2025 Ranked as One of World’s Hottest Years Due to Human-Made Climate Crisis

A new analysis of the world’s climate in 2025 finds that this year was one of the three hottest ever recorded, demonstrating that the threat posed by the human-made climate crisis is not going away anytime soon.

The analysis by World Weather Attribution (WWA), an organization that examines the likelihood that the climate crisis played a role in severe weather events, also shows that, over the past three years, the world has exceeded the 1.5 degrees Celsius global increase limit outlined in the 2015 Paris Agreement.

Temperatures remained high this year, despite the presence of the La Niña weather phenomenon in the Pacific Ocean, which typically cools those waters whenever it occurs.

Overall, the WWA report published on Tuesday documented 157 extreme weather events throughout 2025, defined as an event that either causes more than 100 deaths in a given area, detrimentally affects more than half that area’s population, or results in a state of emergency being declared.

Friederike Otto, a co-founder of WWA and a professor of climate science at the Imperial College of London, said the climate crisis and humanity’s role in exacerbating it could not be debated.

“Each year, the risks of climate change become less hypothetical and more brutal reality,” Otto said.

The deadliest type of event documented this year was heat waves, accounting for nearly a third of the total extreme weather events WWA observed. According to the organization, the climate crisis made heat waves 10 times more likely this past year than they were a decade ago.

“The heat waves we have observed this year are quite common events in our climate today, but they would have been almost impossible to occur without human-induced climate change,” Otto explained.

WWA called for rapid and deep reductions in the use of fossil fuels, stating that extreme weather will continue to intensify without immediate changes.

Globally, the world isn’t doing enough to slow, let alone reverse, the trend. China, for example, is investing in renewable energy sources, but also still heavily invests in coal. And in the U.S., the Trump administration is ending once-planned renewable energy projects in favor of fossil fuels.

“A lot of policymakers [are] very clearly making policies for the interest of the fossil fuel industry rather than for the populations of their countries,” Otto opined.

Beyond rising water levels and more frequent and deadly wildfires, floods, heatwaves, droughts, hurricanes, and tornadoes, the climate crisis may also bring about an unexpected increase in volcanic activity.

According to a CNN report, scientists in Iceland are currently investigating whether receding glacial ice in that country could affect magma that is deep underground. According to a decades-old theory, the reduction of glaciers lessens pressure underground, allowing for more magma to be produced and reach its way to the surface, including in the form of volcanic eruptions.

Researchers from Brown University have run computer models, based on data they have analyzed, and estimate that at least twice as much magma is being produced in Iceland due to melting glaciers.

Pablo Moreno-Yaeger, a researcher at the University of Wisconsin-Madison, is studying the same concept in Chile, examining crystals in erupted rocks from thousands of years ago. According to Moreno-Yaeger’s research, eruptions became more frequent as glaciers in that region began retreating.

Applying that idea to today, melting glaciers could, theoretically, result in more volcanic eruptions around the world — which could make the climate crisis even worse. Receding glaciers could “trigger eruptions, and the eruptions in turn could contribute to further warming and melting” through the continued buildup of more greenhouse gases in Earth’s atmosphere from those eruptions, Moreno-Yaeger explained.