simulations to infer future warming.

Worryingly, the analysis also suggests that limiting peak warming to below 1.5°C – the higher ambition of the Paris Agreement – is unlikely if countries do not substantially upgrade their reductions targets this decade.

The Intergovernmental Panel on Climate Change Working Group III latest report concludes that limiting temperature rises to 1.5°C would require a 37% reduction in greenhouse gas emissions by 2030, compared to 2010 levels.

However, the new study estimates that, in 2030, emissions will be 6-13% higher than 2010 levels.

Co-author and climate data specialist, Jared Lewis, from climate action support organisation Climate Resource, said stronger commitments and action this decade are urgently needed to meet the 1.5°C goal.

“Meeting this goal of keeping warming around 1.5°C will allow us to mitigate some of the worst outcomes from climate change, including extreme heatwaves, coral reef bleaching, increasing flood and prolonged rain events,” he added.