Earth's climate more unbalanced than ever, WMO warns

Every person alive today has grown up in a world of worsening weather extremes. Last year, a 50-year flood swamped Texas, glaciers in Iceland melted at record speed, a hurricane struck Jamaica with near-unprecedented force, and the world sweltered through record heat. The window to change course is narrowing fast, warn scientists.

According to DW, a report published Monday by the World Meteorological Organization (WMO) confirms the Earth's climate is more out of balance than at any point in observed history — and that the consequences will reverberate for centuries, and potentially millennia.

Key findings in the annual WMO State of the Global Climate 2025 report include:

2015 to 2025 was the hottest decade on record

Oceans reached unprecedented heat for the ninth year running

Glaciers and sea ice continue their retreat

Extreme weather, cascading health risks and mounting human costs

Earth's energy imbalance hits an all-time high, which means more of the sun's energy is entering the planet's systems than is leaving

Global mean sea level is rising at a faster rate since 2012 than in the preceding two decades.

"Every key climate indicator is flashing red," said UN Secretary-General Antonio Guterres. "Humanity has just endured the 11 hottest years on record. When history repeats itself 11 times, it is no longer a coincidence. It is a call to act."

Rising heat, extreme weather and global instability

Depending on the data set used, last year ranked second or third hottest on record at approximately 1.43 degrees Celsius (2.57 Fahrenheit) above pre-industrial levels. That was slightly below the 2024 record of 1.55 C. The dip was due to global weather phenomenon La Nina's temporary cooling influence.

Under the 2015 Paris Agreement, countries agreed to cap warming at 2 C and ideally 1.5 C to avoid the worst impacts of planetary heating.

The key driver of rising temperatures is surging greenhouse gas concentrations in the atmosphere, largely caused by burning oil, coal, and gas. Carbon dioxide (CO2) reached its highest atmospheric level in at least 2 million years in 2024, and continued rising in 2025, according to the report.

The findings carry particular urgency for the year ahead. The warming weather pattern El Nino could return later this year, which scientists say could drive another sharp temperature increase, fueling more extreme weather.

In 2025, heatwaves, wildfires, flooding, drought and tropical cyclones caused thousands of deaths and billions in economic losses. The California wildfires in January 2025 alone caused more than $60 billion (€52.4 billion) in damage and were the costliest such event ever recorded.

The report underlined climate change's growing health toll, including dengue fever — now the world's fastest-growing mosquito-borne disease. Meanwhile, 1.2 billion workers, over a third of the global workforce, are exposed to dangerous heat each year.

Climate change is also driving hunger, migration and water scarcity, increasing competition over dwindling resources. Over the past decade, weather-related disasters have forced 250 million people to leave their homes.

The UN has drawn a direct line between the climate crisis and global instability. At the same time, war and militaries themselves are a significant contributor to planet-warming emissions.

"Our addiction to fossil fuels is destabilizing both the climate and global security," UN Secretary-General Antonio Guterres said in a statement.

Guterres added that countries have to act quickly to decarbonize to stop further warming, and accelerate a transition to renewable energy. "Renewables deliver climate security, energy security and national security," he said.