Global Carbon Budget on Track for Depletion by 2028, New Study Warns

A recent study published in Earth System Science Data on June 18, 2025, warns that the planet's remaining "carbon budget"—the maximum amount of CO₂ emissions compatible with limiting global warming to 1.5°C—is on track to be exhausted within three years. The study, conducted by over 60 international scientists, indicates that the carbon budget has decreased from 500 billion tonnes in 2021 to just 130 billion tonnes in 2025, primarily due to record-high greenhouse gas emissions in 2024. This rapid depletion makes it increasingly unlikely to meet the Paris Agreement's goal of keeping global temperature rise below 1.5°C. The research highlights that climate action is not progressing rapidly enough to match escalating emissions, with observed warming over the past decade averaging 1.24°C above pre-industrial levels. The findings come as global leaders meet for climate talks in Germany, amid criticisms of insufficient political action.

The study reports a significant reduction in the remaining carbon budget, from 500 billion tonnes in 2021 to 130 billion tonnes in 2025. This decline is attributed to record-high greenhouse gas emissions in 2024. The average global temperature over the decade leading up to 2024 was 1.24°C above pre-industrial levels, with human-caused warming accounting for 1.22°C. This warming is primarily driven by deforestation and the burning of fossil fuels. The rate of global heating between 2012 and 2024 has doubled compared to the 1970s and 1980s, leading to sea-level rise, ocean warming, ice loss, and permafrost thawing.

The acceleration of global warming is expected to result in more frequent and severe extreme weather events, including heatwaves, droughts, storms, and sea-level rise. These changes pose significant risks to human health, agriculture, water resources, and infrastructure. Rising sea levels and increased storm surges threaten coastal communities, leading to potential displacement, loss of livelihoods, and economic instability. The failure to limit global warming to 1.5°C could result in substantial economic losses due to damage to infrastructure, decreased agricultural yields, and increased healthcare costs associated with climate-related illnesses.

The Paris Agreement, adopted in 2015, is an international treaty aimed at limiting global warming to well below 2°C, preferably to 1.5°C, compared to pre-industrial levels. Achieving this goal requires significant reductions in greenhouse gas emissions and a transition to renewable energy sources.

The study's release coincides with global climate talks in Bonn, Germany, where leaders are discussing strategies to combat climate change. The United States, under President Donald Trump, has withdrawn from the Paris Agreement, raising concerns about the effectiveness of international efforts.

Previous studies have warned about the rapid depletion of the carbon budget and the challenges in meeting the 1.5°C target. However, the current study highlights an unprecedented acceleration in emissions and warming rates, making the goal increasingly unattainable.

The recent study underscores the critical need for accelerated and comprehensive climate action to prevent surpassing the 1.5°C warming threshold. The findings serve as a stark reminder of the limited time remaining to implement effective mitigation strategies and the profound implications of inaction.