Expected impacts of climate change in the Great Lakes region
Air temperature is expected to increase by 3-11 degrees C by 2100.
Warmer temperatures may cause seasonal events to occur earlier. The timing of these events may not correspond as they do under current conditions.
- Plant leaf-out and flowering
- Bird migration and nesting
- Insect emergence
- Timing of last spring frost (earlier) and first fall frost (later), extending the growing season.
Surface water temperatures are projected to increase 0.37-0.93°C per decade in Lake Superior to 0.20-0.60°C per decade in Lake Erie by 2100.1
Water temperature changes may:
- Affect the metabolism of ectothermic organisms, especially fish.
- Alter the ranges and abundances of many species due to changes in thermal habitat. Some species, especially those at the southern edges of their ranges, could be lost.
- Affect the timing of seasonal events such as spring blooms of algae.
- Promote the spread of nuisance algae and invasive species.
- Lead to more and larger areas of hypoxia.
Climate change will decrease the duration and extent of winter ice cover.
- Ice will form later in the fall and melt earlier in the spring.
- In combination with increased air and water temperatures, a decrease in ice cover will increase evaporation rates in the Lakes, leading to a potential drop in water level.
- The reproductive success of winter spawning fish (e.g., whitefish) that require ice cover to protect developing eggs, may decline in some areas.
Climate models predict up to a 20% increase in precipitation by 2100, with higher precipitation occurring during the winter and spring and decreased overall precipitation, but more extreme storm events occurring in the summer.2,3
Higher winter and spring precipitation is expected to cause:
- Increased agricultural and urban stormwater run-off.
- Increased spring flooding, leading to property damage and greater stress on infrastructure.
More variable summer precipitation has the potential to cause:
- More frequent periods of drought.
- Greater stress on groundwater supplies, as more water is required for irrigation.
- More combined sewer overflows (CSOs) and more urban run-off from intense summer storms, leading to declines in water quality and increased beach contamination.
Water levels are expected to change due to the combined effects of warmer temperatures and less ice cover, though the magnitudes of predicted decreases are uncertain.
Lower water levels may:
- Eliminate connections to coastal wetlands that provide critical habitat to numerous Great Lakes fish species.
- Expose areas with contaminated sediments in some locations.
- Reduce cargo capacity for the shipping industry.
- Affect recreational boating.
- Affect industries drawing water from the Lakes (e.g., power generation, drinking water, manufacturing).
For more information
Check out these excellent resources on climate change in the Great Lakes region
Great Lakes Integrated Science + Assessment (GLISA): GLISA is comprised of an interdisciplinary group of researchers and specialists in stakeholder outreach from the University of Michigan, Michigan State University, Ohio State University, and Michigan Sea Grant who work to on climate issues specific to the Great Lakes region.
Healing Our Waters-Great Lakes Coalition (HOW): HOW consists more than 115 environmental, conservation, and outdoor recreation organizations, zoos, aquariums and museums and works to advance Great Lakes restoration and promote restoration funding. A 2008 report, Great Lakes Restoration and the Threat of Global Warming (pdf), describes potential impacts of climate change in the Great Lakes region.
International Association of Great Lakes Research (IAGLR): IAGLR is a scientific organization made up of researchers studying the Laurentian Great Lakes, other large lakes of the world, and their watersheds, as well as those with an interest in such research. A group of researchers prepared the report, The Great Lakes at a Crossroads: Preparing for Climate Change (pdf, 2009).
Michigan Sea Grant: Michigan Sea Grant provides a series of fact sheets about Great Lakes climate change on its website.
NOAA-Great Lakes Environmental Research Lab (GLERL): Scientists at NOAA-GLERL are involved in cutting edge research on climate change and its impact on Great Lakes ecosystems.
U.S. Environmental Protection Agency (USEPA): The USEPA has excellent general information on climate change.