Chasing a Climate Deal in Paris

World leaders have 12 days to agree on plans to slow global warming. We’re weighing in with insights and analysis.

Mountain pine beetles can infect and kill acres of pine forests. Credit David Ryder/Bloomberg, via Getty Images

What Climate Change Looks Like: Dying Pine Forests

This week, we’re featuring images that show how global warming has already impacted the world.

Bark beetles have been boring into and killing trees in western North America for ages, and have evolved to be an important part of the forest ecosystem, culling weaker trees to make room for younger ones. But as the climate has changed, the tiny pests’ killing ways have gotten out of control. Warmer temperatures – a few degrees Fahrenheit higher, on average, in some locations – over the past few decades have meant that more of the bugs’ larvae have survived winter, helping infestations spread across thousands of acres of Western pine forests, like this one near Whitecourt in the Canadian province of Alberta. Warmer temperatures have also allowed the bugs to thrive at higher elevations, where they infest different tree species, like whitebark pines, that have not evolved defenses against them.