Experts say saltwater isn’t a fire department’s first choice, but is sometimes necessary to battle out-of-control flames. (Daniel Sparks via Storyful)

Desperate California firefighters are using water from the Pacific Ocean to extinguish the ongoing wildfires in Los Angeles County.

For 30 years, the aircraft have been part of California's fire defenses. In a warming world, these types of cross-border deals will become more important.

In the skies above Los Angeles, air tankers and helicopters silhouetted by the setting California sun dart in and out of giant wildfire plumes, dropping much-needed flame retardant and precious water onto the angry fires below.

The fight from above is critical in giving firefighters a chance to get some semblance of control over the fires, said one fire chief.