Stephen E. Schwartz

Stephen E. Schwartz (born 1941) is an atmospheric scientist at Brookhaven National Laboratory. He has served since 2004 as the Chief Scientist of the Atmospheric Science Program of the United States Department of Energy. The program is charged with developing a comprehensive understanding of how the atmosphere processes energy related trace chemicals, such as nitrogen oxides, sulfur, aerosols and carbon dioxide. The current focus is on aerosols and carbon dioxide.

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.

cientific 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." [cite web
author = Lawrence Solomon
title = The aerosol man
publisher = National Post
url = http://www.ecd.bnl.gov/news/NationalPost.html
date = September 01, 2007
accessdate = 2007-12-23 ]

Global Warming

In 2007, Schwartz published a new estimate of climate sensitivity to rising carbon dioxide. [cite web
author = Stephen E. Schwartz
title = HEAT CAPACITY, TIME CONSTANT, AND SENSITIVITY OF EARTH'S CLIMATE SYSTEM
publisher = Brookhaven National Laboratory
url = http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf
date = September 17, 2007
accessdate = 2007-12-23 ] Schwartz estimated climate sensitivity based on the heat capacity and the time constant of the climate system. Heat capacity was estimated with ocean heat content and the time constant by perturbations and relaxations in the surface temperature record. His estimate of climate sensitivity was about one-third of the most recent estimate by the IPCC. Schwartz's estimate has been criticized by data analyst and statistician Grant Foster and climate researchers James Annan, Gavin Schmidt and Michael Mann. In their analysis, Schwartz's method produces climate lag times that are "unrealistically low in comparison to the known behaviour of the models in response to changes in GHG forcing." [http://www.jamstec.go.jp/frsgc/research/d5/jdannan/comment_on_schwartz.pdf]

Schwartz initial estimate of climate sensitivity in his 2007 paper was of an equilibrium temperature increase for doubled carbon dioxide of 1.1 ± 0.5 K. [ [http://www.ecd.bnl.gov/steve/pubs/HeatCapacity.pdf (PDF) Heat capacity, time constant, and sensitivity of Earth's climate system. Schwartz S. E. J. Geophys. Res.] ] In a revised 2008 paper Schwartz increased his estimate to 1.9 ± 1.0 K, a number "somewhat lower than the central estimate of the sensitivity given in the 2007 assessment report of the Intergovernmental Panel on Climate Change, but consistent within the uncertainties of both estimates". [ [http://www.ecd.bnl.gov/steve/pubs/HeatCapCommentResponse.pdf (PDF) Reply to comments by G. Foster et al., R. Knutti et al., and N. Scafetta on "Heat capacity, time constant, and sensitivity of Earth's climate system". Schwartz S. E. J. Geophys. Res] ]

Despite his lower estimate for sensitivity, Schwartz is still concerned about global warming. Schwartz explained his research by saying "it means that the climate is less sensitive to [carbon dioxide] than currently thought, which gives some breathing room, but a lower sensitivity does not solve the long-term problem that would result from continued buildup of [carbon dioxide] ." [cite web
author = Anna Gustafson
title = Things are heating up
publisher = The North Shore Sun
url = http://www.ecd.bnl.gov/news/NorthShoreSun.html
date = September 06, 2007
accessdate = 2007-12-23 ]

References

External links

* [http://www.ecd.bnl.gov/steve/schwartz.html Stephen E. Schwartz Home Page]
* [http://hcr3.isiknowledge.com/author.cgi?&id=5556 Highly Cited page]
* [http://www.ecd.bnl.gov/news/NationalPost.html The Aerosol Man]
* [http://www.realclimate.org/index.php/archives/2007/09/climate-insensitivity/ Real Climate: Climate Insensitivity]
* [http://julesandjames.blogspot.com/2007/09/comment-on-schwartz.html James Annan: Comment on Schwartz]