The concentration of carbon dioxide in Earth’s atmosphere has reached its highest level in 800,000 years, according to a United Nations (UN) report that highlights alarming climate trends. The research suggests 2024 was likely the hottest year on record and the first to surpass an average global temperature increase of 1.5°C above pre-industrial levels.
In its annual climate assessment, the UN’s World Meteorological Organization (WMO) warned that human-induced climate change had “reached new heights” in 2024. Record greenhouse gas emissions, coupled with the El Niño weather phenomenon, contributed to extreme global temperatures.
“Our planet is issuing more distress signals,” stated UN Secretary-General António Guterres, urging world leaders to take more decisive climate action. His plea followed a controversial move by President Donald Trump, who withdrew the United States from the Paris Agreement for the second time, raising concerns about international climate cooperation.
According to the WMO, the global average surface temperature in 2024 was 1.55°C above the 1850-1900 baseline, with a margin of uncertainty of 0.13°C. This marked the warmest year in a 175-year observational record. Extreme weather intensified, with at least 151 unprecedented climate disasters recorded worldwide, including severe storms, heatwaves, floods, and droughts.
Stefan Rahmstorf, head of research at the Potsdam Institute for Climate Impact Research, stressed the urgent need for action. “Millions of people are suffering the consequences of climate change. We can only stop the warming trend by moving away from fossil fuels—and we must do it fast. Ignoring reality and silencing scientists will only lead to harm, and ordinary people will bear the cost.”
While a single year surpassing 1.5°C does not technically violate the Paris Agreement’s long-term temperature limit, the report warns that global warming has accelerated significantly in recent years. The current warming trend now stands between 1.34-1.41°C above pre-industrial levels, up from the 1.1°C recorded in 2020.
Celeste Saulo, WMO Secretary-General, emphasized that while the breach is temporary, it serves as a critical warning. “This is a wake-up call. Every fraction of a degree of warming increases risks to lives, economies, and ecosystems.”
The report also highlighted the devastating effects of climate change on the world’s oceans. Sea temperatures reached record highs for the eighth consecutive year in 2024, warming twice as fast as they did before 2005. Rising sea levels are now advancing at double the rate recorded three decades ago, and scientists predict it could take hundreds to thousands of years to reverse these trends.
Additionally, the cryosphere—Earth’s frozen regions—is melting at an alarming rate. Between 2022 and 2024, glacier loss reached record levels. In February 2024, Arctic sea ice plummeted to a historic low.
Carbon dioxide levels also saw a sharp increase, reaching 420 parts per million (ppm) in 2023—the last year with finalized data. This represents a 2.3 ppm increase from the previous year and a stark contrast to pre-industrial levels of 280 ppm.
As climate scientists and global leaders digest these findings, the urgency to take action has never been greater. The challenge ahead remains immense, but experts stress that aggressive policy measures, rapid reduction of fossil fuel use, and innovative climate solutions are necessary to mitigate further damage.
