Global Warming Effects Around the World

British Columbia, Canada

Top Impact

Ecosystems (Land)

Other Impacts

Temperature (Air)

People (Costs)

Trees destroyed by mountain pine beetle in British Columbia, Canada

Dead trees stretch as far as the eye can see in Prince George, British Columbia. Because of slightly warmer temperatures, the mountain pine beetle has survived harsh winters in the mountains of the province, attacking more than 43 million acres (17.5 million hectares) of forest and killing millions of trees. That area is larger than all of New England.1

Key Facts

The mountain pine beetle's ability to survive and multiply rapidly is highly sensitive to temperature2,3 and precipitation.4

  • Temperatures in the interior mountain ranges of British Columbia have risen faster than the global average, particularly during the winter.5,6
  • By 2010 the mountain pine beetle had killed almost 24.5 billion cubic feet (692 million cubic meters) of timber since scientists began tracking the infestation in 1999.7 That is more than nine times the allowable annual timber cut in British Columbia.8
  • The beetles have now managed to cross the Continental Divide, threatening the jack pine forests that reach across the continent to the East Coast of Canada and the United States.9,10
  • By killing off millions of acres of trees, the mountain pine beetle has turned infested lodgepole pine forests into a source of atmospheric carbon as the trees decay.11

Details

The mountain pine beetle epidemic in British Columbia, which began in 1999, has already killed more than half of the province's mature, marketable pine trees.7 When conditions are right, pine beetles can multiply rapidly, devastating large areas of forest. Mountain pine beetles bore through the bark of pine trees, killing the tree. Their preferred host is mature lodgepole pine. However, they can also attack younger lodgepole pines, jack pines, ponderosa pines, and western white pines.12

The mountain pine beetle's ability to survive and thrive is highly sensitive to temperature and precipitation. Outbreaks have been correlated with slightly warmer winter temperatures, which allow more beetles to survive.2 In one study of higher elevations, biologists found that warmer temperatures allow the pine beetles to complete a full generation in just one year instead of two, allowing the population to grow faster.3 And recent periods of drought have stressed trees, making them more susceptible to attack.4

Over the past decade, British Columbia has not had enough extreme cold to kill off the bark beetles—a welcome check on beetle populations in the past. Along the coast of British Columbia, the warming trend has been similar to the global trend.5,6 However, in the mountainous interior and northern regions of the province, including the areas hardest–hit by the beetle outbreak, the warming trend has been much steeper than the global trend, particularly in winter.5,6

The mountain pine beetle has attacked more than 43 million acres (17.5 million hectares) of forest, killing millions of trees.13 That is an area larger than all of New England.14 The population of mountain pine beetles is now in decline because the beetle has killed off most of its preferred host—the lodgepole pine—in areas where the beetle can overwinter.12 It is now most active in the northern part of its range, and to the east of the main outbreak area, which includes higher elevations and the province of Alberta.15

British Columbia's Ministry of Forests estimates that the mountain pine beetle has killed almost 25 billion cubic feet (700 million cubic meters) of timber since this infestation began.13 That is more than nine times the allowable annual timber cut in British Columbia.8 Timber is critical to the province's economy: forest products accounted for more than 30 percent of its exports in 2008.16

The Ministry of Forests increased the allowable annual cut in the regions hardest hit by the beetle, to allow foresters to salvage dead trees.17 However, over time the dead trees will rot, and will be usable only for less valuable forest products.17 Although the devastated areas are being replanted, the new trees will not be mature enough to harvest for 30 to 50 years.18 That means a gap in production for the forestry industry in regions hit by the beetle outbreak.17

Part of a Larger Pattern

The mountain pine beetle has managed to cross the high elevations of the Rockies and the Continental Divide into Alberta.9 Although that province has few lodgepole pines, the beetle's preferred host, jack pine forests—a closely related species—stretch from Alberta across the continent to the East Coast of the United States and Canada. Foresters have recently found that the beetle can survive and multiply in those trees as well.19

Epidemic outbreaks of the mountain pine beetle have also occurred throughout the western United States, primarily in Colorado, Wyoming, Montana, and Idaho.20 And outbreaks are growing in California, Oregon, Washington, South Dakota, and just recently Nebraska.21 The mountain pine beetle has wreaked devastation on a scale beyond that of most other forest pests. For instance, beetles attacked some 11.8 million acres (4.8 million hectares) of forests in the United States in 2009, and some 75 percent of those losses stemmed from the mountain pine beetle.20,22,23

What the Future Holds

The rate at which the pine beetle could move eastward across Canadian jack pine forests depends on the weather24—including high winds, which can blow the insect eastward, as occurred when the beetle crossed the Continental Divide9—and further warming.10

The mountain pine beetle is also expanding its range northward and into higher elevations. By 2013, foresters expect the beetle to have killed roughly 80 percent of the mature lodgepole pines in British Columbia.25 Scientists estimate that the beetle infestation in that province is likely to release up to 270 megatons of carbon into the atmosphere from 2000 to 2020.11 That is about twice as much carbon as Canada releases from all sources in a year.26

A healthy forest normally stores significant amounts of carbon. By killing off millions of acres of trees, which then decay or provide fuel for wildfires, the mountain pine beetle has instead turned lodgepole pine forests into a source of carbon emitted into the already overloaded atmosphere.11

The pine beetle epidemic shows how warming temperatures can lead to a problem that, in turn, causes temperatures to rise even further. Such an effect is an amplification—or positive feedback loop—of global warming. The additional carbon in the atmosphere warms mountain temperatures even further, which allows the beetles to continue to multiply and destroy more trees, which give off more carbon. The feedback loop continues until the preferred host trees are no longer prevalent.

Credits

Endnotes

  1. Photo: Ronald F. Billings, Texas Forest Service, Bugwood.org. Online at http://www.forestryimages.org/browse/detail.cfm?imgnum=2108058. Accessed December 21, 2011.
  2. Powell, J.A., and J.A. Logan. 2005. Insect seasonality: Circle map analysis of temperature–driven life cycles. Theoretical Population Biology 67:161–179. Online at http://ww.usu.edu/beetle/documents/Powell-Logan2005.pdf. Accessed August 16, 2011.
  3. Bentz B.J., and G. Schen–Langenheim. 2007. The mountain pine beetle and whitebark pine waltz: Has the music changed? Proceedings of a conference: Whitebark pine—A Pacific Coast perspective, E.M. Goheen, amd R.A. Sniezko, technical coordinators. R6–NR–FHP–2007–01. Portland, OR: U.S. Forest Service, Pacific Northwest Region. Online at http://www.treesearch.fs.fed.us/pubs/34086. Accessed June 30, 2011.
  4. Berg, E.E., J.D. Henry, C.L. Fastie, A.D. De Volder, and S.M. Matsuoka. 2006. Spruce beetle outbreaks on the Kenai Peninsula, Alaska, and Kluane National Park and Reserve, Yukon Territory: Relationship to summer temperatures and regional differences in disturbance regimes. Forest Ecology and Management 227:219–232. Online at http://www.sciencedirect.com/science/article/pii/S0378112706001599. Accessed August 16, 2011.
  5. Osborn, Liz. 2008. Seasonal temperature trends in Canada. Current Results Nexus. Online at http://www.currentresults.com/Weather-Extremes/Canada/trends-temperature-seasonal.php. Accessed July 7, 2011.
  6. Hansen, J., et al. 2006. Global temperature change. Proceedings of the National Academies of Science 103(39):14288–14293, doi: 10.1073/pnas.0606291103. Online at http://www.pnas.org/content/103/39/14288. Accessed July 7, 2011.
  7. Walton, A. 2011. Provincial–level projection of the current mountain pine beetle outbreak: Update of the infestation projection based on the 2010 provincial aerial overview of forest health and the BCMPB model (year 8). Victoria, BC: British Columbia Forest Service. Online at http://www.for.gov.bc.ca/hre/bcmpb/Year8.htm. Accessed August 16, 2011.
  8. Ministry of Forests, Lands and Natural Resource Operations. Current allowable annual cut (AAC) by timber supply areas and tree farm licensees: Forest analysis and inventory. Victoria, BC. Online at http://www.for.gov.bc.ca/hts/analysis.htm. Accessed December 21, 2011.
  9. Alberta Sustainable Resource Development. 2009. Beetle facts. Edmonton, AB. Online at http://www.mpb.alberta.ca/BeetleFacts.aspx. Accessed June 30, 2011.
  10. Cullingham, C.I., et al. 2011. Mountain pine beetle host–range expansion threatens the boreal forest. Molecular Ecology 20:2157–2171, doi: 10.1111/j.1365-294X.2011.05086.x. Online at http://onlinelibrary.wiley.com/doi/10.1111/j.1365-294X.2011.05086.x/full. Accessed June 30, 2011.
  11. Kurz, W.A., et al. 2008. Mountain pine beetle and forest carbon feedback to climate change. Nature 452:987–990, April 24, 2008. doi:10.1038/nature06777. Online at http://www.nature.com/nature/journal/v452/n7190/abs/nature06777.html. Accessed June 30, 2011.
  12. Westfall, J., and T. Ebata. 2010. 2010 summary of forest health conditions of British Columbia. Victoria, BC: Ministry of Forests, Mines and Lands. Online at http://www.for.gov.bc.ca/ftp/HFP/external/!publish/Aerial_Overview/2010/FH%20Conditions%202010.pdf. Accessed December 21, 2011.
  13. Ministry of Forests, Lands and Natural Resource Operations. 2011. Facts about B.C.'s Mountain Pine Beetle. Victoria, BC. Online at http://www.for.gov.bc.ca/hfp/mountain_pine_beetle/facts.htm. Accessed June 30, 2011.
  14. U.S. Census Bureau. State & county quick facts. Washington, DC. Online at http://quickfacts.census.gov/qfd/index.html. Accessed June 30, 2011.
  15. Maclauchlan, L. 2009. The mountain pine beetle story: Path of the outbreak and future opportunities. Mountain Pine Beetle and Water Management Workshop Proceedings. Online at http://www.forrex.org/program/water/PDFs/Workshops/MPB_Handout.pdf. Accessed June 30, 2011.
  16. Province of British Columbia. 2010. A guide to the BC economy and labour market: Forestry & logging. Victoria, BC. Online at http://www.guidetobceconomy.org/major_industries/foresty.htm. Accessed July 7, 2011.
  17. Burton, P.J. 2010. Striving for sustainability and resilience in the face of unprecedented change: The case of the mountain pine beetle outbreak in British Columbia. Sustainability (2):2403&nsash;2423, doi:10.3390/su2082403. Online at http://www.mdpi.com/2071-1050/2/8/2403/pdf. Accessed June 30, 2011.
  18. British Columbia Ministry of Forests, Timber Supply Branch. 2001. Timber supply review: Prince George timber supply area analysis report. Victoria, BC. As cited in Burton, P.J. 2010. Striving for sustainability and resilience in the face of unprecedented change: The case of the mountain pine beetle outbreak in British Columbia. Sustainability (2):2403–2423, doi: 10.3390/su2082403. Online at http://www.mdpi.com/2071-1050/2/8/2403/pdf. Accessed June 30, 2011.
  19. Alberta Sustainable Resource Development, Wildfire Information Unit. 2011. Jack pine and mountain pine beetle. MPB in Alberta, May. Online at http://www.mpb.alberta.ca/Beetlefacts/BeetleBulletin.aspx. Accessed June 30, 2011.
  20. Forest Health Technology Enterprise Team. 2009. Forest pest conditions, Regions 1, 2, 4, 5 and 6: Mountain pine beetle summary 2009. Online at http://www.foresthealth.info/portal/Flex/FPC. Accessed January 9, 2012.
  21. Man, G. 2010. Major forest insect and disease conditions in the United States: 2009 update—Forest health protection. Washington, DC: U.S. Forest Service, FS–952. Online at http://www.fs.fed.us/foresthealth/publications/ConditionsReport_09_final.pdf. Accessed July 6, 2011.
  22. U.S. Forest Service and Wyoming State Forestry Division 2011. Press release, January 11. Online at http://www.fs.usda.gov/wps/portal/fsinternet/!ut/p/c4/04_SB8K8xLLM9MSSzPy8xBz9CP0 os3gjAwhwtDDw9_AI8zPyhQoY6BdkOyoCAGixy Pg!/?ss=1102&navtype=BROWSEBYSUBJECT&cid= STELPRDB5259971&navid=190000000000000&pnavid=null&position=News&ttype=detail&pname= Region%202-%20News%20&%20Events. Accessed July 6, 2011.
  23. Leatherman, D.A., et al. 2009. 2008 report on the health of Colorado's forests: Special issue high elevation forests. Fort Collins, CO: Colorado State Forest Service. Online at http://csfs.colostate.edu/pdfs/894651_08FrstHlth_www.pdf. Accessed December 21, 2011.
  24. Safranyik, L., et al. 2010. Potential for range expansion of mountain pine beetle into the boreal forest of North America. Canadian Entomologist 142(5):415–442, doi:10.4039/n08-CPA01. Online at http://www.bioone.org/doi/abs/10.4039/n08-CPA01. Accessed July 6, 2011.
  25. Carlson, M., et al. 2009. Tree breeding overview: Lodgepole pine, western white pine (interior), ponderosa pine, broadleaves (interior). Victoria, BC: Ministry of Forest Mines and Lands. Online at http://www.for.gov.bc.ca/hre/forgen/interior/pine.htm#1. Accessed June 30, 2011.
  26. Carbon Dioxide Information Analysis Center. 2011. Fossil–fuel CO2 emissions: Preliminary 2009 global & national estimates. Oak Ridge, TN: Oak Ridge National Laboratory. Online at http://cdiac.ornl.gov/trends/emis/meth_reg.html. Accessed June 30, 2011.
Climate Hot Spots
 
Africa
 
Asia
 
Australia & New Zealand
 
Europe
 
Latin America
 
North America
 
Polar Regions
 
Small Islands
 
Key to top impacts color code