A concerning new study finds that forests nationwide are suffering under the weight of drought and climate change, and things are only likely to get worse.

Scientists from 14 research institutions, led by Duke University environmental scientists James Clark, wrote that in the past two decades, global warming has increased the severity of forest droughts across the United States, according to a Duke statement. The findings were published in the journal Global Change Biology.

“Over the last two decades, warming temperatures and variable precipitation have increased the severity of forest droughts across much of the continental United States,” Clark said in the statement. “While the effects have been most pronounced in the West, our analysis shows virtually that all U.S. forests are now experiencing change and are vulnerable to future declines.”

Drought is already a huge problem in the West, where it has become a statewide emergency in California. Entire communities of trees have died from drought, and bark beetle infestations and wildfires are taking a toll as well. And the droughts are expected to only get worse and more prolonged across the rest of the United States.

“Prolonged drought affects wildfire risks, species distribution, forest biodiversity and productivity, and virtually all goods and services provided by forests, so there is a pressing need to know what is happening now, what might happen in the future and how we can manage for these changes,” Clark added.

Drought is one of the many numerous negative affects on the planet expected due to climate change, scientists say. They also warn of more violent storms, rising sea levels leading to flooding, and the extinction of a multitude of species.