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carbon dioxide

Braving the bugs, Alistair Rogers (right) and his colleague Stefanie Lasota collect leaf samples in Alaska for analysis. Photo by Roy Kaltschmidt

By Daniel Dunaief

Alistair Rogers lives, thinks and works on opposite extremes.

At the same time that he gathers information from the frigid Arctic, he is also analyzing data from the sweltering tropical forests of Panama and Brazil. He visits both regions annually and, within one eight-day span, saw a Polar Bear in Utqiaġvik (formerly known as Barrow), Alaska and a tarantula in Brazil.

Alistair Rogers. Photo from BNL

That’s not where the extremes end. Rogers is also studying plants at the physiological level to understand how best to represent processes such as photosynthesis, respiration and stomatal conductance in climate models.

The leader of the Terrestrial Ecosystem Science & Technology Group in the Environmental and Climate Sciences Department at Brookhaven National Laboratory, Rogers recently was honored as a Fellow of the American Association for the Advancement of Science.

The AAAS has named fellows every year since 1874 to recognize their contributions to the advancement of science. Previous honorees included astronaut and former Johnson Space Center Director Ellen Ochoa, a founding member of the NAACP and scholar W.E.B. Du Bois and inventor Thomas Edison.

Lisa Ainsworth, Research Leaders of the Global Change in Photosynthesis Unit for the USDA Research Service, nominated Rogers, who served as a mentor for her when she conducted her PhD research.

“[Rogers] is one of the world’s authorities on understanding how plants respond to atmospheric change and in particular rising carbon dioxide concentration,” Ainsworth said. He’s an experimentalist who “built a bridge to the scientific computational modeling community.”

Ainsworth suggested she would not have the career she developed if it weren’t for the support she received from Rogers.

Rogers, who the Department of Energy recognized as an Outstanding Mentor three times and has been at BNL since 1998, “makes you believe in yourself when you don’t have any reason to do that. He believes in you before you know you should believe in yourself,” Ainsworth said. For his part, Rogers is “delighted to be honored and recognized as a fellow.”

Carbon dioxide sinks

For all the extremes in his work, Rogers has been collecting data from plants to address a range of questions, including how they will react to and affect environmental changes caused by global warming.

Through photosynthesis, plants are responsible for absorbing about a third of the carbon dioxide humans produce through the burning of fossil fuels.

The uptake of carbon dioxide by plants and oceans has limited warming so far to 1.2 degrees Celsius above pre-Industrial temperatures. Without such carbon dioxide removal by oceans and plants, the temperature would already be 3 degrees warmer.

The models his work informs are trying to understand what will happen to the carbon dioxide subsidy in the future.

“In order to work out how warm it’s going to get, you need to know the carbon dioxide concentration and the climate sensitivity (how much warmer it will get for a given amount of carbon dioxide),” he explained in an email.

Photosynthesis is less efficient at higher temperatures, but is also more efficient amid an increased amount of carbon dioxide. Drier air also reduces the efficiency of the process as plants close their stomata to conserve water, which restricts carbon dioxide supply to their chloroplasts.

The transfer of water from land to the atmosphere most often occurs through stomata, so understanding the way these pores open and close is important in predicting cloud formation and other land-atmosphere interactions.

Ainsworth described how a typical day of field work gathering data could last for 16 hours. She appreciated how Rogers worked and played hard — he is a cyclist and a skier — while keeping the work fun. Indeed, Ainsworth said Rogers, on regular calls with two other professors, blends discussions about grants and work decisions with their first choice for their guesses at the New York Times wordle game.

Leadership roles

In addition to his leadership role at BNL, Rogers is also part of the leadership teams for the Next Generation Ecosystem Experiment — Arctic and the Next Generation Ecosystem Experiment —Tropics.

Rogers said the Arctic is seeing the biggest increase in temperature relative to anywhere else on the planet faster because of climate feedback. When ice and snow melt, it reveals surfaces that absorb more heat.

The tropics, meanwhile, have been more stable, although the region is expected to experience hotter, drier temperatures in the coming decades as well.

Alistair Rogers. Photo from BNL

The Department of Energy is studying these biomes because they are climatically sensitive, globally important and poorly represented in climate models.

Rogers is working with other scientists at BNL and around the world to understand these processes to feed his data collection and analysis into global models.

Using an analogy for developing these models, Rogers suggested trying to predict the time it would take to get to the airport. A traveler would need to know the distance and the mode of transport — whether she was walking, biking or riding in a car.

A model predicting the travel time would make assumptions about how fast a person could go in a car, while factoring in other data like the weather and traffic density at a particular time to anticipate the speed.

If the traffic model wasn’t sure of the maximum possible speed of a vehicle, the error associated with predicting the arrival time could be large, particularly when considering the difference between traveling in a steamroller or a Lamborghini on empty roads.

Climate models use a similar process. By studying the species of plants, Rogers can tell the models whether the plants are the equivalent of sports cars or steamrollers.

Big picture

The worst case scenario of earlier models is highly unlikely, although the scenario of a drastic reduction in carbon dioxide also hasn’t occurred. The models, however, still suggest that changes in human behavior are critical to protecting the future of the planet against the effects of climate change.

Rogers is encouraged by the declining cost of solar energy and the work developing countries have done to bypass some of the more polluting sources of energy from the industrial revolution. He is also pleased by the commitment from the Department of Energy to look for climate change solutions.

These elements “represent great opportunities for scientists like me” to work on these problems.

Qingyun Li. Photo by Xuecheng Chen

By Daniel Dunaief

Qingyun Li has a plan for carbon dioxide.

The newest hire in the Department of Geosciences at Stony Brook University, Li, who is an assistant professor, is a part of a team exploring carbon capture and storage.

“My work is expected to help reduce the amount of carbon dioxide released into the atmosphere,” Li said. It will “help people find ways to promote carbon dioxide mineralization for safer carbon dioxide storage” below the ground. While her work will help promote carbon storage, it doesn’t include capturing and transporting the gas.

By selecting sites carefully, researchers can store carbon dioxide for geologically long periods of time.

While carbon sequestration occurs on the scale of kilometers, Li often works on a minuscule level, at the nanometer to centimeter scale. Smaller scale alterations affect properties such as the permeability of the rock formation.

Li is trying to predict nucleation of a certain mineral in her computer models. She has done that for carbonate minerals, which could be what carbon dioxide becomes after it is stored in geologic formations.

A similar process of nucleation occurs in clouds, when fine particles form the nuclei around which gases condense to form water or ice.

Li used a small angle x-ray scattering synchrotron to explore important details about each particle. This technique, which doesn’t look directly at the particles, reveals through data analysis the particle’s shape, size and surface morphology and, eventually, the rate at which nucleation occurs.

For carbon dioxide sequestration, the minerals that provide nucleation start at the nanoscale, which give them a high specific surface area.

“That matters for later reactions to generate carbonate minerals,” Li said. “That’s one reason we care about the nanoscale phenomenon. The bulk minerals are generated starting from the nanoscale.” 

A larger surface area is necessary in the beginning to lead to the next steps.

Li’s work involves exploring how carbonate starts to form. Her earlier efforts looked at how calcium carbonate forms in the aqueous or water phase.

Carl Steefel, Head of the Geochemistry Department at the Lawrence Berkeley National Laboratory in California, worked with Li during her PhD research at Washington University in St. Louis. Steefel believes her research will prove productive.

“She has an approach to science that combines that one-of-its-kind capabilities for studying nucleation with a deep understanding of modeling and how these open systems involving flow and transport work,” Steefel said. “The combination of these unique capabilities, in nucleating and in understanding reactive transport modeling, will put her a very good position.”

As of now, Li plans to study carbon sequestration in natural gas formations in shale, which has nanometer sized pores. The particles can change the permeability of the rock.

Some companies, like British Petroleum and ExxonMobil, have started to explore this method as a way to reduce their carbon footprint.

While geologic carbon sequestration has shown promising potential, Li believes the process, which she said is still feasible, could be decades away. She said it may need more policy support and economic stimuli to come to fruition.

Part of the challenge is to incorporate such carbon sequestration in the established market.

Scientists working in this field are eager to ensure that the stored carbon dioxide doesn’t somehow return or escape back into the atmosphere.

“People are actively investigating possible leakage possibilities,” Li wrote in an email. “We try to design new materials to build wells that resist” carbon dioxide deterioration.

Controlling pressure and injection rates could prevent various types of leaks.

In her earlier studies, Li explored how cement deteriorates when contacted with carbon dioxide-saturated brine. She hoped to find cracks that had self-healing properties. Other studies investigated this property of concrete.

It’s possible that a mineral could form in a fracture and heal it. In natural shale, scientists sometimes see a fracture filled with a vein of carbonate. Such self healing properties could provide greater reassurance that the carbon dioxide would remain stored in rocks below the surface. Li hopes to manage that to inhibit carbon dioxide leakage.

The assistant professor grew up in Beijing, China, studied chemistry and physics in college. She majored in environmental sciences and is eager to apply what she learned to the real world.

For her PhD, Li conducted research in an engineering department where her advisor Young-Shin Jun at Washington University in St. Louis was working on a project on geologic carbon dioxide sequestration. 

In her post doctoral research at SLAC National Accelerator Laboratory, which is operated by Stanford University, Li explored mineral reactions in shale, extending on the work she did on mineral reactions in concrete as a graduate student. She sought to understand what happens after hydraulic fracturing fluids are injected into shale. These reactions can potentially change how easily the mix of gas and oil flow through a formation.

With Stony Brook building a lab she hopes is finished by next spring, Li plans to hire one graduate student and one post doctoral researcher by next fall.

She is teaching a course related to carbon sequestration this semester and is looking for collaborators not only within geoscience but also within material science and environmental engineering.

Li is looking forward to working with other researchers at the National Synchrotron Lightsource 2 at Brookhaven National Laboratory, which provides beamlines that can allow her to build on her earlier research.

Li and her husband Xuecheng Chen, who are renting an apartment in South Setauket and are looking for a home close to campus, have a three-year old son and an 11-month old daughter.

Outside the lab, Li enjoys quality time with her family. A runner, Li also plays the guzheng, which she described as a wooden box with 21 strings.

Steefel, who wrote a letter to Stony Brook supporting Li’s candidacy to join the Geosciences Department, endorsed her approach to science.

“She’s very focused and directed,” Steefel said. “She’s not running the computer codes as black boxes. She’s trying to understand what’s going on and how that relates to her experiments and to reality.”

By Leah S. Dunaief

Leah Dunaief

Many of us sit through meetings of one kind or another: business meetings, community meetings, even social gatherings. But did you know that the air we breathe in those closed spaces might not be so healthy for us? If you come out of such a gathering and the air around you then feels fresher and cooler, consider this: “Small rooms can build up heat and carbon dioxide from our breath to an extent that might surprise you.”  So explained a recent article in the Science Times section of The New York Times.

When we breathe, we exhale carbon dioxide. That gas, which we might characterize as stale air in such a situation, can actually affect decision-making as a result of its impact on the mind. Some eight studies over the past seven years have considered the effects on cognitive function in small, airless rooms over a couple of hours. The results suggest that perhaps we should not entirely trust decisions made there.

Carbon dioxide, when inhaled, dilates blood vessels in the brain and reduces activity among cerebral neurons, thus decreasing communication between brain regions. We know this to be true when a large amount of the gas is inhaled but we don’t know so much about the effect of smaller amounts. If student test results are compared in rooms with 600 parts per million (ppm)  of CO2 and similar rooms with 2,500 ppm, the scores of the test takers with the high concentration are significantly lower. It is interesting to note that carbon dioxide levels can be twice that high in some classrooms.

Such studies were repeated in the workplace, with workers taking problem-solving and strategy tests, and the results were the same. In today’s energy-sensitive world, many office buildings are better sealed, with less fresh air seeping indoors. Another interesting fact was that not every type of test showed that same result.  Less complex test material, like some proofreading, for example, did not show a comparable shift.

So the next time you are in such a situation, open a window or keep the door ajar. Perhaps the intellectual level of the conversation will rise.

Now here is another tip for better living that is also from The Times, although published a different day. For those of you who, like me, love to sit around sometimes and do nothing, here is exoneration from the charge of laziness in an otherwise busy world. The Times tells us that the Dutch call this “niksen.”

What is doing nothing, exactly? A psychologist named Doreen Dodgen-Magee, who studies this matter, likens it to a car whose engine is running but isn’t going anywhere. It’s “coming to a moment with no plan other than just to be,” she writes. She calls that boredom, which she doesn’t intend in a negative way.

But the idea of niksen is to take conscious time to do activities like gazing out of a window or sitting motionless. I like that, although it flies in the face of our always-be-productive American culture. According to some experts, “the benefits of idleness can be wide-ranging.”

Daydreaming, “an inevitable effect of idleness — literally makes us more creative, better at problem-solving, better at coming up with creative ideas,” according to Sandi Mann, a psychologist at the University of Central Lancashire in England, who has done research in this area. “Let the mind search for its own stimulation. That’s when you get the daydreaming and mind wandering, and that’s when you’re more likely to get the creativity,” she explained.

It’s not easy to do nothing and certainly to do so and not feel guilty about it. We have to set time aside deliberately to disconnect — and not just from our devices. The reward is that we can refocus with more energy. I have a chair in my living room that I can sink into and just have my mind go blank. It’s even tempting to fall asleep there, and sometimes I do for a few minutes.

Delightful!