Global Warming Effects Around the World

Prairie Pothole Region, South Dakota, USA

Top Impact

Ecosystems (Lakes and rivers)

Other Impacts

Temperature (Air)

People (Costs)

Prairie pothole wetland region in peril from rising temperatures.

The Prairie Pothole Region of north–central United States and the central plains of Canada is the breeding ground for 50 to 80 percent of waterfowl in North America. A hotter climate threatens to dry out this region's extensive wetlands.1

Key Facts

The Prairie Pothole Region (PPR), which encompasses 5 to 8 million small wetlands, is one of the most ecologically valuable freshwater resources in the United States.2 The region stretches from northwestern Iowa into south–central Canada.3 The wetlands provide abundant ecosystem services, including flood control, groundwater recharge, water for agriculture, water purification, and recreation.2

  • The Prairie Pothole Region is considered the world's most productive habitat for waterfowl,4 and is the breeding ground for 50 to 80 percent of waterfowl in North America.7
  • Warming temperatures threaten the entire region.5 Wetlands dry up more quickly in hotter weather, unless there is an accompanying increase in precipitation.
  • The western part of the PPR in the United States became drier during the twentieth century, while the eastern part became wetter.5
  • Despite more favorable conditions in eastern sections of the PPR, many have been drained and developed for agriculture. This undercuts their potential to compensate for habitat losses in western sections stemming from a drier, hotter climate.4

Details

The Prairie Pothole Region of the Northern Great Plains includes parts of Iowa, Minnesota, South Dakota, North Dakota, and Montana, as well as sections of Manitoba, Saskatchewan, and Alberta.3 The PPR consists of extensive natural grasslands interspersed with millions of shallow temporary, seasonal, and permanent wetlands and river systems. 6 This rich ecosystem is considered the world's most productive habitat for waterfowl, and is the breeding ground for 50 to 80 percent of waterfowl in North America.7,4

However, many of the wetlands—particularly those in Iowa, Minnesota, and the eastern Dakotas—have been drained and developed for agriculture.3 Estimates range from more than half of the wetlands lost in the Dakotas to more than 99 percent lost in Iowa.6 Canada also lost 40 percent or more of its prairie wetlands to drainage in the twentieth century.8

Although attention has focused on saving this wetlands ecosystem for waterfowl, the PPR helps the region in a wide variety of ways. Prairie wetlands reduce flooding by capturing large amounts of water during heavy rains or snowmelt, allowing the water to recharge groundwater instead of flowing away as runoff. This groundwater is then available for drinking and irrigation in drier times.3 The Prairie Pothole Region is also effective at sequestering or storing, carbon: uncultivated grassland soil stores up to 26 percent more carbon than cultivated soil. 9

Finally, people use the region extensively for recreation, from camping and wildlife viewing to fishing and hunting. These recreational activities spur a significant amount of spending in the region on items such as lodging and equipment rentals. For example, migratory bird hunters in the Dakotas, Iowa, and Minnesota shell out more than $100 million each year on hunting–related purchases.10,11,12,13

Because the PPR encompasses such a wide area, temperatures vary from north to south. However, the average temperature in the U.S. section rose during the twentieth century, with higher–latitude locations generally warming faster than lower–latitude regions.14 For example, in South Dakota, the average temperature was almost 2° F (1.1° C) higher from 2001 to 2010 than from 1895 to 1905. 15 In North Dakota, the average temperature was almost 3.6° F (2° C) higher from 2001 to 2010.16

Temperatures have also been rising in the Canadian sections of the PPR. Researchers observed significant increases in average air temperatures from 1961 to 2003.17 Minimum temperatures rose at a slightly faster rate than maximum temperatures, while winter temperatures increased at more than twice the annual rate.17

Precipitation levels vary sharply across the region, with western sections drier and eastern sections wetter. For example, the PPR in southwestern Minnesota recorded almost twice as much rain as the PPR in northeastern Montana during the decade at the turn of the nineteenth and twentieth century.18,19 This difference widened during the twentieth century. While southwestern Minnesota received almost 20 percent more precipitation at the end of the twentieth century than at the start, northeastern Montana received about 10 percent less.18,19

What the Future Holds

Prairie potholes—geologic indentations left behind by glaciers—are particularly vulnerable to climate change because they cannot escape environmental stressors.20,3 As temperatures rise, evaporation of the water in the wetlands occurs more quickly. Unless an increase in temperature is accompanied by enough of an increase in precipitation, the region gets drier.

Waterfowl depend on the PPR's semi–permanent wetlands for breeding. This type of wetland allows enough time for ducklings to mature so they can fly to find water when the wetland dries out later in the year. A study of mallard ducklings in North Dakota found that their survival rate when fewer seasonal wetlands were available during drought was less than one–seventh the rate when water was abundant.21 If spring arrives earlier and summers are hotter, wetlands may dry up too quickly and become a trap for migrating ducks raising their young.22

In one study, scientists found that temporary and seasonal wetlands remained wet for a much shorter time unless accompanied by an increase in precipitation of 2.7 to 3.8 percent per degree F (5 to 7 percent per degree C) of warming.22 Another study found that when precipitation declined or even held steady at historic levels, conditions in the PPR became critically dry.4

During the twenty–first century, average summer temperatures in the region could rise by 6° F (3.3° C), or more than 10° F (5.6° C), depending on the amount of heat–trapping emissions we release into the atmosphere.23 Given historical trends, scientists expect larger temperature increases in the northern portion of the region.23

Precipitation levels are projected to increase 10 to 30 percent, particularly in winter and spring, depending on the amount of heat–trapping gases in the Earth's atmosphere.5 However, an intensified hydrologic cycle will mean that both drought and deluge occur more often.20,24 Summers, especially, may be drier across much of the Midwest.24

Temperature increases of more than 10° F (5.6° C) without an increase in precipitation of 27 to 38 percent would mean that the Prairie Pothole Region would become drier, leaving much less habitat suitable for waterfowl to breed and thrive.23,4 And projections of precipitation changes are more uncertain than the amount of warming that will occur from different levels of carbon overloading in the atmosphere.25

The choices we make today can help determine what our climate will be like. Significantly reducing our heat–trapping emissions and developing cleaner energy technologies would help us slow the pace of climate change while improving our air quality and public health. Such efforts would also give us more time to protect communities from the potential impact of higher temperatures, at lower cost.

Credits

Endnotes

  1. Photograph courtesy of U.S. Fish and Wildlife Service. Online at: http://www.fws.gov/WAUBAY/landscape_photos.html. Accessed 03/09/12.
  2. U.S. Geological Survey. 2006. Patuxent Wildlife Research Center: Prairie wetlands and climate change—Droughts and ducks on the prairies. Reston, VA: Department of the Interior. Online at http://www.pwrc.usgs.gov/products/factshts.cfm. Accessed July 27, 2011.
  3. B.V. Millett et al. 2009. Climate trends of the North American Prairie Pothole Region, 1906–2000. Climatic Change 93:243–267. Online at http://files.dnr.state.mn.us/publications/volunteer/online_extras/sepoct09/climate_trends.pdf. Accessed September 6, 2011.
  4. W.C. Johnson et al. 2005. Vulnerability of northern prairie wetlands to climate change. BioScience 55(10):863–872; doi:10.1641/0006-3568(2005)055[0863:VONPWT]2.0.CO;2. Online at http://www.bioone.org/doi/abs/10.1641/0006-3568%282005%29055%5B0863:VONPWT%5D2.0.CO%3B2. Accessed July 27, 2011.
  5. U.S. Global Change Research Program. 2009. Global climate change impacts in the United States, edited by T.R. Karl, J.M. Melillo, and T.C. Peterson. New York, NY: Cambridge University Press. Online at http://library.globalchange.gov/products/assessments/2009-national-climate-assessment. Accessed July 31, 2011.
  6. R.W. Tiner et al. 2002. Geographically isolated wetlands: A preliminary assessment of their characteristics and status in selected sreas of the United States. Hadley, MA: U.S. Fish and Wildlife Service, Northeast Region. Online at http://www.csu.edu/cerc/researchreports/documents/GeographicallyIsolatedWetlands2002.pdf. Accessed September 6, 2011.
  7. R. Loehman. 2009. Understanding the science of climate change: Talking points—Impacts to prairie potholes and grasslands. Natural Resource Report NPS/NRPC/NRR–2009/138. Fort Collins, CO: National Park Service. Online at http://www.nature.nps.gov/climatechange/docs/PrairieGrasslandsTP.pdf. Accessed July 31, 2011.
  8. Environment Canada, Canadian Wildlife Service, and U.S. Fish and Wildlife Service. 1986. 1986 North American waterfowl management plan. Cited in B.G. Cortusm et al. 2011.The economics of wetland drainage and retention in Saskatchewan. Canadian Journal of Agricultural Economics/Revue Canadienne D'Agroeconomie 59(1):109–126; doi:10.1111/j.1744–7976.2010.01193.x. Online at http://onlinelibrary.wiley.com/doi/10.1111/j.1744-7976.2010.01193.x/abstract. Accessed September 3, 2011.
  9. R.A. Gleason, K. Murray, K. Laubhan, and N.H. Euliss. eds. 2008. Ecosystem services derived from wetland conservation practices in the United States prairie pothole region with an emphasis on the U.S. Department of Agriculture conservation reserve and wetlands reserve programs. Professional paper 1745. Reston, VA: U.S. Geological Survey. Online at http://pubs.usgs.gov/pp/1745/. Accessed July 31, 2011.
  10. U.S. Fish and Wildlife Service and U.S. Census Bureau. 2006. National survey of fishing, hunting, and wildlife–associated recreation: Iowa. Washington, DC. Online at http://www.census.gov/prod/www/abs/fishing.html. Accessed July 28, 2011.
  11. U.S. Fish and Wildlife Service and U.S. Census Bureau. 2006 National survey of fishing, hunting, and wildlife–associated recreation: Minnesota. Washington, DC. Online at http://www.census.gov/prod/www/abs/fishing.html. Accessed July 28, 2011.
  12. U.S. Fish and Wildlife Service and U.S. Census Bureau. 2006. National survey of fishing, hunting, and wildlife–associated recreation: North Dakota. Washington, DC. Online at http://www.census.gov/prod/www/abs/fishing.html. Accessed July 28, 2011.
  13. U.S. Fish and Wildlife Service and U.S. Census Bureau. 2006. National survey of fishing, hunting, and wildlife–associated recreation: South Dakota. Washington, DC. Online at http://www.census.gov/prod/www/abs/fishing.html. Accessed July 28, 2011.
  14. National Oceanic and Atmospheric Administration, National Climatic Data Center. U.S. statewide analysis: Climate at a glance annual temperature 1900–2010 trend for Minnesota, Montana, North Dakota, and South Dakota. Asheville, NC. Online at http://www.ncdc.noaa.gov/oa/climate/research/cag3/state.html. Accessed September 6, 2011.
  15. National Oceanic and Atmospheric Administration, National Climatic Data Center. 2011. U.S. statewide analysis: Climate at a glance annual temperature–South Dakota. Asheville, NC. Online at http://www.ncdc.noaa.gov/oa/climate/research/cag3/state.html. Accessed July 31, 2011.
  16. National Oceanic and Atmospheric Administration, National Climatic Data Center. 2011. U.S. statewide analysis: Climate at a glance annual temperature–North Dakota. Asheville, NC. Online at http://www.ncdc.noaa.gov/oa/climate/research/cag3/state.html. Accessed July 31, 2011.
  17. Y.B. Dibike, T. Prowse, R. Shrestha, and R. Ahmed. 2011. Observed trends and future projections of precipitation and air temperature in the Lake Winnipeg watershed. Journal of Great Lakes Research 38(1):1–186; doi:10.1016/j.jglr.2011.04.005. Online at http://www.sciencedirect.com/science/article/pii/S0380133011000748. Accessed September 3, 2011.
  18. National Oceanic and Atmospheric Administration, National Climatic Data Center. 2011. Minnesota precipitation plot time series, 12–month accumulation as of December, January–December 1895–2010. Asheville, NC. Online at http://www.ncdc.noaa.gov/temp-and-precip/time-series/. Accessed July 27, 2011.
  19. National Oceanic and Atmospheric Administration, National Climatic Data Center. 2011. Montana precipitation plot time series, 12–month accumulation as of December, January-December 1895–2010. Online at http://www.ncdc.noaa.gov/temp-and-precip/time-series/. Accessed July 27, 2011.
  20. D.S. Ojima, J.M. Lackett, and the Central Great Plains Steering Committee and Assessment Team. 2002. Preparing for a changing climate: the potential consequences of climate variability and change: Central Great Plains. A report for the U.S. Global Change Research Program. Fort Collins, CO: Colorado State University. Online at http://www.nrel.colostate.edu/projects/gpa/gpa_report.pdf. Accessed July 27, 2011.
  21. G.L. Krapu et al. 2006. Mallard brood movements, wetland use, and duckling survival during and following a prairie drought. Journal of Wildlife Management 70:1436–1444. Cited in: W.C. Johnson et al. 2010. Prairie wetland complexes as landscape functional units in a changing climate. BioScience 60(2):128–140; doi:10.1525/bio.2010.60.2.7. Online at http://www.bioone.org/doi/abs/10.1525/bio.2010.60.2.7. Accessed July 27, 2011.
  22. W.C. Johnson et al. 2010. Prairie wetland complexes as landscape functional units in a changing climate. BioScience 60(2):128-140; doi:10.1525/bio.2010.60.2.7. Online at http://www.bioone.org/doi/abs/10.1525/bio.2010.60.2.7. Accessed July 27, 2011.
  23. CMIP3-B. As cited in U.S. Global Change Research Program. 2009. Global climate change impacts in the United States, edited by T.R. Karl, J.M. Melillo, and T.C. Peterson. New York, NY: Cambridge University Press. Online at http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/download-the-report. Accessed July 31, 2011.
  24. America's Climate Choices: Panel on Advancing the Science of Climate Change; National Research Council. 2010. Advancing the science of climate change. The National Academies Press. Online at http://www.nap.edu/catalog.php?record_id=12782. Accessed July 31, 2011.
  25. E. Hawkins and R. Sutton. 2011. The potential to narrow uncertainty in projections of regional precipitation change. Climate Dynamics 37(1,2):407–418; doi:10.1007/s00382-010-0810-6. Online at http://www.springerlink.com/content/g3m4q2613571094j/.
Climate Hot Spots
 
Africa
 
Asia
 
Australia & New Zealand
 
Europe
 
Latin America
 
North America
 
Polar Regions
 
Small Islands
 
Key to top impacts color code