Because global warming has allowed pine beetles to survive the winter, their populations have boomed and in the past few years they have killed off millions of acres of forest -- billions of trees -- in the British Columbia and the Mountain West.
If making wildfires more dangerous and reducing the amount of carbon that is safely stored in these forests wasn't worrisome enough, now Katie Valentine at Think Progress notes another of the myriad ripple effects caused by these beetles: BEAR ATTACKS!
Whitebark pine trees, whose nuts are an important late-summer and fall food source for grizzly and black bears, have been killed by the thousands in recent years by mountain pine beetles, whose populations have exploded and range expanded with the onset of warmer weather and milder winters.
Lack of whitebark pine seeds are driving bears to seek nourishment in more highly-populated tourist areas of the park, and in recent years, several bear attacks on visitors have been recorded near and around Yellowstone. In 2010, Wyoming had a record 251 bear-human “conflicts,” which include attacks on people, livestock and property.
“We are expecting an increase in human-bear encounters and we are reinforcing safety messages,” Yellowstone spokesman Al Nash said this week.
Valentine also notes that it isn't just the pine seeds that are missing. Trout and even animal carcasses are harder to come by these days due to warmer weather. Read the rest.
Of course, it isn't the fault of the bears that we've warmed the atmosphere and helped kill off their food sources. So if you're in bear country, be smart, carry bear spray and try to avoid an encounter by hiking in groups.
UPDATE: As Jaymi noted earlier, the way you handle grizzly bears is different than black bears. So it doesn't hurt to know what kind of bears live in the area you'll be hiking or camping and learn both techniques.