Potential Consequences of Global Climate Change for the Great Lakes Region - PowerPoint PPT Presentation

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

• 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

0%

+2%

+3%

+3%

0%

+2%

0%

+1%

+3%

More than 2”

per day

• 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.

What the Future May Hold

• 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

• 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.

• 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

• Water quality (e.g., drinking water)
• Water-borne diseases
• Impacts from extreme events
• Heat stress
• Air quality

• 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.

• 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

• 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

• 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

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)

www.epa.gov/globalresearch

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