Record Global Emissions Put Warming on Track for ‘Catastrophic’ 2.6-3.1°C, UN Warns

Governments’ current climate policies and promises have the world on track for “catastrophic” average global warming of 2.6° to 3.1°C, and the odds of limiting global heating to the 1.5°C target in the Paris climate agreement are rapidly shrinking toward zero, the United Nations Environment Programme (UNEP) warns in the latest edition of its annual Emissions Gap Report.

“Every fraction of a degree avoided counts in terms of lives saved, economies protected, damages avoided, biodiversity conserved, and the ability to rapidly bring down any temperature overshoot,” UNEP writes in a key messaging document that accompanied the release Thursday morning.

But while “it remains technically possible to cut emissions in line with a 1.5°C pathway,” the document adds, delivering on that potential “would require immediate global mobilization on a scale and pace only ever seen following a global conflict.”

UNEP says global greenhouse gas emissions hit another new record last year at 57.1 billion tonnes of carbon dioxide equivalent (CO2e), a 1.3% increase from 2022. On a global scale, the power sector was the biggest climate polluter, at 15.1 gigatonnes, followed by transport at 8.4 Gt, and agriculture and industry at 6.5 Gt each. G20 countries accounted for 77% of global emissions, compared to 5% from Africa and 3% from the world’s 47 least developed countries.

The United States had the highest per capita emissions, at 18 tonnes per person, and the highest historical emissions between 1850 and 2022, at 527 Gt. China placed second on both metrics, at 11 tonnes per person in 2023 and 300 Gt historically, a virtual tie with the European Union at 301 Gt.

The report traces much of the emissions gap to countries that adopted “globally insufficient” emission reduction pledges for 2030, then failed even to meet those targets. Seven of the G20 countries—China, India, Indonesia, Mexico, Saudi Arabia, South Korea, and Türkiye—have not yet peaked their emissions, an initial threshold seen as a “prerequisite to reaching net-zero”.

These and other failures add up to a large emissions gap compared to the trajectories that would be needed to hold average global warming to 1.5° or even 2°C, UNEP states. “Unless global emissions in 2030 are brought below levels resulting from current policies and from the full implementation of the current NDCs [Nationally Determined Contributions, countries’ voluntary commitments under the Paris deal], it will become impossible to get to a pathway that limits global warming to 1.5°C with no or limited overshoot,” and “strongly increase the challenge of limiting warming to 2°C.”

UNEP says countries have lost ground on their emission reduction pledges over the last four years. The least expensive pathways to limiting average warming to 1.5°, 1.8°, or 2°C all assume decisive action beginning in 2020, in time to drive “deep GHG reductions this decade,” UNEP writes. But after the sudden drop brought on by the COVID-19 pandemic, countries’ carbon dioxide and methane emissions began rising again.

“The lack of action and time lost has implications,” beginning with 20 to 35 gigatonnes of additional emissions this decade, the report states. “Importantly, inaction reduces the chance of bridging the emissions gap in 2030 because of continued lock-in of carbon-intensive infrastructure and less time available to realize the emission reductions required. It further adds risks of temperature overshoot and compounds increasingly severe climate impacts, some of which are irreversible.”

The report puts the onus on the world’s 20 wealthiest countries to reduce their emissions faster than the global average, with UNEP’s messaging document expressing the unlikely hope that this year’s COP29 climate summit in petrostate Azerbaijan will serve as a “launchpad to increase ambition and ensure the new NDCs collectively promise to almost halve greenhouse gas emissions” by the end of this decade.

“It remains technically possible to get on a 1.5°C pathway, with solar, wind, and forests holding real promise for sweeping and fast emissions cuts,” the document states. But “to deliver on this potential, sufficiently strong NDCs would need to be backed urgently by a whole-of-government approach, measures that maximize socioeconomic and environmental co-benefits, enhanced international collaboration that includes reform of the global financial architecture, strong private sector action, and a minimum six-fold increase in mitigation investment,” with the “heavy lifting” coming from G20 nations.

Cover photo: Denis Onyodi / IFRC/DRK via Climate Visuals