Duke Research Blog

Following the people and events that make up the research community at Duke.

Category: Climate/Global Change (Page 1 of 5)

Linking Climate Change, Air Pollution and Public Health

We often view climate change and air pollution as two separate entities. But, the two issues are united by one common driving factor: human emissions. Nicholas School of the Environment Earth Sciences Professor Drew Shindell reminds us how interconnected these issues truly are, and how we must begin viewing them as such to create change.

Shindell argues that climate change and air pollution are often misrepresented. Air pollution is a problem that seems elusive to the individual, and yet it is the

Dr. Shindell with Marcelo Mena (far left), Vice Minister of the Environment of Chile, and Governor Jerry Brown (CA) at the COP21 in Paris.

number one cause of premature death. The problem is often polarized from us, and we forget that we are largely at fault for its increasing effect. We place the blame on the emissions of large corporations, when our own car emissions are just as detrimental. Shindell argues that it is the “othering” of these issues that makes it hard for us feel a need to create change.

But, by clearly linking climate change and air pollution together, and linking those two to human health, Shindell believes we will develop a greater sense of responsibility for our environment. He gives the example of Pakistan, where increased ozone levels due to human emissions have severely decreased the air quality. As a result, there has been a 36% decline wheat and rice production. This dent in Pakistan’s agricultural systems poses a great threat on food security for the entire nation, and could potentially create a wave of health issues.

But policy often blurs the line between air pollution, climate change and human health. Shindell says he doesn’t know of a single jurisdiction that explicitly mentions the scope of negative effects air pollution and climate change can have on our health (stroke, lung cancer, new disease vectors, to name a few). He suggests expanding our metrics and developing a broader-based impact analysis so that humans are well-informed of the interconnectedness of these issues.

Is it easier to blame a big factory for pollution than to look at your own travel habits?

If we included public health in our impact estimates for methane emissions, for example, the cost would be much larger than anticipated. But, Shindell highlights that to bring these emissions down requires a change that is not easy to ask of our energy-dependent, consumer-driven world. Decreasing our meat consumption by 48%, for example, would save us billions of dollars, but to trigger such a change would demand a desire from the public to alter their behavior, which time and time again has proven to be challenging.

At the end of the day, this scientific issue is a largely psychological one. We assume our contributions make a negligible difference, when in reality it is our consumer behavior that will drive the change we wish to see in our environment. But, how are we expected to feel the burden of air pollution on our health, when policy isn’t directly linking the two together? How can we see climate change as an issue that threatens the security of global agricultural systems when legislation fails to draw the two together explicitly? It is here where we must see a change.

Post by Lola Sanchez-Carrion


Rooftop Observatory Tracks Hurricane Rain and Winter Snow

Jonathan Holt replaces the protective cover over the rain gauge.

Jonathan Holt replaces the protective cover over the rain gauge.

On Friday night, while most of North Carolina braced against the biting sleet and snow with hot cocoa and Netflix, a suite of research instruments stood tall above Duke’s campus, quietly gathering data on the the storm.

The instruments are part of a new miniature cloud and precipitation-monitoring laboratory installed on the roof of Fitzpatrick CIEMAS by graduate student Jonathan Holt and fellow climate researchers in Ana Barros’s lab.

The team got the instruments up and running in early October, just in time for their rain gauge to register a whooping six inches of rain in six hours at the height of Hurricane Matthew — an accumulation rate comparable to that of Hurricane Katrina when it made landfall in Mississippi. Last weekend, they collected similar data on the winter storm, their Micro Rain Radar tracking the rate of snowfall throughout the night.

The rooftop is just the latest location where the Barros group is gathering precipitation data, joining sites in the Great Smokies, the Central Andes of Peru, and Southern Africa. These three instruments, with a fourth added in early January, are designed to continuously track the precipitation rate, the size and shape of raindrops or snow flakes – which climatologists collectively dub hydrometeors — and the formation and height of clouds in the air above Duke.

Ana Barros, a professor of civil and environmental engineering at Duke, says that her team uses these field observations, combined with atmospheric data from institutions like NOAA and NASA, to study how microscopic particles of dust, smoke, or other materials in the air called aerosols interact with water vapor to form clouds and precipitation. Understanding these interactions is a key prerequisite to building accurate weather and climate models.

“What we are trying to do here is to actually follow the lifecycle of water droplets in the air, and understand how that varies depending on weather systems, on conditions, on the climatic region and the location on the landscape,” Barros said.

A distrometer on the roof of Fitzpatrick CIEMAS.

A laser beam passing between the two heads of the distrometer detects the numbers and sizes of passing raindrops or snowflakes.

Besides tracking dramatic events like Matthew, Barros says they are also interested in gathering data on light rainfall, defined as precipitation at a rate of less than 3 mm of an hour, throughout the year. Light rainfall is a significant source of water in the region, comprising about 35 percent of the annual rainfall. Studies have shown that it is particularly prone to climate change because even modest bumps in temperature can cause these small water droplets to evaporate back to gas.

Eliminating this water source, “is not a dramatic change,” Barros said. “But it is one of those very important changes that has implications for how we manage water, how we use water, how we design infrastructure, how we have to actually plan for the future.”

Barros says she is unaware of any similar instrument suites in North Carolina, putting their rooftop site in position to provide unique insights about the region’s climate. And unlike their mountainous field sites, instruments on the roof are less prone to being co-opted by itchy bears.

“When we can gather long term rain gauge data like this, that puts our research group in a really unique position to come up with results that no one else has, and to draw conclusions about climate change that no one else can,” Holt said. “It is fun to have a truly unique perspective into the meteorology, hydrology and weather in this place.”

Micro Rain Radar data from Hurricane Matthew and the snowstorm on Jan. 6th.

The Micro Rain Radar (MRR) shoots radio waves into the sky where they reflect off water droplets or snowflakes, revealing the size and height of clouds or precipitation. The team collected continuous MRR data during Hurricane Matthew (top) and last Friday’s snow storm (bottom), creating these colorful plots that illustrate precipitation rates during the storms.

Kara J. Manke, PhD

Post by Kara Manke

New Blogger: Lola Sanchez-Carrion

Hi! My name is Lola Sanchez-Carrion and I am currently a sophomore at Duke pursuing a double major in Biology and Global Health. I was born in New York, and raised between Miami and Lima, Peru. It was in Lima that I developed a passion for global health, and a strong understanding of the implications scientific research can have on communities like the one I lived in.

New Blogger Lola Sanchez-Carrion is a sophomore in pre-med.

New Blogger Lola Sanchez-Carrion is a sophomore in pre-med.

Throughout high school, I did volunteer work with “TECHO,” an NGO that works towards mitigating poverty by building emergency relief homes, improving health systems, and encouraging political advocacy in developing regions of South America. By working with this organization and interacting with communities on a personal level, I began taking greater notice of global health issues and the need to address them.

I was so moved by my experiences with TECHO that I wrote an article about it for an online publication for international schools, and in doing so another interest emerged: a desire to write about all things health/science-related. I wrote for my high school’s “Environmental Science Blog,” a medium through which student writers showcased conferences and events taking place on campus and around Lima regarding environmental activism. I organized a conference on climate change at my high school to instigate conversations on scientific topics relevant to those of my generation. I realized the power that one’s words, written and verbal, had on teaching and inspiring others, particularly those outside the realms of the “scientific community.”

I am currently on the pre-med track at Duke, but am still very much open to the idea of following a scientific career that does not entail pursuing a medical degree. My courses in Global Health, particularly classes taught by Dr. Broverman and Dr. Whetten, have allowed me to recognized the infinite opportunities that exist through research at Duke, and how tangible the impact from research really is.

I hope that by writing for the Duke Research Blog, I will get to experience this research hands-on, meet the interesting students and faculty behind the cutting-edge work, and share it with other members of the Duke community so that they too can experience that impact.

Apart from my work with the Duke Research Blog, I am a tour guide on campus and am a member of Duke’s WISER Club, an organization that works towards empowering and educating women in rural Kenya.

An Unconventional Career Map

Landscape ecologist Jennifer Swenson has a very special set of skills that come from having an “unconventional academic trajectory.”


Jennifer Swenson is an associate professor of the practice in geospatial analysis at the Nicholas School of the Environment

Her diverse and interesting career began at UC Santa Barbara, where she chose to learn about International Relations and Geography. “I wanted to be versatile and globally aware,” she said. Undergraduate school is where she learned the geography techniques she now uses in her research,  and received stacks of reading for international relations.

After this, Swenson spent three years giving bicycle tours, working at a ski resort, and other jobs, until she went on a conservation trip to Ecuador to work for an NGO (non-governmental organization). She was able to use her geospatial techniques (GIS) to map trails and land cover change in Ecuadorian national parks, and also to evaluate forest corridors for an endangered species of monkey.

Connectivity between habitat remnants for critically endangered primate, Callicebus oenanthe, in San Martin, Peru. Presented at the 2nd Simposio de Primatologia en el Peru (Iquitos, November 2013) & at the Remote Sensing forConservation Symposium (London, May 2014) Schaffer-Smith, Swenson, Bóveda-Penalba, Murrieta-Villalobos

Connectivity between habitat remnants for critically endangered primate, Callicebus oenanthe, in San Martin, Peru. Presented at the 2nd Simposio de Primatologia en el Peru (Iquitos, November 2013) & at the Remote Sensing forConservation Symposium (London, May 2014) Schaffer-Smith, Swenson, Bóveda-Penalba, Murrieta-Villalobos

She learned many things, including how to manage a lab, and also became fluent in Spanish thanks to the total immersion. “It’s just another barrier,” she says, to have to use English. Plus, it is useful for reading papers that haven’t been translated.

“Everyone should learn a second or third language and have the opportunity to be immersed in that country.”

After this she went back to graduate school and got a Ph.D. in forest science at Oregon State.

Swenson’s research at Duke is often about conservation or biodiversity, and occasionally ecosystem studies. She is still using her special skills to try to do the greatest good.

“Its great to work towards that, but sometimes its hard to detect that you are doing change,” she says. “I still keep trying to forge ahead and do whatever I can for the environment. In the end, all those students that we train and send out will do great things, and that’s how we have the greatest impact for the environment.”

CalebCaton_100Guest Post by Caleb Caton, a senior at the North Carolina School of Science and Math

Checking in on Air Pollution — With an Expert!

I had the pleasure of meeting and interviewing Duke Professor Junfeng “Jim” Zhang, an avid environmental health researcher who has done amazing work on air pollution research. Because of my own interest in air pollution and its adverse health effects, I began by trying to grasp Dr. Zhang’s work through his detailed scientific explanations of his projects, such as looking at the human health effects of nano-technology.

Junfeng (Jim) Zhang is a professor of global and environmental health in the Nicholas School and the Duke Global Health Institute

Junfeng (Jim) Zhang is a professor of global and environmental health in the Nicholas School and the Duke Global Health Institute

From my reading on the projects I was interested in, I did not expect Zhang to be able to step back and capture the importance of his research in simple terms because his projects were quite complicated (such as testing human health effects due to chemically altered diesel fuel). However, it turned out that Zhang is well-versed in communicating both crucial details of his research and the overall meaning for human health.

The most captivating aspect of my interview with Zhang was our discussion of his contribution to the 2007 Nobel Peace Prize, which was awarded to the Intergovernmental Panel on Climate Change. Dr. Zhang essentially concluded that burning and replanting trees is not necessarily carbon-neutral, disproving the common view that replanting burned trees is always carbon-neutral. His arguments really sold the importance of his research to me and I very quickly agreed with his views on the consequences of his research.

My interview with Zhang also revealed just how important scientific research is in adding evidence and findings to support a side on the growing global issues of environmental pollution and protection. It really amazed me how researchers play such a crucial supportive role in not only protecting the world’s environment, but advancing the quality of human life.

UPDATE – Professor Zhang spoke with BBC about air pollution in China. Read the story here.

PeterChengGuest Post by Peter Cheng, a senior at the North Carolina School of Science and Math.

Seeing the Research for the Trees

The Duke Forest is more than just a place to run the trails or harvest timber. It’s also an important living laboratory for Duke’s research community.

On Dec. 4, we joined the annual tour of research sites in the 7,000-acre forest, led by forest Director Sara Childs and Operations Manager Jenna Schreiber. Nearly two dozen of us learned about water and bugs, climate change and nanoparticle pollution.

Maggie Zimmer opened up the equipment box for her show and tell of the hydrology experiment.

Maggie Zimmer opened up the equipment box for her show and tell of the hydrology experiment.

At the first stop, in the Edeburn Division south of Hillsborough, Nicholas School graduate student Maggie Zimmer showed us a densely instrumented watershed for studying how a raindrop reaches a stream.  A little valley of 130 hectares is studded with wells and dammed by a weir that measures every drop flowing out of the watershed. Zimmer and her thesis advisor Brian McGlynn are trying to get a handle on how a drop of water falling on a leaf or the ground eventually makes its way through several feet of soil and clay, in and around chunks of old rock, to the stream.

It’s not as simple as you think, says Zimmer, who has hand-augured 35 test wells in the study area and spent many dark, wet nights tending to her delicate equipment. For example, the rain gauge measures .01 millimeters at a time!

Across the road from the hydrology lab, we visited a global warming forest built by Jim Clark’s research team and overseen by lab manager Jordan Siminitz.

Jordan Siminitz showed us inside one of the warming forest test chambers.

Jordan Siminitz showed us inside one of the warming forest test chambers.

There are 24 plastic enclosures for studying how temperature increases in the soil might affect the growth of young trees. The warming scenarios were produced by a network of propane-heated pipes under the soil in each enclosure. The funding that built the site and operated it for four years has stopped, but the trees are still there and the team is hopeful they can restart the experiment.

Here and in Harvard Forest, the team was looking at soil temperature increases of 3 degrees or 5 degrees Celsius. The surprising finding out of four years of data was that southern tree species seemed to be more adversely affected by the temperature increase than northern species.

“Long term research like this is really hard to get funding for,” Childs said. But without long term studies, we won’t know much about what to expect from climate change. Incidentally, NC State was conducting a parallel study of ants and warmer soils in the same experimental booths, but they’ll be shutting down this year as well.

Duke Forest Director Sara Childs checked out a pickled Southern Pine Beetle.

Duke Forest Director Sara Childs checked out a pickled Southern Pine Beetle.

At the next stop, we found nattily uniformed NC Forest Service ranger Philip Ramsey standing next to an elaborate plastic contraption like 10 black funnels in a series leading down to a reservoir of antifreeze at the bottom. It’s a pheromone trap for the Southern Pine Beetle and its predator, the Clerid beetle. All is well with those bugs for now, but the devastating enemy of ash trees, the Emerald Ash Borer, is on the march and due to arrive any month now, Ramsey said, passing around pickled specimens of the bugs for our inspection.

Our last stop was an update on the nanotechnology test site called the mesocosm  facility – 30 boxes filled with water, silt and plant life. They’re meant to mimic a tiny slice of a shoreline ecosystem to see how various nanoparticle materials are taken up by plant and animal life.

Steve Anderson (at right) explained the mesocosm test chambers to the tour group.

Steve Anderson (at right) explained the mesocosm test chambers to the tour group.

Research analyst Steve Anderson from Emily Bernhardt’s lab explained the latest experiments on what happens to all the poisonous stuff infused into anti-bacterial socks and pressure-treated lumber. The good news so far is that nanoparticies don’t seem to get taken up by ecosystems as readily as some had feared.

This isn’t really forest research per se, but where else are you going to put 30 big bunkers of mud, surrounded by an electrified raccoon fence, a super-fine frog fence and a Quonset hut enclosure for the cooler months?

Duke Forest houses 71 research projects at the moment, 16 of them started in just the last year. We’ll look forward to more fun discoveries on next year’s tour!

Follow Duke Forest on Facebook or subscribe to their updates to catch this and other tours.

Karl Leif Bates

Post by Karl Leif Bates

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