World on Track to Breach 1.5 degrees Celsius Limit by 2028 as Carbon Budget Nears Exhaustion

Rising greenhouse gas emissions are going to exhaust the world’s “carbon budget” by 2028, crossing the barrier to limit global warming to 1.5 degrees Celsius, according to a new study co-authored by a Canadian researcher, reported The Canadian Press.

The budget at current levels could get exhausted in a little more than three years, the report said. The report further found that the budgets for 1.6 and 1.7 degrees Celsius warming thresholds are at risk within the next decade.

Emphasising on the consequent climate impacts from thawing permafrost to raging wildfires, Concordia University professor Damon Matthews told The Canadian Press that “every increment matters” in the effort to avoid these incidents.

The Paris Agreement adopted in 2015 committed countries to pursue efforts to cap global warming at 1.5 degrees Celsius and keep it below two degrees compared to the pre-industrial average to avoid some of the grave climate impacts. The target was backed by small islands and emerging scientific consensus which showed it would reduce the risks of extreme heat, coastal flooding and sea level rise.

"It's a notable political failure when we breach that level, that we did not manage to get our stuff together fast enough to solve this problem," said Matthews.

"We need to have unanimous public support for really bold, ambitious system-changing action," added Matthews.

Emissions Outpace Climate Targets

According to IPCC’s 2021 estimates, the carbon budget remaining at that time was 500 tonnes of carbon dioxide emissions from 2020 onward. Till 2020-21, Down To Earth reported that about 80 billion tonnes were emitted during 2020-21, leaving 40 billion tonnes of carbon dioxide emissions in the budget after 2021.

Back then, the emissions trend suggested that this expenditure of carbon budget would be 10 years away, which is not a lot of time, however, something is always better than nothing. Fast forward to 2025, the current report suggested that carbon budget—the amount of CO2 that can be released while staying below the 1.5 degrees Celsius of global temperature—sits at about 130 billion tonnes as of the start of 2025.

Meanwhile, 2024 was already declared as the hottest year ever. Surpassing the 1.5-degree threshold in a single year does not mean the Paris target has been officially breached. However, a 2025 WMO report warned that there is a 70% chance that human-induced warming will hit or exceed 1.5 degrees Celsius within the next five years if emissions remain unchanged.