A group of U.S. mayors, including St. Paul's Chris Coleman, is focusing its attention on rivers, as world leaders gather in Paris for international climate talks.
Coleman and other members of the Mississippi River Cities and Towns Initiative — which pushes for better water quality along the river — traveled to the U.N. Conference on Climate Change in France to learn how other river communities are addressing the challenges of quality and climate.
"We've had quite an extraordinary week here in Paris," Coleman said. "We've had an amazing opportunity to meet with our colleagues from river basins across the globe."
Many worry that climate change has increased the frequency and severity of two of the biggest natural problems facing rivers: flooding and drought.
Flooding increases pollutants, while drought reduces a stream's ability to meet demands for drinking water and other uses. Coleman said communities along the river need to do their part to limit the impact of weather events, "to understand the impacts of climate change and to understand what we need to do collectively to make sure that we protect our waterways."
That includes limiting carbon emissions to reduce the severity of climate change. Coleman said St. Paul has taken steps in that direction, including an increase in its use of renewable energy.
Several organizations, including the Mississippi River group, an organization representing the Rhine in Europe and the International Network of Basin Organizations, signed an agreement to improve environmental conditions along waterways.
The agreement calls for stabilizing riverbank erosion; reducing urban runoff; and encouraging sustainable agriculture practices like planting cover crops to limit the movement of soil and nutrients into rivers.
Ted Suss, who lives in southwest Minneapolis, has worked for years to improve water quality in one of the state's most polluted streams: the Minnesota River. The river's heavy load of sediment and nutrients like nitrates and phosphorus mostly ends up in the Mississippi.
Suss said the talks in Paris, which he's watched online, reflect what he's found to be true in his Minnesota River efforts: Building a coalition is the best way to improve water quality.
"You need to have all the stakeholders in the basin engaged voluntarily," he said. "And you need to make decisions as much as possible by consensus."
Some farmers are part of that consensus. Most government regulators like the Minnesota Pollution Control Agency have found that agriculture is a major contributor to river pollution.
George Rehm helps manage a project supported by the major agricultural groups known as Discovery Farms Minnesota. He said one goal of the project is to find ways to reduce the runoff of fertilizer. Rehm said the Paris meeting will help advance the effort to improve river quality. But he doesn't expect it to be a quick solution.
"We're not going to get to zero, we're always going to have some nutrients leaving the landscape," Rehm said. "But the amounts are going to be diminished, and they have been diminished."
The increasing impacts of climate change may mean that improvements in farming techniques will need to happen more quickly than in the past.