The beetle, not much bigger than a bedbug, is native to the West and has always been known as a tree killer. For centuries it has killed a few diseased trees here, a patch of trees there, but never before has it caused destruction on the scale being seen today.

U.S. Forest Service scientist Jesse Logan and other forest researchers have discovered that the beetles are responding to higher average temperatures by breeding almost nonstop. They are no longer being held in balance by the lower winter temperatures that once prevailed.

The death of so many trees, which imperils the habitat of animals and threatens catastrophic forest fires, is further evidence that the planet is warming at an alarming rate. Appearing on a National Public Radio show this week, Logan said the warming is not part of a natural cycle, as many climate-change deniers insist. “It is directly our actions that are taking these forests out,” Logan said.

Scientists around the world agree with Logan: Human activity, principally the burning of fossil fuels for energy, is responsible for rapidly accelerating warming. Worldwide consequences include the melting of polar ice and weird weather, including shorter springs and extended summers that cause droughts.

That is why Congress is nearing debate on a climate-change bill that would cap the emissions of greenhouse gases from American industries and set goals for converting to non-emitting power sources such as solar and wind. Greenhouse gases, such as carbon dioxide, trap heat in the atmosphere that would otherwise escape harmlessly into space.

It is imperative to pass this bill so more and bigger changes in energy production can start immediately. Those who deny the urgency should take a drive through the West.

“The fanatic is not really a stickler to principle. He embraces a cause not primarily because of its justness or holiness but because of his desperate need for something to hold onto.” - Eric Hoffer