Featured Research

from universities, journals, and other organizations

Brighter Model For Global Warming: Some Pollutants Actually Slow Warming

Date:
March 25, 2005
Source:
Harvard University
Summary:
Environmental chemist Scot Martin has made surprising findings on the effect of the particles responsible for acid rain on the amount of solar energy reaching the Earth's surface. If his research is correct, ammonium sulfate particles in the atmosphere act as tiny mirrors, reflecting sunlight back into space.

To environmental chemist Scot Martin, chemistry is a way of understanding the Earth and some of its most pressing problems.

Related Articles


From global warming to heavy metal pollution in groundwater, Martin, named Gordon McKay Professor of Environmental Chemistry last July, is using the tools of chemistry to shed light on how natural processes interact with human activities to affect the environment.

Martin has already made surprising findings on the effect of the particles responsible for acid rain on the amount of solar energy reaching the Earth's surface. If his research is correct, ammonium sulfate particles in the atmosphere act as tiny mirrors, reflecting sunlight back into space. This factor, unaccounted for in most models of global warming, can cut the amount of solar energy reaching the earth's surface by as much as 25 percent, Martin said.

This finding has important implications as nations seek ways to curb human-caused global warming. Martin has forwarded his findings on to the Intergovernmental Panel on Climate Change, the multinational body created in 1988 by the World Meteorological Organization and United Nations Environment Programme to study the problem.

"Greenhouse gases are important and fairly well understood. They lead to warming, but there's also cooling," Martin said.

The creation of ammonium sulfate in the atmosphere is a complex process, beginning with the release of sulfur in pollution such as that from coal-burning power plants. Ammonia is released in agricultural activities through the use of fertilizers and in animal waste.

Together in the atmosphere, the two form ammonium sulfate, which in dry air forms small crystals but in humid air can dissolve into water droplets, greatly increasing the particle's surface area and its reflectivity.

Martin said one of the exciting aspects of being at Harvard is the potential for interactions with other faculty. In this case, Martin collaborated with Daniel Jacob, Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering in the Division of Engineering and Applied Sciences. They plugged Martin's results into Jacob's atmospheric models to see their potential effects. The findings raised new questions that Martin was able to take back to the lab to explore.

Martin has several other research projects under way as well, investigating topics as diverse as the effects of iron and manganese oxides on the fate and transport of heavy metal pollutants such as arsenic and chromium in groundwater to a collaborative effort with Cynthia Friend, Theodore William Richards Professor of Chemistry and Professor of Materials Science and associate dean of the Faculty of Arts and Sciences, and Heinrich Holland, Harry C. Dudley Research Professor of Economic Geology, to probe the chemical origins of life in the universe.

In his heavy metal work, Martin is examining how the elements iron and manganese, naturally present in the soil, affect the movement of heavy metal pollutants such as arsenic, cobalt, and chromium.

Under certain conditions, Martin said, iron and manganese oxides bind the metals and take a solid form. While the heavy metals are in that form, bound up with iron, they stay put.

But changing conditions, such as the change of seasons, causes the iron to change form, dissolving the oxide and releasing the pollutants back into the groundwater, into lake water, and into sediments.

Martin's newest work focuses on how the presence of cobalt changes the way the manganese compounds grow on surfaces such as soil particles as they solidify.

Martin came to Harvard from the University of North Carolina, Chapel Hill, in 2000 as an associate professor of environmental chemistry in the Division of Engineering and Applied Sciences. He had been an assistant professor of aquatic and atmospheric chemistry at North Carolina and before that had been a postdoctoral fellow in atmospheric chemistry at the Massachusetts Institute of Technology.

"When Scot Martin joined the Division more than five years ago, we had high expectations of his serving as a bridge between Environmental Science and Environmental Engineering," said Division of Engineering and Applied Sciences Dean Venkatesh Narayanamurti. "His research involves both atmospheric and aquatic chemistry and has brought fresh insight into an important area. Educationally, he has been a key player in teaching a broad-based environmental engineering sciences course. I am delighted that he recently got tenure. He is a stellar addition to the faculty."

Martin, who grew up in Indianapolis, said he developed a love of chemistry in high school, thanks to an enthusiastic chemistry teacher.

"I think I got on that train then and never got off," Martin said.

He received a bachelor's degree in chemistry at Georgetown University in 1991 and a doctorate in physical chemistry from the California Institute of Technology in 1995.

Martin said his high school chemistry experience made him understand the influence that a teacher - or a college professor - can have on his or her students. He said that at a place like Harvard, it's likely that future leaders, even a future president, is sitting in his class. One class he teaches, ES6, provides a broad introduction to environmental sciences and is taken by a diverse group of students, from freshmen to seniors concentrating in everything from the humanities to science. He realizes that, for some, this class may be the only one on the subject they'll take. For others, however, it may steer them toward a particular branch of science over another.

"This is my opportunity to get it right," Martin said. "With everything else I do, this may be the thing that has the most impact, depending on who's sitting in the class."


Story Source:

The above story is based on materials provided by Harvard University. Note: Materials may be edited for content and length.


Cite This Page:

Harvard University. "Brighter Model For Global Warming: Some Pollutants Actually Slow Warming." ScienceDaily. ScienceDaily, 25 March 2005. <www.sciencedaily.com/releases/2005/03/050323133619.htm>.
Harvard University. (2005, March 25). Brighter Model For Global Warming: Some Pollutants Actually Slow Warming. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2005/03/050323133619.htm
Harvard University. "Brighter Model For Global Warming: Some Pollutants Actually Slow Warming." ScienceDaily. www.sciencedaily.com/releases/2005/03/050323133619.htm (accessed October 25, 2014).

Share This



More Earth & Climate News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins