Explaining the link between climate change and pine bark beetles

“On one hand, I’m gonna tell you, ‘This is no big deal, bark beetles have been around for 35 million years, conifers have been around for a lot longer than that, and bark beetles have been killing conifers for 35 million years. There have been epidemics every 30 to 70 years. This is no big deal.’

“Then, on the other hand, I’m gonna tell you, ‘Holy smokes guys, this has never been seen before. Yes, it’s an epidemic, yes, epidemics are natural, but never has there been an epidemic like this as far as biologists have been able to look into the past.”

Professor Jeff Mitton begins his community programs with these statements as he introduces his research findings about the pine bark beetle and the link between climate change and this unprecedented epidemic.

Mitton, a professor of ecology and evolutionary biology, has been discussing the beetle epidemic in Colorado towns and visiting area schools this year as part of CU-Boulder’s Learn More About Climate Initiative. The broader goal of the initiative is to inform Coloradans about how climate change is already impacting the state.

The epidemic stretches from the Sangre de Cristo mountains in New Mexico up to the Yukon Territories, almost to Alaska. It extends from the edge of the Great Plains to the Pacific Ocean, impacting an area approximately 1,500 miles by 900 miles.

Mitton has found that some beetles are producing two generations of offspring in one season, a dramatic increase from traditional beetle development of one generation per season.

“Climate change has also contributed to this epidemic by speeding beetle development and increasing their reproductive output,” said Mitton.