Scientists discuss climate challenges and solutions during 2021 One Health Day

As climate experts and scientists huddled in Glasgow in an international effort to stem potentially disastrous global environmental changes, a panel of doctors representing multiple disciplines at the University of Tennessee and beyond offered their assessments of climate challenges and solutions.

Their take on climate change? We have problems, but we also have solutions. Hopelessness will drive you crazy. Stay healthy, stay informed and do your part to mitigate the long-term environmental consequences of a changing Earth. 

Above all: Don’t despair and don’t lose hope.

The panel, held Nov. 3 at the UT Student Union and presented by the UT One Health Initiative, consisted of the following experts:

— Dr. Gus Engman, Department of Forestry, Wildlife, and Fisheries, University of Tennessee Institute of Agriculture 

— Dr. Kate Evans, Computational Sciences and Engineering Division, Oak Ridge National Laboratory

— Dr. Joshua Fu, Department of Civil and Environmental Engineering, University of Tennesse

— Dr. Sindhu Jagadamma, Biosystems Engineering and Soil Science, University of Tennessee Institute of Agriculture

— Dr. Kristina Kintziger, Department of Public Health, University of Tennessee

Answers have been edited for clarity and brevity and don’t include the full response. Questions were submitted ahead of time or during the panel discussion. 

What do you see as the largest threats of climate change, especially related to your individual research interests?

Engman: Changing precipitation patterns are something I think about a lot.

Pretty much all the rivers in the world are expected to have changes to their flow regime.

These changes in droughts and floods are a really large issue.

I think a lot about aquatic communities. If we are scarce on drinking water, we are always going to prioritize people having that water, over the fish or the bugs in the streams. 

There are all kinds of impacts to life histories and interactions with communities in streams. 

When animals are stressed because of these changes in precipitation patterns and changes in flow patterns, they might become more susceptible to other stressors, like disease. 

Changes in algal community composition can impact the entire water quality of a stream, and that might happen because of these changes in precipitation patterns.

These places that are experiencing these extreme droughts really worry me. The Colorado River already doesn’t even flow all the way to the ocean anymore. That’s a huge change. Because we take up so much water for agriculture. 

If a stream runs out of water, it’s not a stream anymore.

Evans: From a meteorological perspective, the biggest event that hurts people's health is actually heat waves. A lot of press goes to tornadoes and hurricanes and storms but in fact these large domes of hot air (are deadly), which happen because of changes in the large-scale weather patterns.

The greenhouse effect insulates the earth, it makes it more uniform in temperature and so that changes the flow patterns that go around the earth. That changes those big weather systems that come in and how long they stick around. 

When you talk about these long droughts, we know that’s what's we have to understand: Will they last longer, be more humid, less humid, and that has huge impacts for human health as well as the food they eat and the plants that grow. 

Kintziger: Heat also has a bigger impact on a more indirect pathway to human health. Not just heat-related illness but also cardiovascular impacts, renal impacts and even mental health impacts.

Heat is the one that keeps me up at night. We are seeing increasing temperatures globally and we also have this urban heat island affect. 

Our vulnerable populations in the cities — inner cities with lower-income housing, homeless populations — they are going to experience heat very differently than people who live in newer buildings with better cooling and infrastructure and have better capabilities for adapting to heat. 

A postman butterfly feeds on a bloom in the Tennessee Aquarium’s Butterfly Garden in Chattanooga. At any one time, the garden may host 1,000 to 1,500 butterflies representing more than 200 species. Courtesy Tennessee Aquarium

Butterflies are back at the Tennessee Aquarium after pandemic bottleneck

Some of the Tennessee Aquarium’s most entrancing, cherished residents — and there are literally thousands of them — have been absent for more than a year and a half.

The aquarium has been unable to source butterflies to fill the Ocean Journey building’s Butterfly Garden since early 2020 because of supply chain disruptions.

The butterflies typically originate from Costa Rica. Every week, about 500 butterfly chrysalises — the life stage between caterpillars and full-fledged adults — are delivered to the aquarium. By raising specific plants, Costa Rican farmers can attract butterflies that use the plants as egg-laying sites and feeding sources for their offspring. By collecting and shipping chrysalises to facilities like the aquarium, farmers can earn a reliable income without resorting to destructive agricultural practices that threaten their country’s rainforests.

And just in time for the holidays, the Tennessee Aquarium’s Butterfly Garden will reopen to the public Nov. 5. This warm, light-filled gallery in Chattanooga is once again filled with these jewel-like insects, which flutter in the air by the hundreds.

“They have so many bright colors and intricate patterns that they’re kind of like living works of art,” said entomologist II Rose Segbers. “The butterfly garden is special because it’s completely immersive. There really aren’t any barriers between guests and the butterflies or the habitat.

“You can see everything just like you would in nature, and a butterfly might even land on you.”

Walking through the garden is like being whisked into the steamy, lush wilds of a Costa Rican rainforest. The interior of the gallery is always kept warm and humid — a welcome escape from the cooler, dreary days of autumn — and seemingly every leaf, blossom and branch serves as temporary resting spot for butterflies of every description.

At any one time, the garden houses as many as 1,500 butterflies. These can come from any of more than two dozen species, from cerulean-winged blue morphos to enormous tawny owls with their tell-tale eyespots. 

“You get a lot of variety in here,” Segbers said. “If you come here one week, you’ll see a certain variety of butterflies, but if you come back a week later, you might see completely different ones. It gives people a good excuse to keep coming back.”

The cocoon-like chrysalises can be viewed hanging from racks through a special viewing window in the garden. Their shells often look drastically different from the butterflies within. Who would suspect that the familiar orange, black and white monarch butterfly would come from a gold-fringed, jade chrysalis or that leaf-like pink or green chrysalises are host to brilliant yellow cloudless sulfurs?

Entomologist Rose Segbers pins blue morpho butterfly pupae to a hanging tray, where they will hang until they emerge in a few weeks time. Courtesy Tennessee Aquarium

Charles Henry Turner

The University of Tennessee One Health Initiative will host an impressive array of climate-related discussions, presentations and museum tours Wednesday, Nov. 3, at the UT Student Union on Cumberland Avenue in Knoxville. A virtual option is also available for the day-long event, which is affiliated with the 6th Annual World One Health Day.

The day will feature a “One Health and Climate Change” expert panel discussion, which is set for noon and includes perspectives ranging from the UT Institute of Agriculture to Oak Ridge National Laboratory.

A kayak outing and trash cleanup along the Tennessee River and its tributaries are also planned, as is a tour of UT Gardens, and the herbarium. McClung Museum at Circle Park will offer up its freshwater mussel collection for closer inspection and host a tour examining archaeology findings related to the indigenous inhabitants of Tennessee.

Check out University of Tennessee One Health Day for a full schedule and more information.

This view from Heintooga Ridge Road offers a good vantage point to absorb the brilliant fall colors breaking out across the mountains in North Carolina in Great Smoky Mountains National Park. Research indicates the reliable fall color regime in the Southern Appalachians is affected by climate change.  Courtesy National Park Service

It’s just the latest way humans have altered Appalachian forests

This story originally appeared in the Conversation. Marc Abrams is a professor of forest ecology and physiology at Penn State.

Fall foliage season is a calendar highlight in states from Maine south to Georgia and west to the Rocky Mountains. It’s especially important in the Northeast, where fall colors attract an estimated US$8 billion in tourism revenues to New England every year.

As a forestry scientist, I’m often asked how climate change is affecting fall foliage displays. What’s clearest so far is that color changes are occurring later in the season. And the persistence of very warm, wet weather in 2021 is reducing color displays in the Northeast and mid-Atlantic. But climate change isn’t the only factor at work, and in some areas, human decisions about forest management are the biggest influences.

Longer growing seasons

Climate change is clearly making the Northeast warmer and wetter. Since 1980, average temperatures in the Northeast have increased by 0.66 degrees Fahrenheit (0.37 Celsius), and average annual precipitation has increased by 3.4 inches (8.6 centimeters) — about 8 percent. This increase in precipitation fuels tree growth and tends to offset stress on the trees from rising temperatures. In the West, which is becoming both warmer and drier, climate change is having greater physiological effects on trees.

My research in tree physiology and dendrochronology — dating and interpreting past events based on trees’ growth rings — shows that in general, trees in the eastern U.S. have fared quite well in a changing climate. That’s not surprising given the subtle variations in climate across much of the eastern U.S. Temperature often limits trees’ growth in cool and cold regions, so the trees usually benefit from slight warming

In addition, carbon dioxide — the dominant greenhouse gas warming Earth’s climate — is also the molecule that fuels photosynthesis in plants. As carbon dioxide concentrations in the atmosphere increase, plants carry out more photosynthesis and grow more.