Extreme wildfires have destroyed about one-fifth of all giant sequoia trees. To safeguard their future, the National Park Service is planting seedlings that could better survive a hotter climate.

Firefighters are proactively working to protect the giant trees by deploying a ground sprinkler system and clearing any materials that could fuel the fire.

The world's largest trees are adapted to wildfires. But with fires getting more extreme, scientists warn that giant sequoias are running out of time.