Wrangell Sentinel -

Canada`s worst-ever wildfire season has choked much of North America with dangerous smoke for months, coupling with deadly heat around the globe in a summer that`s focusing the world`s attention on the perils of climate change.

By last week, some 42,000 square miles had burned in Canada — half again more than the entire Tongass National Forest in Southeast Alaska. About 900 fires were actively burning, with only about one-fifth considered under control.

“I watch this pretty much 24/7,” Mark Smith, the air quality meteorologist for the Alaska Department of Environmental Conservation, told the C...