The oceans have broken heat records for nine years in a row, glaciers are retreating, extreme weather is killing thousands. The only way to avoid the worst is to immediately abandon fossil fuels.
We live in a world where extreme weather events are getting worse. Last year, 50-year floods hit Texas, Iceland's glaciers melted at a record rate, a hurricane hit Jamaica with almost unprecedented force, and the world was scorched by record-breaking heatwaves. Scientists warn that there is little time left to change course.
A report released Monday by the World Meteorological Organization (WMO) confirms that the Earth's climate is more unbalanced than ever before and that the consequences will continue for centuries, and quite possibly, millennia.
Key findings in the WMO's annual State of the Global Climate report for 2025 include:
-Oceans reached unprecedented warmth for ninth consecutive year
-Glaciers and sea ice continue to retreat
-Extreme weather, health risks and increasing human costs
-The energy imbalance on Earth has reached a record level, meaning that more solar energy is entering planetary systems than is leaving.
- Since 2012, global average sea level has been rising at the fastest rate in the last two decades
"Every key climate indicator has moved to red status," said UN Secretary-General Antonio Guterres.
"Humanity has experienced the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to action."
Rising heat, extreme weather and global instability
Depending on the data used, last year ranked as the second or third warmest on record, at about 1.43 degrees Celsius above pre-industrial levels. The data was slightly lower than the record set in 2024, which was 1.55 degrees Celsius. The drop was due to the temporary cooling effect of the global weather phenomenon known as "La Nina."
Under the 2015 Paris Climate Agreement, countries agreed to limit global warming to 2 degrees Celsius and, in the most ideal scenario, to 1.5 degrees Celsius, to avoid the worst impacts of planetary warming.
The main factor driving the rise in temperatures is rising concentrations of greenhouse gases in the atmosphere, largely caused by the burning of oil, coal and gas. Carbon dioxide (CO2) reached its highest atmospheric level in 2024 and continued to rise in 2025, according to the report.
The findings carry particular urgency for the coming year. "El Nino," the warming weather pattern, could return later this year, which scientists fear could cause temperatures to rise significantly, triggering more extreme weather.
In 2025, heat waves, wildfires, floods, droughts and tropical cyclones caused thousands of deaths and billions of dollars in economic losses. The fires in California alone, in January 2025, caused more than $60 billion (€52.4 billion) in damage and were the costliest event ever recorded.
The report highlighted the growing impact of climate change on health, including dengue fever, the world's fastest-growing mosquito-borne disease. Meanwhile, 1.2 billion workers, over a third of the global workforce, are exposed to extreme and dangerous heat every year.
Climate change is also driving hunger, migration and water scarcity, increasing competition for dwindling water resources. Over the past decade, natural disasters have forced 250 million people from their homes.
The UN has made a direct distinction between the climate crisis and global instability. At the same time, war and militaries themselves are a significant contributor to the emissions that cause global warming.
"Our dependence on fossil fuels is destabilizing both the climate and security," UN Secretary-General Antonio Guterres said in a statement.
Guterres added that countries must "race" quickly towards decarbonization, to stop further warming and accelerate the transition to renewable energy.
"Renewable energies provide climate security, energy security and national security," he said.
Earth's energy is out of control: what does this mean?
Appearing for the first time as an indicator in the OBM report, the Earth's energy imbalance - the gap between solar energy entering the atmosphere and heat escaping back into space - reached a record level in 2025. In a stable climate, the incoming and outgoing energy from the sun are the same.
In today's climate, much more energy enters than leaves, because greenhouse gases act like "blankets around the planet," trapping excess heat in all of its systems. About 91% is absorbed by the oceans, 5% by land, 3% by ice sheets and glaciers, and 1% warms the atmosphere.
"Human activities are increasingly disrupting the natural balance, and we will live with these consequences for hundreds and thousands of years," said UN Secretary-General Celeste Saulo.
Accelerated warming: consequences for the oceans
The oceans are the planet's main source of heat energy and protect life on Earth from the worst impacts of climate change. But ocean heat broke records again in 2025, for the ninth consecutive year, with 90% of the ocean surface experiencing at least one marine heatwave, despite the cooling of "La Nina."
The report's authors said there were no signs of the heat sink weakening, but they stressed that warming was increasing in all layers of the ocean, including the deep.
The human cost of warming oceans is huge. Some 3 billion people rely on seafood for protein, yet rising temperatures are bleaching corals, decimating fish populations and weakening the ocean's ability to absorb carbon dioxide. Warmer seas are also fueling more powerful storms and accelerating the loss of ice at both poles, fueling sea level rise, with cities and coastal areas on the front lines.
Arctic and Antarctic sea ice was at its lowest level on record, while glacier mass loss was among the five worst years since records began in 1979. Glaciers are essential for the water supply of two billion people. "With today's observations we are not just predicting the weather, we are protecting tomorrow. Those who will live in the future. The planet of tomorrow," said Celeste Saulo of the World Meteorological Organization. / DW