CHEMISTRY OF THE ENVIRONMENT (GREENHOUSE EFFECT) Part 2

[PHOTO AT LEFT - Professor Angel C. de Dios; Photo at right, with his son,

Alexander Gabriel]

TORONTO, NOVEMBER 27, 2009 - [PHNO DISCLAIMER: This lecture on 'Chemistry of the Environment' by Professor de Dios was uploaded to his website at http://bouman.chem.georgetown.edu and copied and pasted here on November 27, 2009 without permission. Photos are added also without permission from the author. Accompanying scientific photos are taken from various photo sharing Internet science, educational and military websites. All photos are appended by PHNO to enhance visual effect of the page layout and should not literally affect the originality of the article.]
 
HERE IS LECTURE PART 2:

Chemistry of the Environment (Greenhouse Effect) Lecture XXIV - Chem 002
by Dr. Angel Cagandahan de Dios, Georgetown University, Washington, DC

("The Earth system follows laws which scientists strive to understand," said Dr. F. Sherwood Rowland,
a Nobel laureate in chemistry.)


("The public deserves rational decision-making based on the best scientific advice about what is likely to happen, not what political entities might wish to happen." From: Scientists Protest Bush's Misuse of Science | Science Blog)

The following is based on course materials developed and compiled by Arthur Glasfeld and Margret Geselbracht of the Department of Chemistry at Reed College. Materials have been specifically drawn (with permission from the authors) from the following document: Introduction to the Greenhouse Effect

Molecular rotations and vibrations
(Pls. click the hyperlinked text)


Simulations are from http://www.ems.psu.edu/~bannon/moledyn.html

Nitrogen

Oxygen

Molecular vibrations

Water

Carbon dioxide

Ozone

Infrared absorption and gas pressure

http://www.wwnorton.com/college/chemistry/chemconnections/Warming/moviepages/IRconc.htm

Infrared spectra of greenhouse gases

http://www.wwnorton.com/college/chemistry/chemconnections/Warming/moviepages/greenIR.htm

Changes in greeenhouse gas concentration in the earth's atmosphere

http://www.wwnorton.com/college/chemistry/chemconnections/Warming/pages/longterm.html

The Great Experiment on Planet Earth

http://earthguide.ucsd.edu/globalchange/global_warming/01.html  

Recent articles, news or press release

Oceans could slurp up carbon dioxide to fight global warming
19 November 2007
Environmental Science & Technology

Researchers in Massachusetts and Pennsylvania are proposing a new method for reducing global warming that involves building a series of water treatment plants that enhance the ability of the ocean to absorb carbon dioxide from the atmosphere. About 100 such plants — which essentially use the ocean as “a giant carbon dioxide collector” — could cause a 15 percent reduction in emissions over many years, they say. About 700 plants could offset all Co2 emissions. Their study is scheduled to appear in the Dec. 15 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

Scientists believe that excessive build-up of carbon dioxide in the air contributes to global warming. In addition to cutting down on carbon dioxide emissions by reducing the use of fossil fuels, researchers have focused on new technologies that remove the gas directly from the atmosphere.

In the new study, Kurt Zenz House and colleagues propose building hundreds of special water treatment facilities worldwide that would remove hydrochloric acid from the ocean by electrolysis and neutralize the acid through reactions with silicate minerals or rocks. The reaction increases the alkalinity of the ocean and its ability to absorb carbon dioxide from the atmosphere. The process is similar to the natural weathering reactions that occur among silicate rocks but works at a much faster rate, the researchers say.

“Electrochemical Acceleration of Chemical Weathering as an Energetically Feasible Approach to Mitigating Anthropogenic Climate Change”

DOWNLOAD PDF http://pubs.acs.org/cgi-bin/sample.cgi/esthag/asap/pdf/es0701816.pdf


DOWNLOAD HTML http://pubs.acs.org/cgi-bin/sample.cgi/esthag/asap/html/es0701816.html

Society for General Microbiology
10 December 2007

Nitrous oxide from ocean microbes

A large amount of the greenhouse gas nitrous oxide is produced by bacteria in the oxygen poor parts of the ocean using nitrites, Dr Mark Trimmer told journalists at a Science Media Centre press briefing today.

Dr Trimmer looked at nitrous oxide production in the Arabian Sea, which accounts for up to 18 % of global ocean emissions. He found that the gas is primarily produced by bacteria trying to make nitrogen gas.

“A third of the ‘denitrification’ that happens in the world’s oceans occurs in the Arabian Sea (an area equivalent to France and Germany combined)” said Dr Trimmer from Queen Mary, University of London. “Oxygen levels decrease as you go deeper into the sea. At around 130 metres there is what we call an oxygen minimum zone where oxygen is low or non-existent. Bacteria that produce nitrous oxide do well at this depth.”

Gas produced at this depth could escape to the atmosphere. Nitrous oxide is a powerful greenhouse gas some 300 times more so than carbon dioxide, it also attacks the ozone layer and causes acid rain.

“Recent reports suggest increased export of organic material from the surface layers of the ocean under increased atmospheric carbon dioxide levels. This could cause an expansion of the oxygen minimum zones of the world triggering ever greater emissions of nitrous oxide.”

Society for General Microbiology
10 December 2007

Greenhouse gas from English streams

English chalk streams are less healthy than we thought and are potentially even contributing to global warming, said Dr Mark Trimmer at a Science Media Centre press briefing today.

Dr Trimmer looked at a plant that covers up to three quarters of the surface of some streams and found that it helps methane generated in the sediment beneath the plants to escape into the atmosphere. “We found similar emissions to some UK peat bogs” said Dr Trimmer from Queen Mary, University of London. “This changes our perception of the health of the ecosystem and it indicates another disadvantage of agriculture.”

Over 90% of the methane emissions from the river Frome in Dorset that reach the atmosphere do so via the stems of water crowfoot. The plant also causes a build-up of sediment from neighbouring farmland, which aids the production of methane by bacteria in the stream.

“Chalk streams are a British specialty habitat and a priority under the UK’s Biodiversity Action Plan. They have a high status but there is growing concern about their ecological decline.”

Dr Trimmer estimates that the total area of chalk streams in the UK is around 20 km2. The situation he observed in Dorset is likely to be widespread. More research is needed to understand methane emissions from chalk streams fully. “There is obvious climatic concern for any unquantified potential source of methane.”

Society for General Microbiology
10 December 2007

Methane from microbes: a fuel for the future
(Photo at right: Sediment samples from methane cold
seeps off California sea: from insciences.org)

Microbes could provide a clean, renewable energy source and use up carbon dioxide in the process, suggested Dr James Chong at a Science Media Centre press briefing today.

“Methanogens are microbes called archaea that are similar to bacteria. They are responsible for the vast majority of methane produced on earth by living things” says Dr Chong from York University. “They use carbon dioxide to make methane, the major flammable component of natural gas. So methanogens could be used to make a renewable, carbon neutral gas substitute.”

Methanogens produce about one billion tonnes of methane every year. They thrive in oxygen-free environments like the guts of cows and sheep, humans and even termites. They live in swamps, bogs and lakes. “Increased human activity causes methane emissions to rise because methanogens grow well in rice paddies, sewage processing plants and landfill sites, which are all made by humans.”

Methanogens could feed on waste from farms, food and even our homes to make biogas. This is done in Europe, but very little in the UK. The government is now looking at microbes as a source of fuel and as a way to tackle food waste in particular.

Methane is a greenhouse gas that is 23 times more effective at trapping heat than carbon dioxide. “By using methane produced by bacteria as a fuel source, we can reduce the amount released into the atmosphere and use up some carbon dioxide in the process!”

Society for General Microbiology
10 December 2007

Food source threatened by carbon dioxide

Carbon dioxide increasing in the atmosphere may affect the microbial life in the sea, which could have an impact on a major food source, warned Dr Ian Joint at a Science Media Centre press briefing today.

Dr Joint is sequencing the DNA of different ocean bacteria to find out how they will respond to an increase in carbon dioxide. “So far from one experiment we have sequenced 300 million bases of DNA, about one tenth the size of the human genome. We are analyzing this ‘ocean genome’ to see if changes might affect the productivity of the sea.”

Worldwide, fish from the sea provide nearly a fifth of the animal protein eaten by man. If microscopic plants that fish eat are affected by carbon dioxide, this may deplete a major food source.

“Bacteria still control the world” said Dr Joint from Plymouth Marine Laboratory. “They ensure that the planet is fertile and that toxic materials do not accumulate.” The carbon dioxide produced by humans is turning the oceans into weak acids. This century, the seas will be more acidic than they have been for 20 million years.

“There are many millions of different bacteria in the ocean. They control the cycling of oxygen, carbon, nitrogen and sulphur; microbes in the sea generate half of the oxygen produced globally every year.” So the atmosphere could also be affected by ocean acidification. “Bacteria made the earth suitable for animals by producing oxygen nearly 2 billion years ago. We want to find out if human activities will have a major impact on microbial life in the seas and if this is likely to be a problem for mankind in the future”

More News on Global Warming and Greenhouse Gases

http://www.paete.org/forums/viewtopic.php?t=748

http://www.paete.org/forums/viewtopic.php?t=962


Contact Info: Dr. Angel C. de Dios
Department of Chemistry
Georgetown University
Washington, DC 20057
Office: 602 C Reiss Science Building
Phone: (202) 687-0670
Email: dediosa@georgetown.edu


Chief News Editor: Sol Jose Vanzi

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