Record greenhouse gas emissions could exhaust Earth’s “carbon budget” in as little as three years, dooming the planet to breach the symbolic threshold of 1.5 degrees Celsius (2.6 degrees Fahrenheit) warming.

Global warming of 2 C (3.6 F) is considered an important threshold — warming beyond this greatly increases the likelihood of devastating and irreversible climate breakdown that include extreme heatwaves, droughts and the melting of the Greenland and West Antarctic ice sheets. Under the 2015 Paris Agreement, nearly 200 countries pledged to limit global temperature rises to ideally 1.5 C and safely below 2 C. Yet, according to a new assessment by more than 60 of the world’s leading climate scientists, this target is quickly moving out of reach — only 143 billion tons (130 billion metric tons) of carbon dioxide remains before we have likely exceeded the Paris Agreement target, and humanity is already releasing over 46 billion tons (42 billion metric tons) each year. The researchers published their findings June 19 in the journal Earth System Science Data.

“The window to stay within 1.5 C is rapidly closing,” study co-author Joeri Rogelj, a professor of climate science and policy at Imperial College London, said in a statement. “Global warming is already affecting the lives of billions of people around the world. Every small increase in warming matters, leading to more frequent, more intense weather extremes.” Warnings that the Earth is careening beyond the 1.5 C limit, and the dire consequences that would follow from such a breach, are not new. In 2020, the United Nation’s Intergovernmental Panel on Climate Change (IPCC) estimated Earth’s remaining climate budget to be around 550 billion tons (500 billion metric tons). Yet with emissions reaching record highs in the years since, and the next IPCC report not due until 2029, the scientists behind the new annual study wanted to fill the gap.

The paper made its assessment by looking at 10 indicators of climate change, including net greenhouse gas emissions, Earth’s energy imbalance, surface temperature changes, sea-level rises, global temperature extremes, and the remaining budget. The scientists’ analysis makes for alarming reading, with warming occurring at a rate of about 0.49 F (0.27 C) each decade and the world standing at about 2.2 F (1.24 C) above preindustrial averages.