Potential Consequences of Global Climate Change for the Great Lakes Region Presentation to the Water Quality Board International Joint Commission Joel D. Scheraga National Program Director Global Change Research Program U.S. EPA February 6, 2002
Overview • EPA’s Great Lakes Regional Assessment • The climate is already changing • What the future may hold • Potential consequences for the Great Lakes region • Thinking about adaptation: Some thoughts on follow-up activities (John Furlow)
Great Lakes Regional Assessment • Preparing for a Changing Climate: the Potential Consequences of Climate Variability and Change, • Assessment Team: 30 investigators located throughout Great Lakes region • Focus: • levels of the Great Lakes • stream flow • aquatic and terrestrial ecosystems • agriculture • quality of life.
Observed Changes in the Great Lakes Region • Warmer conditions • More Rainfall Occurring in Intense Downpours • Less snowfall • Reduced Lake Levels • Early Spring (blooms) • Longer Growing Conditions
Temperature Trends: 1901 to 1998 Red circles reflect warming; Blue circles reflect cooling All Stations/Trends displayed regardless of statistical significance. Source: National Climatic Data Center/NESDIS/NOAA
Precipitation Trends: 1901 to 1998 Green circles reflect increasing precipitation; Brown circles reflect decreasing precipitation All Stations/Trends displayed regardless of statistical significance. Source: National Climatic Data Center/NESDIS/NOAA
Trends of Annual Precipitation Intensity 1910-1994 0% +2% +3% +3% 0% +2% 0% +1% +3% More than 2” per day
Observed Climate Trends: 20th Century • Temperature: • Northern portion of Midwest, including Great Lakes, has warmed by almost 4oF • Southern portion, along Ohio River valley, has cooled about 1oF • Precipitation: • Annual precipitation has increased as much as 10-20% • Increased rise in number of days with very heavy precipitation events
Historic Lake Michigan-Huron Water Levels Record highs were set in 1973 and 1986 Over the last year (to March 2000) Lake levels have experienced the second largest decline in about 100 years The lake levels for the past 30 years have been in an extremely high water level regime – the highest in recorded history, due to increased summer and fall precipitation. The lake levels are currently near their longer term (1900-1969) mean.
Expected Climate Change • Temperature: • accelerated warming trend in 21st century • temperatures increasing by 5 to 10oF (3 to 6oC) • Average minimum temperature is likely to increase as much as 1 to 2oF (0.5 to 1oC) more than the maximum temperature • The Canadian Model is warmer and drier than the Hadley Model • Precipitation: • likely to continue its upward trend, at a slightly accelerated rate • 10 to 30% increases are projected across much of the region
Great Lakes Water Resources • Total range of 11 models’ projections for changes in lake levels: • less than a 1 foot increase to more than a 5 foot decrease • Implications: • 5 foot reduction would lead to a 20-40% reduction in outflow to St. Lawrence Seaway • Reductions in hydropower generation downstream of up to 15% by 2050 • Increased costs of navigation of 5 to 40% • Reduced shoreline damage due to high lake levels ranging from 40-80%
Effects of Climate Change on Heavy Lake-Effect Snowstorms near Lake Erie and other Great Lakes Potential Benefits: Such changes in snowstorm frequency would decrease the cost of snow removal and decrease the frequency of transportation disruptions. Potential Disadvantages: Winter recreational industry in southern portions of the Great Lakes would have adverse consequences. For example, business at Midwestern ski resorts was down 50% and losses were estimated at $120 million, during the 1997-1998 El Niño year.
Great Lakes Water Resources: Ice Cover • Likely to decrease • Days with ice cover will decline • Thickness of ice will decline
Potential Climate Change Impacts Health Impacts Weather-related Mortality Infectious Diseases Air Quality-Respiratory Illnesses Agriculture Impacts Crop yields Irrigation demands Climate Changes Forest Impacts Change in forest composition Shift geographic range of forests Forest Health and Productivity Temperature Precipitation Water Resource Impacts Changes in water supply Water quality Increased competition for water Sea Level Rise Impacts on Coastal Areas Erosion of beaches Inundate coastal lands Costs to defend coastal communities Species and Natural Areas Shift in ecological zones Loss of habitat and species
Human Health • Water quality (e.g., drinking water) • Water-borne diseases • Impacts from extreme events • Heat stress • Air quality
Waterborne Diseases • Rainfall and runoff are related to site-specific waterborne disease outbreaks • 51% of waterborne disease outbreaks were preceded by extreme precipitation events • Outbreaks due to surface water contamination showed the strongest association • Association between rainfall and disease is important for water managers, public health officials, and risks assessors Source: Curriero et al. (2001)
Rivers in the Great Lakes Region Will Also be Affected • Stream & river flow into the lakes will likely change. • Inland rivers that are primarily snowmelt driven may have earlier peaks • as a result of less snow and more rain. • Changes in summer flows will depend on how increased precipitation is • balanced by evapotranspiration within watersheds.
Water Ecology • Warmer water likely to create environment more susceptible to invasions by non-native species • Runoff of excess nutrients into lakes and rivers is likely • coupled with warmer temperatures, likely to stimulate growth of algae • will deplete the water of oxygen to the detriment of other living things • Declining lake levels are likely to cause large impacts to distribution of wetlands
Quality of Life • Likely shift in recreational activities • Cold-season recreation will be reduced • skiing • Snowmobiling • ice skating • ice fishing • Warm-season recreation will increase • swimming • hiking • golf • Warm-season recreation likely to be affected by excessive heat
Impacts in Climate Change on Fruit Production in the Great Lakes Region: 2025-2034 Lake-modified regions surrounding Lake Michigan will experience: • moderate increase in growing season length • decrease in the frequency of subfreezing temperatures • important growth stages for perennials (e.g., commercial fruit trees) will occur earlier
Agriculture: Extreme Weather Events • Droughts and floods can result in large yield reductions • Example: Weather conditions during growing season are primary factor in corn and soybean yields • Severe droughts cause yield reductions of over 30% • Example: Drought of 1988
Loss of Habitat for Brown Trout from a Doubling of CO2 - 2050 Not included in analysis * 1-49% Loss 50-100% Loss * Dual screening criteria used for inclusion: 1) Thermal modeling predicts suitability and 2) Fish presence in 10% or more of State’s water bodies. GFDL Climate Change Scenario Source: EPA, 1995
EPA Assessments Already Informing Stakeholder Decisions About Adaptation The Great Lakes Regional Assessment team has hosted workshops to evaluate how assessment findings can inform decision processes. • Great Lakes Water Levels (March 2001) - Loss of a foot of carrying capacity on a 1000 foot vessel leaves 3240 tons behind @ 50 trips per year results in revenue loss for 162,000 tons • Fisheries & Aquatic Ecosystems (June 2001) • Forests and Terrestrial Ecosystems (TBA) • Winter Recreation (TBA) • Agricultural Productivity (TBA)
Contact Information Dr. Joel D. Scheraga National Program Director Phone: (202) 564-3385 Email: Scheraga.Joel@epa.gov Mr. John Furlow Phone: (202) 564-3388 Email: Furlow.John@epa.gov