Emissions Report

The UN's annual Emissions Gap Report found that the world will likely surpass the 1.5°C warming threshold within the next decade.

Context

The 2015 Paris Agreement committed countries to reduce greenhouse gas emissions and limit global temperature rise to 2°C above pre-industrial levels, with an aspirational goal of staying below 1.5°C. These targets were based on scientific assessments showing that each increment of warming causes progressively worse impacts: 2°C of warming would more than double the population exposed to extreme heat compared to 1.5°C, while 1.5°C would destroy at least 70% of coral reefs versus 99% at 2°C.

Pledges Insufficient

On Tuesday, the United Nations Environment Programme’s report projected that under current government policies already in place, global temperatures would rise by approximately 2.8°C this century. If countries meet their latest emissions-cutting pledges, warming would reach 2.3 to 2.5°C, falling short of the Paris Agreement’s targets. 

This represented only a 0.3°C improvement from last year's projections, largely due to updated greenhouse gas calculation methods rather than substantially stronger climate commitments from countries. The report's lead author stated that while deeper emissions cuts now could delay when the overshoot occurs, "we can no longer totally avoid it."

Emissions Cuts Needed

The report found that by 2035, countries must cut annual greenhouse gas emissions by 35% compared to 2019 levels to align with a 2°C pathway, or by 55% for a 1.5°C pathway. Global greenhouse gas emissions instead increased by 2.3% in 2024.

According to the UN, the world can only emit another 80B to 130B tonnes of carbon dioxide before crossing the 1.5°C threshold, which at current emission rates of roughly 40B tonnes per year, would be reached by the end of the decade.

Carbon Removal

Once the world exceeds a 1.5°C increase, bringing temperatures back down will require removing far more carbon dioxide from the atmosphere, for example by storing it in forests or underground reservoirs. According to a 2021 study by researchers of Imperial College London published in Nature, reversing each 0.1°C of warming would require removing 220B tonnes of carbon dioxide – roughly five years' worth of current global emissions. Beyond Earth’s natural ability to absorb greenhouse gases – such as through forests and oceans, current engineered carbon dioxide removal methods absorb only about 2B tonnes annually.