When wildfires began raging across France and Spain last month, the European Union sent aircraft and firefighters from nine other countries. The Pacific Northwest, where fires have forced tens of thousands to evacuate, has landed help from Australia and New Zealand.

Wildland firefighters have increasingly shared resources across borders, sending personnel and equipment to help in severe fire seasons. The trend is driven partly by climate change worsening wildfires, experts say. But now, wildfire seasons are becoming so bad they are stressing governments’ ability to share resources when they’re needed most.

“There’s more international cooperation happening, but it’s a double-edged sword because there’s more competition,” said Cordy Tymstra, a wildfire scientist and consultant in Canada. Just in the last month, out-of-control fires have torn through multiple countries and regions that typically send help to each other, he said. “There’s only so many resources, and the level of resourcing hasn’t risen commensurate with the need.”

Tymstra and other experts say increased reliance on international sharing over the last couple of decades helped close the gap as fire seasons intensified. But increasingly, it’s also revealing that firefighting capacity has failed to keep pace with climate change.

Wildfires now burn more than twice as much area annually as they did 20 years ago, according to data from the University of Maryland. Four of the five worst wildfire years this century have come since 2021.

Last year was Europe’s most destructive, but 31 percent more area has burned so far this year compared to the same period in 2025. Those fires have forced one of the largest evacuations in Europe since World War II.

In Spokane, fires have destroyed hundreds of homes and prompted comparison to a “war zone.” Across the United States, some 5.7 million acres have burned so far this year, more than all of 2025.

Canada had its second-worst season last year, trailing 2023. And new research is finding that reductions in pollution from vehicles, power plants and factories is being offset by increased wildfire smoke, which a study suggests is now a bigger health threat to babies in the womb.

Read the full article about international cooperation to fight wildfires by Nicholas Kusnetz at Inside Climate News.