Global Dimming

Research Findings for Global Dimming

Post research findings for this topic using the formatting template on the main research page. Please add your name to your posting. As research findings accumulate, you should organize and rearrange findings to represent viewpoints and other categories of information (background, primary research, news).

Return to Main Research Page

---

Findings

Global Dimming Resources

http://www.globalissues.org/EnvIssues/GlobalWarming/globaldimming.asp

http://www.pbs.org/wgbh/nova/sun/

http://www.nasa.gov/centers/goddard/news/topstory/2007/aerosol_dimming.html

• There is also an interesting documentary titled "Horizons" that was produced by the BBC

Explanation of Global Dimming

History of Global Dimming

Adam, David. "Goodbye Sunshine." The Guardian. 18 Dec 2003. 30 Mar 2008 <http://www.guardian.co.uk/science/2003/dec/18/science.research1>.

Adam's article gives a detailed summary of who first discovered the idea of global dimming, and the different scientists that have published related research since then. Atsumu Ohmura first published research on global warming in 1985, when he recorded that since the 1960's, the amount of sunshine penetrating Europe had declined by 10%. Since Ohmura's article was published, several other research papers were published during the 1990s on global dimming. All of these papers provided additional evidence to support Ohmura's theory. It was reported that sunshine in Ireland was decreasing, both the Arctic and the Antarctic were getting darker and that light in Japan was also decreasing. The most surprising evidence was that levels of solar radiation in the former Soviet Union had gone down almost 20% between 1960 and 1987. Since then, many more scientists have begun their own research around the world, and are continuing to find evidence that supports Ohmura's original claim.

Geneva Granatstein

Explanation of Dimming

Appell, David. "The Darkening Earth." Scientific American. August 2004,p16-18. <http://web.ebscohost.com/bsi/detail?vid=3&hid=116&sid=f8bc64c8-2fca-460f-8a3c-203ad833101b%40sessionmgr107>

Gives a good background behind global dimming. Makes the claim that the amount of solar reduction has been about 2.7% per decade since the 1950s. Aerosols and other particulates/greenhouse gases are the main culprits behind the dimming and lead to more cloud formation which deflects more solar energy each year. This could affect rainfall and farming productivity among other things. This is a news-based article, the author is reporting the facts put forth from the scientific community.

Andrew Kersh

A Rather Scientific Explanation

Chapman, David M. "Global Warming: Are we hiding behind a smokescreen?" Geodate. May 2006, p6-8.<http://web.ebscohost.com/ehost/pdf?vid=5&hid=102&sid=d4808179-702e-4ac4-b52f-4833a9fadf4e%40sessionmgr109>

This article has some interesting tables and discussion of increasing cloud levels around the world, and lots of specific numbers to back up the argument. This is a good source to use for some concrete statistical information.

Andrew Kersh

A Super Scientific Explanation

Kvalevåg, Maria M & Myhre, Gunnar."Human Impact on Direct and Diffuse Solar Radiation during the Industrial Era". Journal of Climate. Oct 2007.p. 4874. <http://proquest.umi.com/pqdweb?index=0&did=1365218991&SrchMode=1&sid=1&Fmt=3&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1207507405&clientId=10553>

I am not sure if this is of any use to us, but it has some really advanced rhetoric on global dimming and warming. Lots of results of studies as well. It is similar to the above article, but this one is from an academic journal so I believe it to be peer-reviewed and quite reliable.

Andrew Kersh

What is Global Dimming?

"Global Dimming" Climate Change and Global Warming. 15 Janurary 2005. 31 March 2008 <http://www.globalissues.org/EnvIssues/GlobalWarming/globaldimming.asp#Whatisglobaldimming>

This article explains how Global Dimming is the reduction of heat reaching the earth. Fossil fuel use, as well as producing greenhouse gases, creates other by-products. These by-products are also pollutants, such as sulphur dioxide, soot, and ash. These pollutants however, also change the properties of clouds.

Clouds are formed when water droplets are seeded by air-borne particles, such as pollen. Polluted air results in clouds with larger number of droplets than unpolluted clouds. This then makes those clouds more reflective. More of the sun’s heat and energy is therefore reflected back into space.

Molly Stephens

Over View of History and Research

Sington, David. “Why the Sun Seems to be ‘Dimming’?” BBC News. Jan 2005. [1]

This article goes over the cloud cover changes that have occurred in the past fifty years. It focuses on the scientists and their research on the subject. It also addresses the idea that global dimming is actually hiding the effects of global warming.

This article is very useful learn about the basics of global warming and a little bit about the research involved

Amanda Arrigotti

Cause and Effect

Sunshine Levels Diminishing

Chang, Kenneth. "Globe Grows Darker as Sunshine Diminishes 10% to 37%." Common Dreams Newscenter. 13 May 2004. Common Dreams. 30 Mar 2008 <http://commondreams.org/headlines04/0513-01.htm>.

Chang's article was written in 2004 for the New York Times. It addresses the idea that the amount of sunshine reaching earth has diminished anywhere from 10% to 37% in the 20th century. The article's main point is to make the reader aware that many scientists have been studying the dimming phenomenon, and that they are compiling more and more evidence that supports the theory of global dimming. There is also explanation included of how these scientists perform their studies. The article completely supports the scientist's findings and is not an argument for or against global dimming.

Geneva Granatstein

Pollutants in the Weather

“Air Pollution”. National Geographic. 22 April 2008. <http://science.nationalgeographic.com/science/environment/environmental-threats/pollution-overview.html>.

This national geographic section on air pollution gives some insight into what certain particles effect Global Dimming issues. This information demonstrates what is induced by humans and what occurs naturally. Information about Global Warming is also provided and helps make for an easy comparision between the two issues.

Alberto Fazio

News on Less Rainfall

Tobin, Mary. "Could Global Warming Mean Less Sunshine and Less Rainfall?." Earth Observatory. 20 05 2004. NASA. 4 Apr 2008 <http://earthobservatory.nasa.gov/Newsroom/MediaAlerts/2004/2004052017017.html>.

This article from the NASA Observatory explains in more detail exactly how global dimming is causing the temperatures to change. The clouds produced by man-made pollutants are much more dense and the water residence time has increased because a warmer atmosphere can hold more water. This reduces the amount of rain.

Beth Kirpes

General Dimming Info

Lovett, Richard A. "A Dim Outlook." Weatherwise. Sept/Oct 2004, p17. <http://proquest.umi.com/pqdweb?did=733701731&sid=1&Fmt=4&clientId=10553&RQT=309&VName=PQD>

The most interesting issue this raises is the fact that because of dimming the earth may actually get warmer and drier instead of warmer and wetter. It was thought that global warming would make more rain fall because of increased humidity, but dimming causes slower evaporation of water and the air cannot become humid so easily. This article agrees with the previous one as far as diminishing overall sunlight in the world. It finally mentions a possible link between the dimming effect and reduced monsoon seasons in India. This article is much like the previous one because the author is writing based off of what scientists have to say on the issue.

Andrew Kersh

History of the Effects

"Global Dimming?." RealClimate. 18 Jan 2005. 30 Mar 2008 <http://www.realclimate.org/index.php?p=105>.

This resource is written in a blog form, where one person posted the topic and information they had gathered and then people had the opportunity to post their own opinions as well as additional research. The information originally posted shows the two sides to the topic. Some people are against the idea of global warming, while others are adamant in believing it, so it was very interesting to read their different reasoning. The page brings up the idea that as of yet there is no actual solid explanation for the phenomenon, but brings up many potential answers and theories that are being researched. The page also discusses the possible connection between global dimming and the famines in Ethiopia in the 1980's.

Geneva Granatstein

Discoveries in Global Dimming

"Dimming the Sun" NOVA Science and Programming. 31 March 2008 <http://www.pbs.org/wgbh/nova/sun/dimming.html>

This article was written to summarize the discoveries of global dimming in the 21st century. Air pollution is significantly reducing the amount of sun light that’s hitting the earth, lowers temperatures and hides the warming effects of greenhouse gases. The article sends you to a link of a slide show that shows how global dimming has progressed since the 1800's

Molly Stephens

Effects of Global Dimming

Hayes , Brian J. "Global Dimming: BBC TWO's Horizon series broadcast of 13 January 2005." Transmitting the Wisdom of Ages. 10 2002. Age-of-the-Sage. 6 Apr 2008 <http://www.age-of-the-sage.org/global_dimming.html>.

This article was written in response to the BBC series broadcast, Horizons. This article focuses on the effects of global dimming while also explaining how it works. Some climatologists say that global dimming is helping to cause global warming. Global dimming is caused by tiny particles of soot, ash, and sulphur dioxide that are airborne and absorb tiny particles of rain while then form clouds and reflect the sun's heat back to space. This article suggests that global dimming causes a major change in the climate which accounts for the famine in Ethiopia and the lack of seasonal rains in Sub-Saharan Africa due to altered rainfall patterns. Offers a solution to the problem which is to clean up particle emissions, however, it also states that as global dimming becomes less of an issue that global warming will get much worse because global dimming is masking the intensity of the change in temperatures. It gives examples of places with cleaner air being much hotter.

Beth Kirpes

Proposed Solutions

Prominent Scientist Suggests Increasing Dimming!

Monbiet, George. "Shortcut to Catastrophe." AlterNet.com. April 14, 2008.<http://www.alternet.org/environment/41025?page=1>.

I realize this is kind of a counter-solution but it is interesting and definitely worth our time to look at and evaluate for usefulness. Basically a Nobel prize winning chemist wants to pump 5 million pounds of sulphur into the atmosphere in an effort to increase dimming and hopefully scare back global warming by deflecting even more of the sun's rays. This is hugely controversial and crazy but it deserves to be included here, however convoluted.

Andrew Kersh

How to Combat

“How to Combat Global Warming and Global Dimming” How to Combat. 22 April 2008. <http://www.xiportal.com/stealmysunshine/?tabid=359&tabindex=17>

This article offers some explanations and solutions regarding the effects of Global Dimming and Global Warming. This article adds an interesting insight into how the two issues may potentially be dependant on each other. A theory is proposed that with out one the other could grow out of control.

Alberto Fazio

Can Global Dimming be Reduced?

"Global Dimming Part 1." ScienceBlog.org. April 14, 2008.<http://www.scienceblog.org/community/modules.php?op=modload&name=News&file=article&sid=111>.

Has a solid section on possible solutions to reduce the dimming effect about 2/3rds of the way down the page. Kind of frustrating because it talks opaquely about the problem, not enough facts to back up the abstractions. It also has some good links to other dimming resources, some of which we already have posted on the wiki. This is a blog, but it seems very scientific and reliable, I would consider this quality information.

Andrew Kersh

A dim outlook

http://www.bbc.co.uk/sn/tvradio/programmes/horizon/dimming_trans.shtml

This is a transcript from the BBC's movie titled "Horizons" which was one of the main ways people were introduced to the concept of global dimming. This movie brings up potential solutions, but gives a bit of a depressing outlook on it, basically saying that no matter how hard we try to eliminate pollution particles, it's not going to make a difference. These experts have the view that there is currently no sure solution to the problem.

Geneva Granatstein

Global Warming/Controversies

One Interesting Outlook

"What is Global Dimming?" UnlimitedWatts.com. <http://unlimitedwatts.com/listpage.jsp?page=globaldimming>. 30 March 2008.

This is included because of the view it presents in the fourth paragraph. It has some good statements regarding reverting global dimming, and intentional global dimming. This information seemed unique enough to call attention to. I believe this article was written more recently than the previous two, the view seems very liberal and advocates use of "alternative energies and conscientious living" to help offset global warming and dimming. Unlike the other articles, this one gives an opinion on how to stop dimming, whereas the more scientific based ones simply put the facts out there for us to take however we want. This article's purpose is to motivate people to live cleaner to help fix our earth.

Andrew Kersh

An Interesting connection

Lyon, Rob. "Global Warming: The Arctic is Melting." The Defence of Marxism. 18 Aug 2005. 15 Apr 2008 <http://www.marxist.com/global-warming-arctic180805.htm>.

This article has a paragraph on the connection between global dimming and warming, explaining that it is thought that global warming was calmed until the 1990's thanks to global dimming. It also brings up that our attempts to solve global warming may actually be contributing to global warming and may even be speeding the process up.

Geneva Granatstein

The Pro-Global Dimming Approach

Crutzen, Paul. "Albedo Enhancement by Stratospheric Sulfur Injections: A Contribution to Resolve a Policy Dilemma?." Climatic Change 77.3-4.1 Aug 2006 211-120. 16 Apr 2008

This is an essay by a Nobel Laureate that argues that we should use Global Dimming to fight Global Warming by shooting sulphur into the startosphere. He argues that while it might make life for some individuals worse, but that atleast the earth will be cooled and the effects of Global Warming will not be seen. Personally I feel like this would be problematic because Global Warming would just be hidden until it would get really bad.

Gabe Olson

A Different Perspective

Spencer, Metta. "Global Dimming or Warming?." Metta Spencer's WebBlog. 16 11 2007. I Power Blogger. 2 Apr 2008 <http://metta-spencer.blogspot.com/2007/11/global-dimming-or-warming.html>.

This a link to a lady's blog so it isn't scientific or anything but she offers a new perspective on the issue that is at least worth looking at. In the beginning, she explains global dimming but then she says that this theory was disproved. That global dimming isn't real. She says that all the pollutant particles in the air aren't masking the heating effects-they are increasing the severity of it. She then tries to explain that the brown clouds full of pollutants vary in content and according to altitude, their effects as well. The water vapor has a cooling effect but the particles contradict it by reflecting light in all directions, including towards space. All the black soot particles in the air heat the atmosphere which only intensifies the heating effect of greenhouse gases.

Beth Kirpes