January 17, 2025

expert reaction to Met Office data suggesting carbon dioxide emissions are off track for limiting global warming to 1.5°C

Data published by the Met Office looks at the carbon dioxide forecast for 2025.

Prof Kevin Anderson, Professor of Energy and Climate change, University of Manchester, said:

“The conclusions of this paper closely mirror those derived from an alternative scientific framework. Recent estimates of the remaining carbon budget for a 50:50 chance of limiting global warming to 1.5°C indicate that no more than 160 to 170 billion tonnes of CO2 can be emitted starting from 2025. Given that global emissions currently exceed 40 billion tonnes annually, this means emissions must be reduced by approximately 20% each year from now until they reach zero. This required 20% annual reduction aligns with the findings in Betts et al.’s research.

“What’s even more troubling is that, if all national pledges to reduce emissions are fully met, the remaining carbon budget for limiting global warming to “well below 2°C” will be as out of reach by the early 2030s as Betts et al conclude is 1.5°C today. Put simply, unless we start significantly reducing global emissions this year—and continue to do so at rates similar to the sharp decline in CO2 emissions seen during the peak of the COVID-19 pandemic— the Paris Agreement will be beyond reach by or around 2030.”

Dr Robin Lamboll, Research Fellow at the Centre for Environmental Policy, Grantham Institute – Climate Change and Environment, Imperial College London, said:

“Yet another record-breaking year of high emissions resulted in record-breaking temperatures and record-breaking CO2 concentrations – this is unsurprising. 

“Quite how much temperatures and CO2 concentrations went up by was surprising though. This was due to a mix of long-term human-caused climate change and the temporary effects, and the difficulty of working out how much was a temporary and how much systematic make it hard to use this single year to see how close we are to exceeding 1.5C in the long term. 

“The paper’s main feature, using CO2 concentrations rather than the temperature, doesn’t reduce this uncertainty as much as might be hoped, as higher temperatures tend to relate to temporary weakening of how much CO2 the earth absorbs.”

Professor Joeri Rogelj, Director of Research at the Grantham Institute – Climate Change and Environment, Imperial College London, said: 

“This forecast of the increase in atmospheric CO2 concentrations in 2025 comes as no surprise. With global CO2 emissions at record levels, concentrations of CO2 in the atmosphere will be rising accordingly.

“The headline that current CO2 trends will lead to more than 1.5°C of warming is not a new finding. UN Environment has reported repeatedly that current policies lead to emissions far above the reductions required to limit warming to 1.5°C or 2°C. The logical consequence of this is that also CO2 concentrations do not track towards these goals. 

“This highlights the importance of implementing the announced and pledged actions, and even overachieving them.

“Countries have agreed to the 1.5°C global warming limit not out of convenience but out of necessity to limit harm and suffering of people. Even if we are on track to surpass 1.5°C, these reasons don’t change, and only make a stronger case for focussed action on reducing greenhouse gas pollution.”

*‘Mauna Loa carbon dioxide forecast for 2025’ by Richard A. Betts et al. was published at 00:01 UK time on Friday 17 January 2025. 

Declared interests

Prof Kevin Anderson: No COI.

No reply to our request for DOIs was received.