Global Warming

1. Global Warming how global warming works how global warming works Green House Gases

2. Green house gases • Many greenhouse gases occur naturally in the atmosphere, such as water vapor (36-70%), Carbon dioxide (9-26%), Methane ( 4-9%) and nitrous oxide, while others are synthetic. • Those that are man-made (lower end) include the Chlorofluorocarbons (CFCs), Hydrofluorocarbons (HFCs), Perfluorocarbons (PFCs), Sulfur hexafluoride (SF6).

3. Water Vapour • Water Vapor is the most abundant greenhouse gas in the atmosphere. • Although the media gives impression that (CO2) is "the big one". water vapor is actually the dominant greenhouse gas in Earth's atmosphere. • As the temperature of the atmosphere rises, more water is evaporated from ground storage (rivers, oceans, reservoirs, soil. • Water, in gaseous form (as water vapor) and in liquid form (as tiny droplets in clouds), generates somewhere between 66% and 85% of the greenhouse effect

4. …..Water Vapour • Water vapor generates more greenhouse effect on our planet than does any other single gas. • As water vapor increases in the atmosphere, it eventually also condense into clouds, which are more able to reflect incoming solar radiation (thus allowing less energy to reach the Earth's surface and heat it up) ( Refer Water cycle).

5. Water cycle

6. Carbon dioxide (CO2) • CO2 is a green gas next to water vapour & it helps trap heat coming from the Sun in our atmosphere through the green house effect. • Carbon dioxide occur naturally in the atmosphere, through our interference with the carbon cycle (through burning forest lands, or mining and burning coal). • We artificially move carbon from solid storage to its gaseous state, thereby increasing atmospheric concentrations.

7. ….Carbon dioxide (CO2) • Carbon dioxide traps heat in the atmosphere. • Without it and other greenhouse gases, Earth would be a frozen world. • Humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago.

8. …Carbon Dioxide ( CO2) • Concentrations of carbon dioxide in the atmosphere are naturally regulated by numerous processes collectively known as the “carbon cycle” ( Ref Carbon cycle): • We breath in O2 and give out CO2 • When humans burn fossil fuels to power factories, power plants, cars and trucks, most of the carbon quickly enters the atmosphere as carbon dioxide ( five and a half billion tons of carbon each year).

9. ….CO2 • Natural fires like forest fires make carbon dioxide. • Things that humans burn make CO2. • The smoke stacks of factories that burn coal give off carbon dioxide. • The engines of cars, trucks, and buses also pump carbon dioxide into the air. • Vehicles give off another gas, carbon monoxide, which combines with O2 and form CO2

10. …Carbon cycle

11. Nitrous oxide • Nitrous oxide (N2O) is produced by both natural and human-related sources. • Primary human-related sources of N2O are agricultural soil management, animal manure management, sewage treatment, mobile and stationary combustion of fossil fuel,, and nitric acid production. • Nitrous oxide is also produced naturally from a wide variety of biological sources in soil and water, particularly microbial action in wet tropical forests ( Ref. nitrogen cycle).

12. …Nitrogen Cycle

13. Other Green Gas- Methane • When most people think of climate change they envision billowing smokestacks, and diesel engines responsible for releasing carbon dioxide into the atmosphere. • We over looking a far more inconspicuous culprit – methane– emissions of which may be slowing down.

14. Methane manufacturers. [CREDIT: USDA ARIS INFORMATION STAFF

15. ….Other Green Gas- Methane • The Earth's crust contains huge amounts of methane. • It is a chemical compound with the molecular formula CH4. • It is a relatively potent greenhouse gas with a high global warming potential. • Burning methane in the presence of oxygen produces carbon dioxide and water.

16. ….Other Green Gas -Methane • Methane is the second most abundant greenhouse gas, behind only carbon dioxide, according to the new report from the United Nations’ Intergovernmental Panel on Climate Change. • Most natural methane comes from bacteria that live in wetlands and marshes, which multiply quickly in wet or warm seasons. • Large amounts of methane are produced anaerobically

17. ….Other green House gases Haloalkanes: • Consisting of alkanes, such as methane or ethane, with one or more halogens linked, such as chlorine or fluorine • Used as flame retardants, fire extinguishants, refrigerants, propellants and solvents they have or had wide use Chlorofluorocarbons (CFC): • Contains Chlorine • Gases such as CFC’s had damaged the ozone layer, creating a huge hole through which dangerous ultraviolet light could penetrate. • .

18. Hence, it is forbidden to release CFC gasses into the atmosphere, so all redundant refrigeration plant, including air-conditioning and domestice fridges and freezers must be properly decommissioned and drained of their CFC gasses by a trained and certified technician. Hydrofluorocarbons (HFCs): • contain no chlorine. They are composed entirely of carbon, hydrogen, and fluorine. • They have no known effects at all on the ozone layer. • Only compounds containing chlorine and bromine are thought to harm the ozone layer.

19. Green House Gas in the atmosphere

20. References • http://lwf.ncdc.noaa.gov/oa/climate/gases.html#INTRO • http://www.eia.doe.gov/bookshelf/brochures/greenhouse/Chapter1.htm • http://www.solarnavigator.net/greenhouse_gases.htm • http://www.neuse.ncsu.edu/nitrogen/ • http://www.epa.gov/nitrousoxide/sources.html • http://www.umich.edu/~gs265/society/greenhouse.htm

21. http://scienceline.org/2007/03/23/env_knight_ipcccows/ • http://da.wikipedia.org/wiki/CFC-gas