Earth is on track to exceed the 1.5°C global warming threshold in just over three years if current carbon emissions continue unchecked, according to a major international climate update.
The study, published by the Indicators of Global Climate Change (IGCC) consortium, estimates the remaining carbon budget for 1.5°C warming is around 130 billion tonnes of carbon dioxide — from the beginning of 2025. That budget could be gone in little more than three years.
“The window to stay within 1.5°C is rapidly closing. Every small increase in warming matters, leading to more frequent, more intense weather extremes.”
– Centre for Climate Futures Professor Joeri Rogelj.
“Continued record-high emissions of greenhouse gases mean more of us are experiencing unsafe levels of climate impacts,” says lead author Professor Piers Forster, Director of the Priestley Centre for Climate Futures at the University of Leeds.
“Temperatures have risen year-on-year since the last IPCC [Intergovernmental Panel on Climate Change] report in 2021, highlighting how climate policies and pace of climate action are not keeping up with what’s needed to address the ever-growing impacts.”
The 1.5°C target has long been a cornerstone of international climate efforts. Under the Paris Agreement, adopted in 2015 by nearly 200 nations, countries pledged to keep warming “well below 2°C” and to “pursue efforts” to limit it to 1.5°C above pre-industrial levels.
According to the study, 2024 saw the highest global surface temperatures on record — an average increase of 1.52°C, with 1.36°C of that attributed directly to human activities. Although a single year above 1.5°C doesn’t constitute a formal breach of the Paris threshold — which requires sustained exceedance over decades — the trajectory is unmistakable.
Human-driven emissions have averaged 53 billion tonnes of CO₂ equivalent per year over the past decade, largely from burning fossil fuels and deforestation. And in 2024, emissions from international aviation — the sector that saw the sharpest drop during COVID-19 lockdowns — rebounded to pre-pandemic levels.
“The window to stay within 1.5°C is rapidly closing. Global warming is already affecting the lives of billions of people around the world,” warns Professor Joeri Rogelj, the Research Director at the Grantham Institute. “Every small increase in warming matters, leading to more frequent, more intense weather extremes”.
The report also estimates that warming could surpass 1.6°C or 1.7°C within the next decade if emissions stay on their current path.
Scientists say the next few years are critical.
“Emissions over the next decade will determine how soon and how fast 1.5°C of warming is reached,” says Rogelj. “They need to be swiftly reduced to meet the climate goals of the Paris Agreement.”