With the California wildfires scorching over 4 million acres this year—an unprecedented level of disaster—it stands to reason that some new verbiage would be needed to express the magnitude of the threat. That’s why you’ll be hearing the term gigafire.

The blaze known as the August Complex ravaging California is now being classified as a gigafire, a fire that destroys 1 million acres of land. It surpasses the term megafire, a fire that consumes over 100,000 acres.

The August Complex, which began with a series of lightning strikes, is the state’s first-ever gigafire, though not the country’s. In 2004, the Taylor Complex in Alaska destroyed 1.3 million acres. In 1988, the Yellowstone Fire took 1.58 million acres in Montana in Idaho.

A complex is often used to describe a group of smaller fires which may or may not begin to burn together. The August Complex began as 300 individual fires that eventually joined together.

The term gigafire is thought to have originated in the comments section of the Wildfire Today website. In 2017, a visitor to the site with the screenname “kevin9” proposed that fires consuming over 1 million acres should be dubbed gigafires. The site began using the term for wildfires that met or exceeded that threshold in Australia.

The record-setting wildfire destruction this year is thought to be exacerbated by climate change, with hotter and drier conditions providing an ideal setting for fires to take hold and spread. As of Monday, firefighters had contained roughly 65 percent of the California blaze.

[h/t CNN]