Newswise — Smokestacks spewing black plumes. Car traffic inching along an eight-lane freeway. An ominous haze drifting from a blazing wildfire. These are common sights in California—and all major contributors to climate change.
Since the beginning of the Industrial Revolution, humans have increased the amount of carbon in the atmosphere by 47 percent through activities like burning fossil fuels and deforestation. Along with other gases, concentrated carbon traps heat in the atmosphere, causing the earth to warm, commonly known as the “greenhouse effect.” As the planet heats up, it is experiencing myriad harmful effects, including extreme weather, droughts, wildfires and rising sea levels from melting glaciers and ice sheets.
Experts across the world, including at the CSU, engage in research to help people adapt to the resulting upheaval—from protecting the ocean to responding to wildfires. But to truly save the earth, efforts also need to mitigate climate change by addressing the cause of the problem: greenhouse gas emissions.
The global community has made strides to address its emissions, with 197 countries, including the United States, signing onto the Paris Agreement to reduce emissions; in fact, California itself has committed to becoming carbon neutral by 2045. According to new research published in Science magazine, California already reduced its emissions by 78 percent between 1990 and 2014, the most of any state. But the world continues to find itself in the midst of a climate emergency and besieged by the catastrophic results of climate change.
To aid in the efforts to mitigate the climate crisis, CSU faculty and students are finding ways to further curtail emissions and extract carbon from the atmosphere.
Trapped Underground Cal State East Bay
Human development and fires are damaging and destroying the globe's natural habitats, but its plant life may be most helpful in healing the earth's carbon-choked atmosphere. During photosynthesis, plants take in carbon dioxide (CO2) from the air and store it underground—effectively removing carbon from the atmosphere.
Patty Oikawa, Ph.D., assistant professor of earth and environmental studies at California State University, East Bay, is studying a habitat that is particularly effective at this carbon sequestration process: wetlands.
“In most ecosystems, that biomass stays there for a little while but then it decomposes; it just breaks down and turns back into CO2 and goes back into the atmosphere," Dr. Oikawa says. “But in wetlands, they're unique in the sense that they're flooded, and the water makes the soils anoxic—so there's no oxygen in the soils. … Whenever that plant biomass dies, it tends not to break down. It just stays there. And the carbon then builds up over time, and you can get carbon stored there for thousands of years."
Focusing on the Eden Landing Ecological Reserve on the San Francisco Bay—one of the country's largest wetlands restoration projects—Oikawa is quantifying the amount of carbon sequestered by these wetlands using an Eddy Covariance Flux Tower, which measures the amount of carbon in the air. But she's also testing the amount of carbon being exchanged between the wetland and the ocean in the tides.
“We can see how much carbon the wetland is extracting from the atmosphere and where it's going," she says. “Is it staying there, is it in the soil or is it being transported out into the bay? Then we can also measure our soils, go back in time and look at how much soil is being stored and built up over time, and relate that with sea level rise."
The research is particularly helpful for industries participating in California's Cap-and-Trade Program—which sets a maximum on greenhouse gas emissions, but allows companies to counteract their emissions by investing in projects that reduce carbon, fundamentally creating a “carbon market." Oikawa's team developed protocols for the San Francisco Bay Delta and Sacramento-San Joaquin River Delta, currently being considered by the California Air Resources Board, for how industries can invest in these wetlands to make this exchange.
“This is providing an avenue for some people to build wetlands that wouldn't otherwise be restored or built, and they can help finance that restoration through these carbon markets," Oikawa explains.
In addition, she is studying ways to increase carbon sequestration in California's range and grasslands. At several sites throughout the state, her team has applied a quarter inch of compost made from excess waste like food and manure to lands where ranchers graze their cattle. Already, the compost has helped the plants grow bigger and greener and is allowing them to store more carbon underground.
“Wetlands store a lot more carbon and are really good at it, but they encompass a small fraction of the land surface," she says. “So even though we're talking about a lot smaller carbon sequestration on range lands, they cover 40 percent of the land surface and actually have a bigger potential impact. Plus, you have the added benefit of reusing some of our waste streams, which is a problem anyway from a greenhouse gas perspective."
Ultimately, the aim is to find more ways to meet the state, country and global carbon emission goals. “We need to figure out what our options are for this active removal from the atmosphere," Oikawa says. “There's not just going to be one negative emission technology. Every location, every nation is going to have to address this with their own ideas."
Floating in the Air Cal State Fullerton
One cause of global warming arises from dark carbon particles in the air absorbing the sunlight entering the atmosphere rather than reflecting it back into space. As the particles accumulate, they absorb more light and heat, warming the earth further. While there has been a good amount of research on how black carbon, like soot particles emitted by semitrucks, intensifies the warming effect, not as much has been done on brown carbon, like smog or smoke.
“People have been studying climate change for decades, but this is a solvable problem," says Daniel Curtis, Ph.D., associate professor of analytical chemistry at California State University, Fullerton. “It's going to take a lot of effort, and it's going to be a global effort for us to figure this out. We have all these examples of where mitigation has worked in the past, and so we would like to apply that mitigation to this problem."
Dr. Curtis's research on brown carbon focuses on how these aerosol particles directly interact with sunlight. In the lab, he and his students have developed instrumentation that will allow him to create brown carbon aerosols, shine light on them and measure whether they absorb or scatter the light.
“The first step is always understanding," he says. “We want to know what these particles do when they're in the atmosphere. Once we learn that, we can start to figure out if there are different ways of dealing with climate change."
Paula Hudson, Ph.D., associate professor of analytical chemistry, builds on Curtis's research by studying how these particles absorb water and form clouds that then interact with light. She brings together the brown carbon aerosols with water vapor in her lab instruments and measures how much water the particles have absorbed using a microbalance. This information tells her and her students whether the aerosols will form clouds that reflect light, which cool the earth.
During the past year, she and her students conducted the experiment and found that over time, the particles become darker while maintaining the same level of water uptake. This means the particles will increasingly absorb more light without forming clouds that will increasingly reflect more light, resulting in a net warming effect. The next step will be testing the aerosols after introducing other substances from the atmosphere into the lab setting.
“If we know this type of aerosol has this type of effect, then you go back to policymakers and say, for example, 'We need to install scrubbers on our smokestacks' or 'We need to reduce the total net particle output from diesel vehicles,'" Dr. Hudson says.
But the solution to reducing brown carbon may be more difficult to come by, she explains. “Now that we're looking at these particles that are generated from natural processes like forest fires, then it becomes a huge cyclical problem—because everything is warming, we're having more forest fires and we're creating more particles, which are creating more warming. Then they are also forming clouds that, although highly reflective, don't produce rain and cause a lot of local drought situations as well, which is then self-perpetuating. … We want to understand the effect these particles have because if it really comes down to needing to reduce the number of forest fires, then let's address that question just like we address reducing output from diesel vehicles or smokestacks."
Towering over the Land CSU Bakersfield
California State University, Bakersfield recently installed an Eddy Covariance Flux Tower on campus that can measure the carbon and water vapor flowing in and out of the local landscape. The hope is the tower can contribute to a wide range of interdisciplinary climate change research projects—from biology and computer science experiments to measuring the effectiveness of the campus's sustainability efforts.
“It's continuously running and will now become a long-term monitoring station. As CO2 in the atmosphere is increasing, we'll pick that up year after year," says Biology Professor Anna Jacobsen, Ph.D., who co-directed the grant funding the tower. “We have opportunities for our students to do things that connect them in a tangible way to a broader scientific effort to monitor terrestrial photosynthesis and respiration patterns, CO2 production and atmospheric CO2."
Biology Professor Brandon Pratt, Ph.D., a driving force behind acquiring the tower, is already putting its measurements to use as he studies carbon sequestration in native California shrublands, called chaparral, and the grasslands that have replaced them. His research will help the state understand how its changing ecosystems could affect climate change.
“In the last 50 to 100 years, we've lost about 20 to 30 percent of those shrublands … in wild land areas, national forests or national parks like in the Santa Monica Mountains," he says. “These are areas that have for various reasons been converted into grasslands, and the dominant reason seems to be changing fire dynamics on these landscapes."
The shrublands can tolerate fires every 20 to 50 years—but with fires occurring more frequently, chaparral are giving way to grasses and small herbs that dry out more quickly and increase regional temperatures, worsening drought and fire conditions. These grasslands, though, don't store as much carbon as the chaparral ecosystems and may even be sources of carbon.
To test the climate effects of these two habitats, Dr. Pratt has planted two plots on the campus's outdoor Environmental Studies Area—one with shrubs, one with grasses—and will manipulate the watering to simulate drought conditions. The tower will then record the carbon levels emitting from both plots.
He's also waiting on approval for another grant that would allow him to install more towers throughout Southern California to do similar monitoring in natural environments. “We want to … ask: What is this doing to the regional carbon, both in terms of storage and source-sink dynamics, as you're losing shrubland and going to grassland?" Pratt says. “But, of course, CO2 doesn't stay in place. It blows all over the globe, so this is really a global question and a global issue."
His research will also support ongoing restoration efforts on chaparral that has been fully or partially converted to grasslands. State conservationists are currently working on restoring areas that are unlikely to burn frequently, have high biodiversity and help prevent erosion and landslides.
“The timing is absolutely perfect to start asking what to do about the shrublands because the motivation is there and people are working on this now for the first time," Pratt explains. “The conservation biologists, the land managers with the Forest Service and the National Park Service are getting serious about this, and they have some funds to back it up. We're getting this research coming in telling us the scope of the problem, that it's bigger than we thought it was. And then we're having these droughts, and it's exacerbating the problem. So, it just feels like everything is coming to a head."
Down by the Ocean Cal Poly San Luis Obispo
The vast blue expanse of the ocean is an awe-inspiring sight to behold. In its waves and along its shores, though, may lie answers to scientists' pressing climate change questions—from renewable energy production to carbon sequestration to sustainable agriculture.
Benjamin Ruttenberg, Ph.D., associate professor and director of the Center for Coastal Marine Sciences at California Polytechnic State University, San Luis Obispo, is asking those questions.
“Climate change is here and it's here now—so we have to do absolutely everything we possibly can as soon as we possibly can to try to reduce how much CO2 we're putting in the atmosphere," Dr. Ruttenberg says. “To mitigate the effects of climate change, we need an 'all-of-the-above' strategy. We need to do everything better now. And I believe if we have the right policies, we can do that."
Because a major source of carbon is energy production, renewable energy like solar or wind must be part of the solution. With one project, Ruttenberg is looking at the viability of offshore wind energy and placing wind turbines on floating structures along the California coast. This involves identifying locations with the greatest amount of wind, modeling how much wind power would be produced by a turbine in a particular area and determining if wind power production aligns with demand for energy.
“One of the questions [we're testing is] how well is offshore wind energy complementary to solar," Ruttenberg says. “When we look at the relative value of offshore wind, it seems to peak in the late afternoon—especially in spring and summer—when demand for electricity is highest, just as solar power production winds down."
The next challenge is understanding the potential impacts of the turbines on the environment, marine mammals, seabirds and fisheries. A journal recently accepted a paper led by former undergraduate student Hayley Farr, B.S. biological science, '18, looking at the environmental impacts from similar types of facilities and equipment, such as fixed bottom offshore wind facilities, floating oil and gas platforms and fishing gear. It found such facilities are likely to have low or mitigable impacts on many aspects of the environment.
Some preliminary research has also begun looking at technology to harness tidal and wave power, but Ruttenberg explains it is still in the early stages.
In addition, Ruttenberg is studying aquaculture to develop sustainable seafood farming methods that produce less carbon and minimize ocean acidification (the result of increased carbon dioxide in the water).
About half the world's seafood is produced through aquaculture, but it's often done with deleterious environmental effects, such as clearing habitats that store carbon and filter the water and adding excess feed that produces waste and eats up the available oxygen. Aquaculture then becomes another carbon-producing industry increasing the amount of CO2 in the atmosphere and ocean.
“We've maxed out what the oceans can produce in terms of fishing—so if we want to continue eating seafood, we're going to have to figure out how to grow it," Ruttenberg says.
While working with Sea Grant Fellow Kevin Johnson, Ph.D., on growing oysters that are more resistant to ocean acidification, Ruttenberg is also researching carbon-neutral aquaculture methods for oysters, native Pismo clams and abalone. He and a team of scientists from four universities have proposed a project to grow algae, abalone and oysters together. The algae would feed the abalone, buffer it from ocean acidification and consume carbon dioxide while the oysters would filter waste out of the water.
“Our goal is to try to make it as self-sustaining as possible," Ruttenberg says. “Essentially the only input to the system is electricity, and if we can figure out a way to offset the cost of electricity by putting in offshore wind or solar, then essentially you have a facility that's producing all this food with no carbon footprint."
Ruttenberg's research is just a sampling of the ongoing work being done by Cal Poly San Luis Obispo experts to address climate change. The campus's new Institute of Climate Leadership and Resilience (ICLR), which will coordinate the research, also includes projects to study carbon sequestration, redesign former power plants to produce renewable energy and develop a resilient energy assessment toolkit to help low-capacity cities implement microgrids and sustainable energy production.
Erin Pearse, associate professor of mathematics spearheading ICLR's development, explains the collaboration will also introduce climate research into the classroom.
“We're bringing community-based climate projects onto the Cal Poly campus through project-based courses, senior projects or graduate theses so that student groups can develop designs and/or perform analysis of existing designs," Pearse says.
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