california trees dying
© U.S. Forest ServiceAn aerial detection survey photo of dead and dying trees on the Sequoia and Sierra national forests in August 2016.
A new aerial survey has identified an additional 36 million trees have died across California since the last count conducted in May, according to a release from the U.S. Department of Agriculture. That brings the total of dead trees spotted since 2010 to more than 102 million — 62 million died in 2016 alone, a 100 percent increase over 2015.

The statement identifies the following causes:
  • Five consecutive years of severe drought in California
  • A dramatic rise in bark beetle infestation
  • Warmer temperatures
The U.S. Forest Service is also having to use more of its resources fight wildfires rather than restoring forests, according to the release. Fire management rose to 56 percent of the Forest Service's budget last year and is expected to hit 67 percent of the budget in 2025. At the same time, dead and dying trees increase wildfire risk, Agriculture Secretary Tom Vilsack said in the release.

california drought dying trees
© U.S. Forest ServiceDead trees along a mountain road on the Sequoia National Forest in May 2016.
"USDA has made restoration work and the removal of excess fuels a top priority, but until Congress passes a permanent fix to the fire budget, we can't break this cycle of diverting funds away from restoration work to fight the immediate threat of the large unpredictable fires caused by the fuel buildups themselves," Vilsack said.

The majority of the dead trees are in the southern and central Sierra Nevada region, according to the release. But there's also been a rise in the number of dead trees in the northern part of the state.

"We must fund wildfire suppression like other natural disasters in the country," Vilsack said.

The release notes that California has had a record wildfire season, with the Blue Cut fire burning 30,000 acres and more than 120,000 acres burning this fall in the southeastern United States.