The Water Cycle Revisited: What’s it Got to Do with Climate Change?
By Nancy Stoner
When you think of climate change, you probably think of greenhouse gases and the odd behavior of the weather lately. But when I think of climate change, I worry about what it means for our nation’s wetlands, estuaries and fisheries, as well as water infrastructure.
Climate change is already altering many patterns of precipitation in the U.S., including when, where, how much, and what kind of precipitation falls. There is more evaporation, drying soils and lower lake and stream volumes – and people end up using more water to keep our lawns and trees alive. But more evaporation means there is more water in the atmosphere so when it rains, it pours. Some regions – for example, the arid Southwest — are projected to experience longer and more severe droughts.
So it gets drier in some places, wetter in others and timing changes a little. What’s the big deal? Well, our cities and towns, farms, and environment have all evolved for particular ranges of weather patterns. Folks in the Pacific Northwest rely on slow melting of their snowpack to fill drinking water reservoirs. Too much melting too fast cannot be accommodated with current storage infrastructure and may alter aquatic habitats. Storm drains on your street are designed to accommodate quantities of rainwater that are ‘typical’ in your area, and overwhelmed storm systems lead to flooding and overflows of sewers. In areas experiencing drought, lack of surface water supplies lead communities to withdraw more from ground water. Cold water fish such as trout or salmon will need to migrate while warm water fish move into formerly cold water habitat.
Water managers are working to figure out how to respond. For our part, the EPA water program has just published for public comment its updated strategy to address climate change. This strategy features our goals and the strategic actions to take in the coming years to be a ‘climate ready’ water program. This includes working to build resilience to climate change for infrastructure, watersheds and wetlands, coastal and ocean waters, and water quality. This strategy also includes a section on working with tribes to address their vulnerability.
It is important for us all to prepare for the unfolding impacts of climate change, including on water. To learn more, please see our new website.
About the author: Nancy Stoner is the Acting Assistant Administrator for the EPA’s Office of Water
Editor's Note: The opinions expressed in Greenversations are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.