CLIMATE CHANGE is expanding the FOREST DESTROYING BEETLE infestation.

The Mountain Pine Beetles were historically contained to the pine forests west of the Canadian Rockies, which had adapted to the insects’ presence. Their ability to spread and reproduce is heavily effected by temperature: as the climate warmed, cyclical cold snaps killed off less and less of the population. They dispersed over greater geographic areas.

http://thinkprogress.org/climate/2013/04/11/1855211/climate-change-keeps-expanding-canadas-unprecedented-epidemic-of-forest-destroying-beetles/