The Earth could exceed the critical 1.5°C global warming limit in just three years if current carbon dioxide emissions continue, say top climate scientists. More than 60 experts have shared their findings in the latest review of global warming trends, sounding an urgent call for action.
Back in 2015, nearly 200 nations agreed to try to keep the global temperature rise below 1.5°C compared to levels from the late 1800s. The aim was to prevent the most dangerous impacts of climate change. But rising emissions from burning fossil fuels and large-scale deforestation are now putting that goal at risk.
Lead researcher Professor Piers Forster, director of the Priestley Centre for Climate Futures at the University of Leeds, stated that global conditions are getting worse, not better. He noted that Earth’s temperature and sea levels are rising faster than ever. These changes, he said, directly relate to high emissions.
At the start of 2020, scientists estimated the world could emit 500 billion more tonnes of CO2 and still have a 50% chance of staying within the 1.5°C target. But by early 2025, that carbon budget will likely fall to only 130 billion tonnes. If emissions continue at the current rate of 40 billion tonnes per year, the budget would be used up in just over three years.
If the world exceeds this carbon budget, passing the 1.5°C threshold becomes more likely. While this level of warming might not happen immediately, it could happen soon after 2030. According to the researchers, this would break the climate promises made under the Paris Agreement.
Last year marked a new record. For the first time, the global average air temperature for a full year was over 1.5°C above pre-industrial levels. The 10-year average from 2015 to 2024 was 1.24°C above those levels, showing a clear trend.
While the extreme heat in 2024 was partly due to natural weather patterns, human activity was the main cause. The rate of warming is now about 0.27°C per decade. This is much faster than any period in Earth’s past, based on geological data.
Experts say that even if the 1.5°C mark is passed, it might be possible to lower the temperature again. But this would require removing huge amounts of CO2 from the atmosphere. Professor Joeri Rogelj from Imperial College London warns that it becomes harder to reverse warming the more we go over the target. He stressed that relying too much on future carbon removal technology is risky.
The study includes many alarming findings. One of the most worrying is how fast heat is building up in the climate system. This is called Earth’s energy imbalance. Over the past 10 years, the rate of heat accumulation has doubled compared to the 1970s and 1980s. It is also about 25% higher than it was during the 2000s and 2010s.
Dr. Matthew Palmer from the UK Met Office and the University of Bristol said this increase is “very worrying.” He explained that most of the extra heat comes from greenhouse gases. However, a drop in cooling aerosols in the air has also played a role.
This added heat affects the entire planet. It warms the land and air, melts ice, and raises sea levels. Oceans absorb about 90% of this extra energy. As the oceans warm, sea levels rise. This happens both because warm water takes up more space and because glaciers are melting. Since the 1990s, sea-level rise has doubled, putting millions of people in coastal areas at greater risk of flooding.
Despite the grim outlook, there is a small ray of hope. The rate of increase in emissions seems to be slowing. More clean energy technologies are being used worldwide. But scientists say that deep and fast cuts to emissions are more urgent than ever.
The 1.5°C limit is not just a symbolic line. It is backed by strong science. If the world warms by 2°C instead of 1.5°C, the risks and damage will be far worse. That’s why every small reduction in warming can help. It can reduce extreme weather, slow sea-level rise, and protect vulnerable communities.
Professor Rogelj emphasized that choices made in the next decade will shape the future. Reducing emissions now will ease the burden on people and ecosystems worldwide.
