By Deborah Bloom, Brad Brooks

PORTLAND, Ore. (Reuters) – Fire crews have fended off a blaze threatening the historic Mount Wilson Observatory, as wildfires of unprecedented scope in the U.S. West spread smoke across the nation and even into Europe on Wednesday.

Dozens of fires have burned some 4.5 million acres (1.8 million hectares) in Oregon, California, and Washington state since August, ravaging several small towns, destroying thousands of homes, and killing at least 34 people.

The fires have thrust a debate about climate change to the forefront of the election, with President Donald Trump downplaying the role a warming planet could have in the devastation during a visit to California this week, and his Democratic challenger Joe Biden calling Trump a “climate arsonist” and ignoring a “central crisis” facing the nation.Fire officials say the Bobcat Fire, which has been burning an area of national forest northeast of Los Angeles since September was no longer an immediate threat to incinerate the Mount Wilson Observatory.

“I was telling people yesterday (Tuesday) that the defense of the Mount Wilson observatory was taking on the feel of a mini-Alamo,” John Clearwater, public affairs officer for Angeles National Forest, told Reuters.

Twelve firefighting crews worked to protect the site, and planes flew within 500 feet of it to fight the blaze. “It would have been devastating if we had lost that observatory,” he said.

But the blaze was still only at 3% containment and behaving erratically, fire officials say, and authorities have ordered evacuations in the area.

The West Coast wildfires, which officials and scientists have described as unprecedented in scope and ferocity, have filled the region’s skies with smoke and soot, compounding a public health crisis already posed by the coronavirus pandemic.

Scientists tracked the smoke as far away as Europe. The European Union’s Copernicus Atmosphere Monitoring Service (CAMS) is monitoring the scale and intensity of the fires and the transport of their smoke across the United States and beyond.

“The fact that these fires are emitting so much pollution into the atmosphere that we can still see thick smoke over 8,000 kilometers (4,970 miles) away reflects just how devastating they have been in their magnitude and duration,” CAMS Senior Scientist Mark Parrington said in a statement.

Source: Reuters