It's been a brutal year for wildfires in the Pacific Northwest, and the U.S. Forest Service says humans are mostly to blame.

Thirty of the blazes that firefighters in Oregon and Washington responded to last week were started by illegal burns or faulty car exhaust systems, according to a KATU News report.

At least one—which started Thursday in West Linn—was sparked by a man's attempt to get rid of a yellow jacket nest by mixing gasoline and oil and lighting it up, KGW-TV first reported.

A brush fire ignited quickly and scorched four surrounding acres.

"Because of the nature of our work," Tualatin Valley Fire Marshal Steve Forster told KGW, "we uniquely, understand the incredible speed at which fire can spread, but I believe most people are unaware of the potential destruction fire can cause."

So far this year, 71 percent of the wildfires in Oregon and Washington have been human-started. And in Oregon alone, there is currently almost as much land on fire—185,457 acres—as burned in all of 2016.

The Forest Service is calling in backup. On Tuesday, the agency flew in firefighters from Australia and New Zealand to help manage the region's blazes.

We could use the extra help.

According to the National Interagency Fire Center, the Pacific Northwest is also currently at higher risk for forest fires than almost any other region in the U.S.