Nav: Home

Changes in rainfall and temperatures have already impacted water quality

April 24, 2019

Washington, DC--Changes in temperature and precipitation have already impacted the amount of nitrogen introduced into U.S. waterways, according to new research from a team of three Carnegie ecologists published this week in Environmental Science & Technology.

Nitrogen from agriculture and other human activities washes into waterways, which, in excess, creates a dangerous phenomenon called eutrophication. This can lead to toxin-producing algal blooms or low-oxygen dead zones called hypoxia. Over the past several summers, dead zones and algal blooms in lake and coastal regions across the United States have received extensive news coverage.

Carnegie's Anna Michalak and her team have spent several years studying the effects of nitrogen runoff and how expected changes in precipitation patterns due to climate change could lead to greater risks to water quality.

But their efforts so far have focused on making predictions of the future. Now, with Tristan Ballard, they looked backward to analyze long-term trends in nitrogen runoff going back to the 1980s.

"We wanted to see whether we could find evidence in the historical record of changes in temperature and precipitation affecting the amount of nitrogen that gets into watersheds in the contiguous U.S.," said lead author Ballard. "Our findings could improve our modeling of future risks and guide management efforts."

They found that climate was a key factor in how much nitrogen ended up in the water system, with warming springtime temperatures and accompanying storms having a direct impact on nitrogen runoff.

Agriculture played a role, too, but it was more complicated than a simple one-and-one correlation.

For example, in the northern Great Plains, increased farming and climate conditions compounded to put more nitrogen in the waterways. However, in the Great Lakes, despite efforts to reduce the amount of nitrogen released by human activity, precipitation increased so much that nitrogen still overloaded the water system.

"What we have shown is that deteriorating lake and coastal water quality is not just about how we develop land and how much fertilizer we use on fields; it's also about how human action at a global scale is changing rainfall and temperatures," Michalak said. "It's a complex system, but it comes down to better managing human impacts across scales, from your own backyard to the planet as a whole."

The team says their findings mean that management strategies will become even more challenging over time. Simply decreasing the amount of nitrogen released by industry and farming will not be enough. The decreased usage will have to be enough to offset greater risk due to increased precipitation, too.
-end-
The Carnegie Institution for Science (carnegiescience.edu) is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

Carnegie Institution for Science

Related Climate Change Articles:

A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
Historical climate important for soil responses to future climate change
Researchers at Lund University in Sweden, in collaboration with colleagues from the University of Amsterdam, examined how 18 years of drought affect the billions of vital bacteria that are hidden in the soil beneath our feet.
Can forests save us from climate change?
Additional climate benefits through sustainable forest management will be modest and local rather than global.
From crystals to climate: 'Gold standard' timeline links flood basalts to climate change
Princeton geologists used tiny zircon crystals found in volcanic ash to rewrite the timeline for the eruptions of the Columbia River flood basalts, a series of massive lava flows that coincided with an ancient global warming period 16 million years ago.
Think pink for a better view of climate change
A new study says pink noise may be the key to separating out natural climate variability from climate change that is influenced by human activity.
More Climate Change News and Climate Change Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Accessing Better Health
Essential health care is a right, not a privilege ... or is it? This hour, TED speakers explore how we can give everyone access to a healthier way of life, despite who you are or where you live. Guests include physician Raj Panjabi, former NYC health commissioner Mary Bassett, researcher Michael Hendryx, and neuroscientist Rachel Wurzman.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab