Climate Change and the Pine Beetle

The MPB’s populations have always been kept under control during winter freezes and generally cool temperatures year-round. The Larvae cannot survive any temperature under -40 *C, and are typically killed off when the coldest weather of the winter months surround.

Orange: Beetle spread from 2002-2006
Red: Beetle spread from 2007-2011
(Natural Resources Canada 2014)

Unfortunately, winters have been abnormally warm, and temperatures have not reached a point that would contain the population. This has allowed pine beetle numbers to show massive escalation. Increasingly warmer and drier summer months also aids higher rates of productivity and procreation (Creeden 2014).


This explosion has been most detrimental in the Canadian region. Forests there are particularly evolved to depend on the winter freeze to keep the MPB numbers within reason.




In addition to an unmanageable increase in numbers, the increasing temperatures have caused the MPB to spread North. These forests are not evolved for disturbances from beetles as they burst forth (Taylor 2007).

(The MPB’s invasion into new forest areas has transformed the beetle from a natural disturbance to an invasive threat).

Healthy forests are carbon sinks, absorbing excess carbon over their lifespan, and aiding in the reduction of excess carbon, thus dampening the rate of climate change. But when trees die and degrade, more carbon is released into the atmosphere, creating an unbalanced gas exchange. (Kurtz 2008).

With the MPB destroying large areas of forests in short time spans, the forests have now gone from carbon sinks to sources. The released carbon increases the effects on climate change, elevates winter temperatures, and further aids in the expansion and success of the MPB's forces.

Novel flow diagram showing the positive feedback relationship between the Mountain Pine Beetle population boom and Climate Change (Mitton 2012), (Spross 2013). 

What is the full effect of these beetles on the atmosphere? This is still relatively unclear. The MPB's effect on tree carbon cycles are not taken into account in many models of global climate change over the years (Six 2012).