The Earth’s climate system reached new levels of stress in 2025, with rising temperatures, record greenhouse gas concentrations, and rapidly warming oceans signalling an accelerating climate crisis, according to a new report by the World Meteorological Organization.
The State of the Global Climate 2025 report paints a stark picture of a planet undergoing widespread and interconnected changes, corroborating that global warming is no longer a distant threat but a present and intensifying reality.
According to the report, global temperatures in 2025 were about 1.43°C above pre-industrial levels, placing the year among the hottest ever recorded. The past eleven years, from 2015 to 2025, now rank as the warmest period in modern history.
At the same time, atmospheric carbon dioxide concentrations climbed to 423.9 parts per million, the highest level in at least two million years. Other greenhouse gases, including methane and nitrous oxide, also reached record highs.
The report said this continued rise is largely driven by fossil fuel use, wildfire emissions, and weakening natural carbon sinks. Nearly half of all human-emitted CO₂ remains in the atmosphere, intensifying the greenhouse effect.
A key concern highlighted in the report is the Earth’s growing energy imbalance, which is increasing at a rate of about 0.3 watts per square metre per decade. This imbalance reflects the excess heat being trapped in the climate system.
In the report, experts said oceans are absorbing the vast majority of this excess heat, estimating that about 91 per cent is stored in ocean waters. As a result, ocean warming over the past two decades has occurred at more than twice the historical rate.
This rapid warming is already having widespread consequences. Nearly 90 per cent of the global ocean surface experienced marine heatwaves in 2025, disrupting ecosystems, damaging fisheries, and intensifying extreme weather events.
Sea levels are also rising at an accelerating pace. Since satellite measurements began in 1993, global mean sea level has increased by about 11 centimetres, with the rate of rise nearly doubling in recent years. Coastal communities, especially in low-lying regions, face growing risks from flooding, erosion, and saltwater intrusion.
The planet’s frozen regions are also in rapid decline. Glaciers continue to lose mass at alarming rates, with eight of the ten worst years for glacier loss occurring since 2016. Meanwhile, Arctic sea ice remains near record lows, reducing the Earth’s ability to reflect sunlight and further accelerating warming.
In addition to heating, the oceans are becoming more acidic. Around 29 per cent of human-emitted CO₂ is absorbed by the oceans, causing a steady decline in pH levels.
Scientists warned that this chemical shift threatens coral reefs, shellfish, and marine ecosystems that millions of people depend on.
The report emphasised that these changes are deeply interconnected. Rising temperatures drive ice melt and sea-level rise, while ocean warming fuels stronger storms and disrupts weather patterns globally.
Scientists also warned of growing impacts on human life, including increased heatwaves, floods, and droughts. These events are already contributing to food insecurity, displacement, and economic losses, particularly in vulnerable regions.
“The climate system is clearly out of balance,” the report concludes, stressing that the accumulation of heat across the planet will have long-lasting consequences.
The findings underscore the urgent need for stronger climate action, improved early warning systems, and policies aimed at reducing emissions and protecting communities from the accelerating impacts of climate change.