Understanding A Warming World

While most Americans are becoming increasingly aware of the seriousness of climate change, you might like to know that many URI researchers have been studying the topic for decades and from a wide variety of perspectives.

Just this summer, for example, Oceanography Professor Jeremy Collie and Professor Emeritus Perry Jeffries received national attention for their report on the significant changes that have taken place in the fish community in Narragansett Bay from increasing water temperatures.

By analyzing nearly 50 years of data from the University’s weekly fish trawl surveys, they found that while warm-water species have moved into the region in larger numbers, cool-water species—primarily bottom feeders like winter flounder—have declined. Invertebrates like lobsters and crabs have increased, but the maximum size of fish has declined. All results are linked to global warming.

“Our overall prediction is that Narragansett Bay is soon going to resemble estuaries to the south of us—Delaware Bay, Chesapeake Bay—so we’ll experience what they are experiencing now,” Collie said. “Narragansett Bay will continue to get warmer and attract more southern species, such as blue crabs. Species that couldn’t complete their life cycle here before may be able to do that now.”

Oceanography Professor S. Bradley Moran is conducting a somewhat similar analysis half way around the world. Along with Associate Marine Research Scientist Robert Campbell, he is examining shifts in the productivity, abundance, and species composition of ice algae, phytoplankton and zooplankton in open water areas of the Bering Sea and in areas where the ice cover is receding due to warming temperatures. According to the researchers, warmer water temperatures in the Bering Sea in spring could result in an earlier and more rapid seasonal ice retreat with potentially harmful effects on one of the world’s richest and most productive fisheries.

“The Bering Sea and other sub-Arctic and Arctic seas are predicted to be among the regions most severely affected by global warming, as relatively small changes in the heat content of the water column can have a disproportionately large effect on the spatial distribution and dynamics of sea ice,” Moran said. “This research will improve our understanding of climate-driven ecological changes that have occurred over the past decade.”

When not studying squid and other marine organisms living in extreme environments, Brad Seibel focuses his research on the effects of fossil fuel emissions on marine life. While there is a natural exchange of carbon dioxide from the atmosphere to the sea and back, he notes that increasing CO2 levels from power plants, transportation, and other man-made sources are affecting the equilibrium.

Seibel, associate professor of biological sciences, said that increased CO2 in the oceans causes a decrease in the pH levels (the measure of acidity) of seawater, resulting in dramatic physiological effects on many species. As atmospheric CO2 diffuses into the upper layers of the water, it inhibits the ability of shellfish to form shells and causes coral reefs to dissolve. Metabolism in some animal species may also be depressed by increased acidity, and some fish, squids, and shrimps will have a diminished capacity for oxygen uptake from their gills to their bloodstream, leading to asphyxiation.

Still other faculty members are examining global warming from a larger perspective. Oceanography Professor Randy Watts and Associate Research Professor Kathleen Donohue, for instance, make annual visits to the waters around Antarctica to study changes in ocean circulation patterns in one of the world’s most important regions for heat exchange.

According to Donohue, the Southern Ocean is warming faster than other oceans, and winds in the region have increased significantly in the last 30 years, so it is a key location to look for the impacts of climate change. “The Antarctic Circumpolar Current acts as a conduit transporting water between the Atlantic, Pacific, and Indian Oceans. The nature of this interaction has consequences for local, regional and global ecosystems and climate,” she said. “It’s important to understand the dynamics of the current so we can understand the impacts of our changing climate.”

For many years, Oceanography Professor John Merrill has been monitoring greenhouses gases in the atmosphere, especially ozone, and in 2007 he was honored with the Outstanding Scientific Paper award in the climate category from the research arm of the National Oceanic and Atmospheric Administration. He and a team of colleagues found a previously unknown atmospheric feature—an area hundreds of kilometers in size above the southeastern United States where a surprisingly large amount of ozone has been present in recent summers.

Examining Historical Changes

Another way to understand the climate changes taking place is to examine similar changes in Earth’s history. Kate Moran, associate dean of the Graduate School of Oceanography, and Oceanography Professor John King are doing just that. Moran led an international team of scientists to collect a 400-meter sediment core from beneath the Arctic Ocean that revealed a 56-million-year record of climate changes in the region.

“Little direct evidence about the environmental history of the Arctic Ocean existed before our cruise, partly because of the enormous technological challenges of collecting the samples,” Moran said. “Our analysis of the core sample suggests that 55 million years ago the Arctic was much warmer than today. We anticipate that our data will be used by climate modelers to give us better information about how climate change occurs and possibly where global climate might be heading.“

Similarly, King is collecting sediment cores from lakes in Africa and the eastern United States and from estuaries in Rhode Island to analyze the history of climate changes in those areas. By studying the annual sediment layers—somewhat like examining tree rings—he can determine precipitation rates and other climactic conditions from tens of thousands of years ago. Using this technique, he and colleagues from the U.S. and Canada recently discovered that water levels in the eastern Great Lakes dropped by 35 meters due to a significant climate change 7,800 to 8,800 years ago.

“This study proves again that large ecosystems like the Great Lakes are much more sensitive to major natural climate changes than we previously believed, and this discovery doesn’t bode well for the Great Lakes during the major human-induced climate change that is unfolding now,” King said. “We tend to assume that large natural systems can take whatever we can dish out, but unfortunately the detrimental societal impacts for the U.S. and Canada of a large drop in lake levels may prove to be staggering.”

Seeking Solutions

As temperatures continue to rise, a number of University scientists, all participants in the URI Partnership for Energy, are focusing on how to reduce the impact.

For example, Molecular Biology Professor Albert Kausch is developing an improved switchgrass plant that can be used as an effective and inexpensive alternative to corn for ethanol; Chemical Engineering Professor Stanley Barnett is working to convert CO2 for use as a replacement for oil; and Chemistry Professor Brett Lucht is investigating methods to enhance the life of lithium ion batteries for the next generation of hybrid vehicles. Lucht and Marion Gold, co-directors of the energy partnership, recently completed a report for the Rhode Island Energy Efficiency and Resource Management Council that assesses the potential use of small-scale renewable energy systems at homes and businesses in the state and recommends policies that could be implemented to encourage their use.

“If we’re going to make any meaningful impact on reducing the predicted global temperature increases, we need to start with our energy use,” said Gold. “That means we have to quickly find alternatives to fossil fuels for powering our vehicles, generating electricity, and heating and cooling our homes. And we have to find ways to make it easy for citizens to purchase and use these alternatives as well as to become more efficient energy consumers.”

From a policy perspective, Fred Meyerson said that the key to reducing climate change is reducing per-capita emissions of greenhouse gases and reducing population growth. During an online round-table debate on the subject, the assistant professor of demography, ecology, and environmental policy said: “The only viable way to lower per-capita emissions is to make the price of emitting greenhouse gases so high that it’s in everyone’s best interest to reduce consumption and turn to other technologies for producing energy, goods, and services. This will involve significant economic and social change and disruption, but then so did the industrial and fossil-fuel revolutions of the past 200 years that fostered the population growth that brought us to this demographic and climate crisis.”

By Todd McLeish