Margaret A. Tolbert is an American atmospheric chemist, specializing in polar stratospheric clouds.
Margaret Tolbert grew up in Boulder, Colorado. [1] She is the daughter of Bert Mills Tolbert, a chemistry professor at University of Colorado Boulder, and sister of Elizabeth Tolbert, Caroline Tolbert, and Sarah Tolbert. [2]
Tolbert received a bachelor degree from Grinnell College in 1979 and a master degree in chemistry from University of California in 1985. [3] [4] She received a PhD in chemistry from University of Colorado Boulder in 1986, under the direction of Jesse L. Beauchamp. [5] She completed post-doctoral research at Stanford Research Institute under the direction of David M. Golden. [6] [7]
Tolbert conducted research at Stanford Research Institute before joining the faculty of University of Colorado Boulder in 1991, teaching environmental chemistry courses to nonscience majors from 1992 to 2006. [8] She was awarded Distinguished Professor in 2010. [4] She is a Fellow and Associate Director of the Cooperative Institute for Research in Environmental Sciences, a joint venture between University of Colorado Boulder and National Oceanic and Atmospheric Administration. [9]
Her research focuses on study of atmospheric chemistry, in particular polar stratospheric clouds [10] [11] [12] [13] [14] [15] and planetary atmospheres. [16] [17] [18] She co-authored the book "Stratospheric Ozone Depletion" with Ann M. Middlebrook. [19] She was featured in the book "I Want to be an Environmentalist". [20]
The sulfate or sulphate ion is a polyatomic anion with the empirical formula SO2−4. Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many are prepared from that acid.
Global dimming is a decline in the amount of sunlight reaching the Earth's surface, a measure also known as global direct solar irradiance. It was observed soon after the first systematic measurements of solar irradiance began in the 1950s, and this weakening of visible sunlight proceeded at the rate of 4–5% per decade until 1980s. Yet, solar activity did not vary more than the usual during this period. Instead, global dimming was due to an increase in atmospheric particulate matter, predominantly sulfate aerosols, as the result of rapidly growing air pollution due to post-war industrialization. Since the 1980s, a decrease in air pollution has led to a partial reversal of the dimming trend, sometimes referred to as global brightening. The reversal of dimming is not complete and varies worldwide. Brightening in developed countries during the 1980s and 1990s was offset by increased dimming in developing countries and by the expansion of the global shipping industry. During 2010s, air pollution mitigation in developing countries has also improved rapidly.
Cloud condensation nuclei (CCNs), also known as cloud seeds, are small particles typically 0.2 µm, or one hundredth the size of a cloud droplet. CCNs are a unique subset of aerosols in the atmosphere on which water vapour condenses. This can affect the radiative properties of clouds and the overall atmosphere. Water vapour requires a non-gaseous surface to make the transition to a liquid; this process is called condensation.
Melissa G. Trainer is an American astrobiologist who in 2004 demonstrated empirically that life could have formed on Earth through the interaction of methane, carbon dioxide and ultraviolet light (sunlight). She is Assistant Chief for Science, Operations, and Strategic Planning in the Planetary Environments Laboratory at NASA's Goddard Space Flight Center.
Marine cloud brightening also known as marine cloud seeding and marine cloud engineering is a proposed solar radiation management climate engineering technique that would make clouds brighter, reflecting a small fraction of incoming sunlight back into space in order to offset anthropogenic global warming. Along with stratospheric aerosol injection, it is one of the two solar radiation management methods that may most feasibly have a substantial climate impact. The intention is that increasing the Earth's albedo, in combination with greenhouse gas emissions reduction, carbon dioxide removal, and adaptation, would reduce climate change and its risks to people and the environment. If implemented, the cooling effect is expected to be felt rapidly and to be reversible on fairly short time scales. However, technical barriers remain to large-scale marine cloud brightening. There are also risks with such modification of complex climate systems.
Stratospheric aerosol injection is a proposed method of solar geoengineering to reduce global warming. This would introduce aerosols into the stratosphere to create a cooling effect via global dimming and increased albedo, which occurs naturally from volcanic winter. It appears that stratospheric aerosol injection, at a moderate intensity, could counter most changes to temperature and precipitation, take effect rapidly, have low direct implementation costs, and be reversible in its direct climatic effects. The Intergovernmental Panel on Climate Change concludes that it "is the most-researched [solar geoengineering] methodagreement that it could limit warming to below 1.5 °C (2.7 °F)." However, like other solar geoengineering approaches, stratospheric aerosol injection would do so imperfectly and other effects are possible, particularly if used in a suboptimal manner.
Owen Brian Toon is an American professor of atmospheric and oceanic sciences. He is a fellow at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado Boulder. He received an A.B. in physics at the University of California, Berkeley in 1969 and a Ph.D. in physics at Cornell University in 1975 under Carl Sagan. His research interests are in cloud physics, atmospheric chemistry, and radiative transfer. He also works on comparing Earth and other planets such as Venus.
Veronica Vaida is a Romanian-American chemist and professor at the University of Colorado Boulder. She is an expert in environmental chemistry and aerosols.
Darin W. Toohey is an American atmospheric scientist. He is a professor of atmospheric and oceanic sciences and of environmental studies at the University of Colorado Boulder since 1999. Toohey's research addresses the role of trace gases and aerosols on Earth's climate, atmospheric oxidation, and air quality. He was a Jefferson Science Fellow at the United States Department of State, 2011-2012.
Robert Jay Charlson was an American atmospheric scientist, climate scientist, pioneer in the fields of climate forcing and climate change, and coauthor of the CLAW hypothesis.Charlson is known for his research in atmospheric chemistry, aerosol physics, aerosol/cloud/climate interaction, aerosol and cloud instrumentation.
Sarah Hörst is an associate professor of planetary sciences at Johns Hopkins University, who focuses on understanding planetary atmospheric hazes, in particular the atmosphere of Saturn's moon Titan.
Anne Mee Thompson is an American scientist, who specializes in atmospheric chemistry and climate change. Her work focuses on how human activities have changed the chemistry of the atmosphere, climate forcing, and the Earth's oxidizing capacity. Thompson is an elected fellow of the American Meteorological Society, American Geophysical Union, and AAAS.
Sonia Maria Kreidenweis is an American Professor of Atmospheric Sciences at Colorado State University. Her research considers aerosols and their impact on weather and the climate. She has previously served as President of the American Association for Aerosol Research and was a board member of the American Meteorological Society. She was elected a Fellow of the American Geophysical Union in 2019.
M. Joan Alexander is an atmospheric scientist known for her research on gravity waves and their role in atmospheric circulation.
Julia Yvonne Schmale is a German environmental scientist. She is a specialist in the micro-physical makeup of the atmosphere, in particular aerosols and their interaction with clouds. She is a professor at EPFL and the head of the Extreme Environments Research Laboratory (EERL). She is a participant in the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expeditions.
Cora Einterz Randall is an atmospheric scientist known for her research on particles in the atmosphere, particularly in polar regions.
Joyce Penner is an atmospheric scientist known for her research on climate change, especially on the impact of aerosols and clouds.
John W. Birks is an American atmospheric chemist and entrepreneur who is best known for co-discovery with Paul Crutzen of the potential atmospheric effects of nuclear war known as nuclear winter. His most recent awards include the 2019 Haagen-Smit Clean Air Award for his contributions to atmospheric chemistry and the 2022 Future of Life Award for discovery of the nuclear winter effect.
Delphine Farmer is a Canadian chemist who is a professor at the Colorado State University. Her research considers the development of scientific instruments for atmospheric science. She was awarded the American Geophysical Union Atmospheric Sciences Ascent Award in 2022.
Georgiy L. Stenchikov is an applied mathematician and climate scientist focusing on studies of physical processes that govern the Earth's climate. He is a professor in the Department of Earth Science and Engineering at the King Abdullah University of Science and Technology in Saudi Arabia.