How could climate change and our response to it affect the Great Lakes' water quality? That's the primary question a team of 27 researchers from across the University of Michigan and collaborators at other institutions will answer with a new $5-million grant from the National Science Foundation.
The researchers will focus on extreme weather events caused by climate change.
The Great Lakes hold 84 percent of North America's surface fresh water, and their basin is home to 10 percent of the U.S. population.
"The suspicion is that climate change will have negative impacts on water quality," said Anna Michalak, principal investigator. "Climate change is expected to bring about more extreme precipitation events, which will cause pulses of water and whatever it's bringing with it, including nutrients, pesticides and sediment. It's these episodic events that can have a significant impact on the water quality."
Michalak is an associate professor in the departments of Civil and Environmental Engineering; and Atmospheric, Oceanic and Space Sciences. Researchers from these departments as well as the School of Natural Resources and Environment and the School of Education are also involved. The educational component of the grant involves work with Ypsilanti New Tech High School, as well as collaborations with Michigan Sea Grant and the Investigate the State program, along with other K-12 outreach.
Water quality in the Great Lakes affects every aspect of life in the region, Michalak said.
"The lakes serve as a source of drinking water and water for agricultural irrigation. They are used for recreation such as boating, swimming and fishing. They are also a key component of the regional economy," she said.
In this project, the researchers will first examine current climate, land use, precipitation and water governance patterns. They will combine this data with future climate change models to forecast how warming will affect:
Rain and snowfall frequency and quantity.
Land use and agricultural crop changes.
Phosphorous pollution in the Great Lakes.
As a result of all of the above, Great Lakes water quality.
They will also explore what strategies watershed councils and other government entities could employ to reduce water quality impacts.
While much research exists about how global warming could affect the amount and availability of water, less is known about its effects on water quality, Michalak said.
The broad scope of this project is unique. Researchers will study the intersection of climate, hydrology, ecology and social systems.
Allison Steiner, an assistant professor in the Department of Atmospheric, Oceanic and Space Sciences, leads a group that will explore how climate and land cover changes can influence the regional precipitation cycle. The climate group will look, for example, at how ice cover in the Great Lakes can influence wind and precipitation patterns, and how agricultural changes could influence summer rain, which is affected by soil moisture levels.
Michael Moore, a professor in the School of Natural Resources and Environment, directs a team that will chart population and agricultural crops by county for the entire United States. For the Great Lakes region, they will gather even finer detail. Then they will project how a warming climate could change these patterns.
On a regional scale, land-use changes can have a more significant impact on climate than greenhouse gas emissions, Michalak said. Greenhouse gases have a more global effect.
"Everyone is quite excited about the opportunity for integration and synthesis across disciplines," Moore said. "We're working at the boundaries of atmospheric science, economics and geography of land use. This is a question that can't be answered by a single discipline or a single science in isolation. To be able to answer these questions, we need integration and interdisciplinary work."
Other collaborators on this project are at Heidelberg University, the University of Toledo, Grace College, Michigan Sea Grant's Great Lakes Observing System and the Cooperative Institute for Limnology and Ecosystems Research, which is a joint institute between the National Oceanic and Atmospheric Administration and U-M, and LimnoTech Inc.