Stephen E. Schwartz

Last updated
Stephen E. Schwartz
Born
Stephen Eugene Schwartz

(1941-06-18) June 18, 1941 (age 81)
NationalityAmerican
CitizenshipUSA
Alma materA.B., Harvard; Ph.D., University of California, Berkeley
Known forCloud chemistry; atmospheric aerosols; climate forcing
Scientific career
Fields Atmospheric Chemistry, Climatology
Institutions Brookhaven National Laboratory
Doctoral advisor Harold S. Johnston
Website Home page

Stephen E. Schwartz (born June 18, 1941) is an atmospheric scientist at Brookhaven National Laboratory. He served from 2004 to 2009 as the Chief Scientist of the Atmospheric Science Program of the United States Department of Energy. He is author of over 100 scientific publications dealing mainly with cloud chemistry and forcing of climate change by atmospheric aerosols.

Contents

Education

Schwartz graduated magna cum laude from Harvard University, earned his Ph.D. from University of California, Berkeley and was a Fulbright Post-Doctoral Fellow at University of Cambridge.

Professional

He is a member of a number of professional organizations and has been elected Fellow of the American Geophysical Union, Fellow of American Association for the Advancement of Science and Fellow of International Union for Pure and Applied Chemistry. He was named ISI Highly Cited researcher in 2006.

Scientific Contributions

Acid Rain

Schwartz was a leading scientist in the area of atmospheric sulfur and acid rain. Schwartz authored "the study some credit with spurring acid rain legislation in the 1990s." [1] His paper "Acid deposition: Unraveling a regional phenomenon" Science 243, 753-763 (1989). [2] was cited by the US Department of Energy in 2017 as one of 40 "Research Milestones" in the 40-year history of the Department. The citation reads in part "Schwartz's findings gave the first clear picture of the nationwide impacts of different sulfur and nitrogen sources and led to changes to the Clean Air Act." [3]

Aerosol Forcing of Climate Change

A 1992 article [4] authored with Robert Jay Charlson, James E. Hansen, and others provided the first global-scale estimates of radiative forcing by anthropogenic sulfate aerosol. This forcing offsets a substantial but highly uncertain fraction of forcing by incremental greenhouse gases; however the aerosol is short lived in the atmosphere, about a week, compared to the decadal to centennial residence times of greenhouse gases. This paper has been highly influential, with over 3500 citations. [5] In 1995, as a result of this work, the journal Science named sulfate aerosol as one of nine runners-up for Molecule of the Year. [6]

Related Research Articles

<span class="mw-page-title-main">Attribution of recent climate change</span> Effort to scientifically ascertain mechanisms responsible for recent global warming

Efforts to scientifically ascertain and attribute mechanisms responsible for recent global warming and related climate changes on Earth have found that the main driver is elevated levels of greenhouse gases produced by human activities, with natural forces adding variability. The likely range of human-induced surface-level air warming by 2010–2019 compared to levels in 1850–1900 is 0.8 °C to 1.3 °C, with a best estimate of 1.07 °C. This is close to the observed overall warming during that time of 0.9 °C to 1.2 °C, while temperature changes during that time were likely only ±0.1 °C due to natural forcings and ±0.2 °C due to variability in the climate.

<span class="mw-page-title-main">Greenhouse effect</span> Atmospheric phenomenon causing planetary warming

The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly to space, resulting in a warmer planet. Earth's natural greenhouse effect makes life as we know it possible and carbon dioxide plays a significant role in providing for the relatively high temperature on Earth. The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond the temperature it would have in the absence of its atmosphere. Without the greenhouse effect, the Earth's average surface temperature would be about −18 °C (−0.4 °F) compared to Earth's actual average surface temperature of approximately 14 °C (57.2 °F). In addition to the naturally present greenhouse gases, human-caused increases in greenhouse gases trap greater amounts of heat, causing the Earth to become warmer over time.

<span class="mw-page-title-main">Aerosol</span> Suspension of fine solid particles or liquid droplets in air or another gas

An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of anthropogenic aerosols include particulate air pollutants, mist from the discharge at hydroelectric dams, irrigation mist, perfume from atomizers, smoke, dust, steam from a kettle, sprayed pesticides, and medical treatments for respiratory illnesses. When a person inhales the contents of a vape pen or e-cigarette, they are inhaling an anthropogenic aerosol.

<span class="mw-page-title-main">Sulfate</span> Oxyanion with a central atom of sulfur surrounded by 4 oxygen atoms

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.

<span class="mw-page-title-main">Global cooling</span> Discredited 1970s hypothesis of imminent cooling of the Earth

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<span class="mw-page-title-main">Global dimming</span> Reduction in the amount of sunlight reaching Earths surface

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<span class="mw-page-title-main">Cloud condensation nuclei</span> Small particles on which water vapor condenses

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 requires a non-gaseous surface to make the transition from a vapour to a liquid; this process is called condensation.

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The term sulfate aerosols is used for a suspension of fine solid particles of a sulfate or tiny droplets of a solution of a sulfate or of sulfuric acid (hydrogen sulfate). They are produced by chemical reactions in the atmosphere from gaseous precursors (with the exception of sea salt sulfate and gypsum dust particles). The two main sulfuric acid precursors are sulfur dioxide (SO2) from anthropogenic sources and volcanoes, and dimethyl sulfide (DMS) from biogenic sources, especially marine plankton. These aerosols can cause a cooling effect on earth.

<span class="mw-page-title-main">CLAW hypothesis</span> A hypothesised negative feedback loop connecting the marine biota and the climate

The CLAW hypothesis proposes a negative feedback loop that operates between ocean ecosystems and the Earth's climate. The hypothesis specifically proposes that particular phytoplankton that produce dimethyl sulfide are responsive to variations in climate forcing, and that these responses act to stabilise the temperature of the Earth's atmosphere. The CLAW hypothesis was originally proposed by Robert Jay Charlson, James Lovelock, Meinrat Andreae and Stephen G. Warren, and takes its acronym from the first letter of their surnames.

<span class="mw-page-title-main">Veerabhadran Ramanathan</span>

Veerabhadran "Ram" Ramanathan is Edward A. Frieman Endowed Presidential Chair in Climate Sustainability Scripps Institution of Oceanography, University of California, San Diego. He has contributed to many areas of the atmospheric and climate sciences including developments to general circulation models, atmospheric chemistry, and radiative transfer. He has been a part of major projects such as the Indian Ocean Experiment (INDOEX) and the Earth Radiation Budget Experiment (ERBE), and is known for his contributions to the areas of climate physics, Climate Change and atmospheric aerosols research. He is now the Chair of Bending the Curve: Climate Change Solutions education project of University of California. He has received numerous awards, and is a member of the US National Academy of Sciences. He has spoken about the topic of global warming, and written that "the effect of greenhouse gases on global warming is, in my opinion, the most important environmental issue facing the world today."

<span class="mw-page-title-main">Stratospheric sulfur aerosols</span>

Stratospheric sulfur aerosols are sulfur-rich particles which exist in the stratosphere region of the Earth's atmosphere. The layer of the atmosphere in which they exist is known as the Junge layer, or simply the stratospheric aerosol layer. These particles consist of a mixture of sulfuric acid and water. They are created naturally, such as by photochemical decomposition of sulfur-containing gases, e.g. carbonyl sulfide. When present in high levels, e.g. after a strong volcanic eruption such as Mount Pinatubo, they produce a cooling effect, by reflecting sunlight, and by modifying clouds as they fall out of the stratosphere. This cooling may persist for a few years before the particles fall out.

Tom Michael Lampe Wigley is a climate scientist at the University of Adelaide. He is also affiliated with the University Corporation for Atmospheric Research (UCAR). He was named a fellow of the American Association for the Advancement of Science (AAAS) for his major contributions to climate and carbon cycle modeling and to climate data analysis, and because he is "one of the world's foremost experts on climate change and one of the most highly cited scientists in the discipline." His h-index is 107, one of the highest in the discipline. He contributed to many of the reports published by the Intergovernmental Panel on Climate Change.

<span class="mw-page-title-main">Stratospheric aerosol injection</span> Putting particles in the stratosphere to reflect sunlight to limit global heating

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 eruptions. 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] method, with high agreement that it could limit warming to below 1.5°C." 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.

<span class="mw-page-title-main">Particulates</span> Microscopic solid or liquid matter suspended in the Earths atmosphere

Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The term aerosol commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation.

Meinrat O. Andreae, born in 1949 in Augsburg, is a German biogeochemist. Since 1987, he has worked as Director and Scientific Member at the Max Planck Institute for Chemistry (MPIC) in Mainz.

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.

Patricia K. Quinn is a atmospheric chemist working at the National Oceanic and Atmospheric Agency's Pacific Marine Environmental Lab. She is known for her work on the impact of atmospheric aerosol particles on air quality and climate.

Glenn Edmond Shaw is an American scientist specializing in atmospheric physics, especially relating to global climate change and long-range transport of aerosol material. He is Emeritus Professor of Physics and Atmospheric Science at the University of Alaska Fairbanks and a member of the scientific staff of the Geophysical Institute. He conducted research on global atmospheric transport of aerosols and feedback of biogenic aerosols on global climate. He and Kenneth Rahn did research on the sources and climatic effect of Arctic haze. He did pioneering work on the scientific concept of climate homeostasis through the sulfur cycle and atmospheric aerosol.

References

  1. Lawrence Solomon (September 1, 2007). "The aerosol man". National Post. Retrieved 2007-12-23.
  2. Schwartz, Stephen E. (1989). "Acid Deposition: Unraveling a Regional Phenomenon". Science. 243 (4892): 753–763. Bibcode:1989Sci...243..753S. doi:10.1126/science.243.4892.753. PMID   17820422. S2CID   17807181.
  3. "Newsroom".
  4. Charlson, R. J.; Schwartz, S. E.; Hales, J. M.; Cess, R. D.; Coakley, J. A.; Hansen, J. E.; Hofmann, D. J. (1992). "Climate Forcing by Anthropogenic Aerosols". Science. 255 (5043): 423–430. Bibcode:1992Sci...255..423C. doi:10.1126/science.255.5043.423. PMID   17842894. S2CID   26740611.
  5. "Google Scholar".
  6. Editor. (1995). Molecule of the Year: A New Form of Matter Unveiled. Science. 270: 1902.