Methane is a powerful greenhouse gas with strong heat-trapping capabilities. Although there is less methane in the atmosphere than carbon dioxide, the foremost greenhouse gas, researchers attribute . Observations show that methane levels have increased over time, but the factors driving changes in the rate of accumulation remain unclear.

Methane stays in the atmosphere for approximately 10 years before it is broken down, or removed. Researchers need to know how much methane is removed to gauge what percentage of emissions are accumulating in the atmosphere, but the methane removal process is difficult to measure. Historically, researchers have relied on chemistry-climate simulations to predict methane removal, but the accuracy of this approach is debated.

A new 91Ě˝»¨ study presents a value for methane removal in the — the second layer of Earth’s atmosphere — that is based on satellite data. This value, the first derived from observational methods, is higher than the earlier models indicated, suggesting that more methane is broken down in the stratosphere than previously thought.

“Total methane emissions and removal are large values. Their difference, or imbalance, is a small, but critical value. It determines methane trends over time,” said , a 91Ě˝»¨professor of atmospheric and climate science who led the study, on Feb. 9.

Humans are the primary source of . Agriculture, waste and fossil fuels all release methane. Natural sources, such as wetlands, also contribute methane to the atmosphere. Methane “sinks,” including soil and chemical reactions in the atmosphere, remove a large portion of the methane contributed by various sources.

Methane removal takes place in both the troposphere, the closest layer to Earth, and the stratosphere above it. If sources and sinks were balanced, methane wouldn’t accumulate in the atmosphere, but human contributions have .

Methane has become an increasingly popular target for those trying to slow climate change for several reasons. Unlike carbon dioxide, which persists in the atmosphere for hundreds of years, methane breaks down after a decade. Limiting human-related methane emissions could curtail global warming faster than targeting carbon dioxide.

“Methane is a very powerful greenhouse gas with a short lifetime, which gives us more control over it. We will be in a better position, policy-wise, if we understand more about how it accumulates,” Fu said.

There are two ways to calculate methane accumulation in Earth’s atmosphere: One way, a top-down approach, begins with observed methane levels in the atmosphere. The other, a bottom-up strategy, is based on individual sources and sinks on Earth. The trouble is, the two methods don’t agree. Bottom-up calculations indicate that sources exceed sinks by far more than the top-down approach.

In the study, Fu and , a 91Ě˝»¨graduate student in his lab, analyzed publicly available satellite data from 2007 to 2010 to produce a new value for methane removal in the stratosphere. Then, they recalculated the imbalance using this value instead of the model estimates, finding that the bottom-up and top-down results were close to identical.

“Narrowing it down improved our confidence in the methane budget and imbalance estimates, which determines the change in atmospheric methane levels,” Fu said.

That’s not the only benefit, either. Methane reactions in the stratosphere create water vapor, another greenhouse gas, and impact ozone chemistry, impacting the protective ozone layer. These results will help researchers understand the significance of these related reactions.

This study was funded by the Calvin Professorship in Atmospheric Sciences.

For more information, contact Fu at .

UPDATE (Aug. 2, 2024): A previous version of this story misstated Paul Kinahan’s name.

Fifteen faculty members at the 91Ě˝»¨ have been elected to the Washington State Academy of Sciences. They are among 36 scientists and educators from across the state . Selection recognizes the new members’ “outstanding record of scientific and technical achievement, and their willingness to work on behalf of the academy to bring the best available science to bear on issues within the state of Washington.”

Twelve 91Ě˝»¨faculty members were selected by current WSAS members. They are:

• , associate professor of epidemiology, of health systems and population health, and of child, family and population health nursing, who “possesses the rare combination of scientific rigor and courageous commitment to local community health. Identifying original ways to examine questions, and seeking out appropriate scientific methods to study those questions, allow her to translate research to collaborative community interventions with a direct impact on the health of communities.”
• , the Shauna C. Larson endowed chair in learning sciences, for “his work in the cultural basis of scientific research and learning, bringing rigor and light to multiculturalism in science and STEM education through STEM Teaching Tools and other programs.”
• , professor of psychiatry and behavioral sciences, “for her sustained commitment to community-engaged, science-driven practice and policy change related to the prevention of suicide and the promotion of mental health, with a focus on providing effective, sustainable and culturally appropriate care to people with serious mental illness.”
• , the David and Nancy Auth endowed professor in bioengineering, who has “charted new paths for 30-plus years. Her quest to deeply understand protein folding/unfolding and the link to amyloid diseases has propelled her to pioneer unique computational and experimental methods leading to the discovery and characterization of a new protein structure linked to toxicity early in amyloidogenesis.”
• , professor of environmental and occupational health sciences, of global health, and of emergency medicine, who is “a global and national leader at the intersection of climate change and health whose work has advanced our understanding of climate change health effects and has informed the design of preparedness and disaster response planning in Washington state, nationally and globally.”
• , professor of bioengineering and of radiology, who is “recognized for his contributions to the science and engineering of medical imaging systems and for leadership in national programs and professional and scientific societies advancing the capabilities of medical imaging.”
• , the Donald W. and Ruth Mary Close professor of electrical and computer engineering and faculty member in the 91Ě˝»¨Clean Energy Institute, who is “recognized for his distinguished research contributions to the design and operation of economical, reliable and environmentally sustainable power systems, and the development of influential educational materials used to train the next generation of power engineers.”
• , senior vice president and director of the Vaccine and Infectious Disease Division at the Fred Hutchinson Cancer Center, the Joel D. Meyers endowed chair of clinical research and of vaccine and infectious disease at Fred Hutch, and 91Ě˝»¨professor of medicine, who is “is recognized for her seminal contributions to developing validated laboratory methods for interrogating cellular and humoral immune responses to HIV, TB and COVID-19 vaccines, which has led to the analysis of more than 100 vaccine and monoclonal antibody trials for nearly three decades, including evidence of T-cell immune responses as a correlate of vaccine protection.”
• , professor of political science and the Walker family professor for the arts and sciences, who is a specialist “in environmental politics, international political economy, and the politics of nonprofit organizations. He is widely recognized as a leader in the field of environmental politics, best known for his path-breaking research on the role firms and nongovernmental organizations can play in promoting more stringent regulatory standards.”
• , the Ballmer endowed dean of social work, for investigations of “how inequality, in its many forms, affects health, illness and quality of life. He has developed unique conceptual frameworks to investigate how race, ethnicity and immigration are associated with health and social outcomes.”
• , professor of chemistry, who is elected “for distinguished scientific and community contributions to advancing the field of electron paramagnetic resonance spectroscopy, which have transformed how researchers worldwide analyze data.”
• , professor of bioengineering and of ophthalmology, whose “pioneering work in biomedical optics, including the invention of optical microangiography and development of novel imaging technologies, has transformed clinical practice, significantly improving patient outcomes. Through his numerous publications, patents and clinical translations, his research has helped shape the field of biomedical optics.”

Three new 91Ě˝»¨members of the academy were selected by virtue of their previous election to one of the National Academies. They are:

• , professor of atmospheric and climate science, who had been elected to the National Academy of Sciences “for contributions to research and expertise in atmospheric radiation and cloud processes, remote sensing, cloud/aerosol/radiation/climate interactions, stratospheric circulation and stratosphere-troposphere exchanges and coupling, and climate change.”
• , the Bartley Dobb professor for the study and prevention of violence in the Department of Epidemiology and a 91Ě˝»¨professor of pediatrics, who had been elected to the National Academy of Medicine “for being a national public health leader whose innovative and multidisciplinary research to integrate data across the health care system and criminal legal system has deepened our understanding of the risk and consequences of firearm-related harm and informed policies and programs to reduce its burden, especially among underserved communities and populations.”
• , division chief of general pediatrics at Seattle Children’s Hospital and a 91Ě˝»¨professor of pediatrics, who had been elected to the National Academy of Medicine “for her leadership in advancing child health equity through scholarship in community-partnered design of innovative care models in pediatric primary care. Her work has transformed our understanding of how to deliver child preventive health care during the critical early childhood period to achieve equitable health outcomes and reduce disparities.”

In addition, Dr. , president and director of the Fred Hutchinson Cancer Center and of the Cancer Consortium — a partnership between the UW, Seattle Children’s Hospital and Fred Hutch — was elected to the academy for being “part of a research effort that found mutations in the cell-surface protein epidermal growth factor receptor (EGFR), which plays an important role in helping lung cancer cells survive. Today, drugs that target EGFR can dramatically change outcomes for lung cancer patients by slowing the progression of the cancer.”

the Boeing-Egtvedt endowed professor and chair in aeronautics and astronautics, will join the board effective Sept. 30. Morgansen was elected to WSAS in 2021 “for significant advances in nonlinear methods for integrated sensing and control in engineered, bioinspired and biological flight systems,” and “for leadership in cross-disciplinary aerospace workforce development.” She is currently director of the Washington NASA Space Grant Consortium, co-director of the 91Ě˝»¨Space Policy and Research Center and chair of the AIAA Aerospace Department Chairs Association. She is also a member of the WSAS education committee.

“I am excited to serve on the WSAS board and work with WSAS members to leverage and grow WSAS’s impact by identifying new opportunities for WSAS to collaborate and partner with the state in addressing the state’s needs,” said Morgansen.

The new members to the Washington State Academy of Sciences will be formally inducted in September.

In total, there are 120 members in the U.S. and 24 international members added to the academy this year. They bring the total number of active U.S. members to 2,617 and the total number of international members to 537. Membership in the Academy is among the highest honors a scientist can achieve.

, the Calvin professor of atmospheric sciences at the UW, uses satellite observations, ground-based instruments, computer models and theory to explore how clouds affect the climate system, and how changes in different layers of the atmosphere are related to climate change.

Fu earned a bachelor’s and master’s degrees from Beijing University and a doctorate from the University of Utah. He was on the faculty at Canada’s Dalhousie University before joining the 91Ě˝»¨in 2000, where he has been a full professor since 2006.

His previous honors include being named a fellow of the American Association for the Advancement of Science, of the American Geophysical Union and of the American Meteorological Society. He also received the Alexander von Humboldt Research Award and the AMS Jule G. Charney Medal for significant research.

, a professor emeritus of biology at the UW, focuses on evolutionary issues involving the physiology, behavior and ecology of cold-blooded animals, especially of lizards and flies. His recent research has looked at how these animals that rely on external sources of heat will be affected by climate change. Other studies have looked at the effects of altitude on mountaineers, and how baby name trends may be influenced by climate change.

Huey earned a bachelor’s degree from the University of California, Berkeley, a master’s from the University of Texas, Austin, and a doctorate from Harvard University. He joined the 91Ě˝»¨faculty in 1977 and became full professor in 1984. He was chair of the biology department from 2008 to 2011, and retired from teaching in 2014, though he continues to do research.

Huey has been honored as a Miller Research Fellow and as a J. S. Guggenheim Memorial Fellow, and is a past president of the American Society of Naturalists. He was previously elected to the American Academy of Arts & Sciences and to the Washington State Academy of Sciences.

, an affiliate faculty member in biology at the 91Ě˝»¨and faculty member at the University of Texas, Austin, is also among this year’s newly elected members. Torii, who was a core member of the 91Ě˝»¨faculty from 1999 to 2019, studies stem cells and plant development.

The National Academy of Sciences recognizes achievement in science by election to membership, and — along with the National Academy of Engineering and the National Academy of Medicine — provides science, engineering and health policy advice to the federal government and other organizations. All the new members will be formally inducted during the 2025 annual meeting.

The 91Ě˝»¨fellows are:

, professor of atmospheric sciences, was elected for his outstanding contributions to measuring and understanding how radiative heat is transferred through the Earth’s atmosphere, and how this relates to climate and climate change. Fu’s work interpreting satellite data established a key consistency in climate warming in recent decades between the atmosphere and the Earth’s surface. He discovered a shift toward the poles of subtropical jets in a warming climate, showing a widening of the tropics. His parameterization of optical properties of cirrus clouds has been widely used in global climate models. Fu is a fellow of the American Geophysical Union and a fellow of the American Meteorological Society, and holds an affiliate faculty position at China’s Lanzhou University. He earned his doctorate at the University of Utah in 1991 and joined the 91Ě˝»¨in 2000.

, professor of anthropology, was chosen for her contributions at the interface of anthropology, demography and endocrinology, particularly in the areas of hormones and behavior and reproduction across the life span. O’Connor is the director of the UW’s Biological Anthropology and Biodemography Laboratory, which specializes in developing and optimizing collection methods and assays for population-level research in reproductive ecology. O’Connor’s research and teaching interests focus on variation in human fertility and mortality, as well as the biological, cultural and environmental factors that contribute to that variation. In her research on human fertility, O’Connor examines aged-related, population and individual-level variation in female productive function. Her latest research focuses on men’s health, with the goal of understanding the biological and behavioral factors that cause men to have higher mortality rates than women. O’Connor earned her doctorate from the State University of New York at Albany in 1995 and has been a member of the 91Ě˝»¨faculty since 1999.

, professor of pathology, is noted for his work on the biology of longevity. In mammalian cells, he studies physiological and biochemical processes that contribute to a longer, healthier life. His research with transgenic mouse models has increased knowledge of cell signals that delay physical decline. For example, the Rabinovitch lab looks at pathways that might mitigate the aging effects of oxygen metabolism byproducts and of damage to mitochondria, the cell’s powerhouses. Certain chemicals and signaling pathways appear to protect against some debilitations of advancing age: enlargement of the heart, heart failure, loss of muscle tissue and certain cancers. Rabinovitch is the founding director of the 91Ě˝»¨Nathan Shock Center for Excellence in the Basic Biology of Aging, one of five in the country funded by the National Institute on Aging of the National Institutes of Health. He also is a leader in training new scientists in his field. He has received a Senior Scholar in Aging grant from the Ellison Medical Foundation and a Breakthroughs in Gerontology grant from the American Federation for Aging Research. Rabinovitch earned both his doctoral and medical degrees at the UW, and joined the faculty in 1981.

, professor of pharmacology, is interested in the coordination, timing and precision of protein interactions. He studies a small protein called ubiquitin that is found in almost all living things, except primitive lifeforms. Cells use ubiquitin to control activities of many other proteins. This modification — called protein ubiquitination — regulates nearly all biological functions. Problems with protein ubiquitination have been linked to cancer, susceptibility to infection and neurological disorders. Zheng uses X-ray crystallography to visualize the atomic details of protein ubiquitination. His work has suggested new strategies for protecting cells’ antiviral pathways during virus attacks. He also studies how plant hormones and metabolic compounds manage the chemical transfer of ubiquitin onto proteins. His findings may open new avenues for developing drugs that enhance protein interactions. In addition, Zheng analyzes cell membrane proteins to discover potential drug-binding sites. Zheng is a Howard Hughes Medical Institute investigator and his projects are also supported by the National Institutes of Health, the Pew Scholar Program, the National Science Foundation and the Burroughs Wellcome Fund. He earned his doctorate at the University of Texas Southwestern Medical Center at Dallas and has been at the 91Ě˝»¨since 2002.

, a 91Ě˝»¨professor of atmospheric sciences, was recognized for his work on climate variability. Battisti earned his doctorate in atmospheric sciences at the 91Ě˝»¨in 1988, then went to the University of Wisconsin before returning to the 91Ě˝»¨as a faculty member in 1990.

Battisti’s research looks at how interactions between the ocean, air, land and sea ice can affect the climate on timescales from seasons to decades. His more recent research has looked at how climate change is likely to affect global food production. Battisti directed the UW-based from 1997 to 2003, and co-chaired the science steering committee for the U.S. program from 1998 to 2002. He is a fellow of the American Meteorological Society and has twice received distinguished teaching awards.

, a 91Ě˝»¨professor of atmospheric sciences, was elected for his work on atmospheric radiation and climate change. Fu earned his doctorate at the University of Utah in 1991 and was on the faculty at Canada’s Dalhousie University before joining the 91Ě˝»¨in 2000.

Fu’s research concerns how the atmosphere and clouds interact with sunlight, and how satellites measure Earth variables. His work on tropospheric temperature trends from satellite observations established in the atmosphere and at Earth’s surface. He also discovered a shift toward the poles of subtropical jets in a warming climate, indicating a widening of the tropics. Fu is a fellow of the American Meteorological Society and holds an affiliate faculty position at China’s Lanzhou University.

Also elected this year was , a 91Ě˝»¨affiliate professor of oceanography and scientist at the National Oceanic and Atmospheric Administration in Seattle. His research concerns ocean circulation near the equator, the frequency of extreme El Niños under greenhouse warming, and the connection between winds and climate change.

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