Greenhouse Effect and Precautionary Principle

Arctic EcosystemsObjective 5.2

5.2.3 Naturally Occurring GH Gases

• Water vapor H20• Carbon dioxide CO2• Methane CH4• Nitrous Oxide N2O• Ozone O3

Anthropogenic GH Gases

• Chlorofluorocarbons (CFC)• Hydrochlorofluorocarbons (HCFC)• Bromofluorocarbons (Halons)

Not all equally potent heat trappers

• Methane is 21X better at trapping heat than CO2

• N2O is 310X better at trapping heat than CO2

Trending

• In 2010, total U.S. greenhouse gas emissions were 6,865.5 Tg or million metric tons CO2 Eq

• Total U.S. emissions have increased by 11.0 percent from 1990 to 2010

• Since 1990, U.S. emissions have increased at an average annual rate of 0.5 percent

2009 to 2010 3.3% increase – economic upturn and very hot summer

Mauna Loa Observatory Data

Recent Trends in CO2

One Year Of CO2

Ups and downs

What might account for the peaks and valleys in the CO2 levels throughout the year?

Location, Location, Location

Why would Mauna Loa observatory (atop a mountain on an island in the middle of the Pacific ocean) be a good place to locate your sampling station?

Not just in the tropics….

http://zebu.uoregon.edu/1998/es202/images/green35.jpg

Relative importance of gaseshttp://www.koshland-science-museum.org/exhibitgcc/images/causes02.jpg

Production of oxides of nitrogen

• Burning fossil fuels• Organic and commercial fertilizers• Industrial process such as making nitric acid

Production of methane

• Cattle ranching• Waste disposal in landfills• Production and distribution of natural gas

(made, bottled, piped to homes) leakageVast majority of methane present in today’s

atmosphere is estimated to be the result of human activities

Human Population Rising

• Population is rising• Human activity inceasing• Greenhouse gas emissions show little sign of

decreasing

Consequences

• Increase in photosynthetic rate• Change climate varies for different ecosystems• Extinction of some species• Melting glaciers• Melting sea ice would result in flooding

coastal areas

5.2.4 Precautionary Principle

• Ethical principle states action must be taken to prevent harm even if there is not 100% certainty that the activity will have severe consequences.

• People wishing to engage in activities that may cause changes in the environment must prove that their actions will not do harm

5.2.6 Arctic ecosystems• More ice melting each year• Less snow and more frozen rain• Mosquitoes moving in to new areas• Woody shrubs moving into areas that before were only moss

and lichens on tundra• Birds such as robins moving into new areas• Algae grows on underside of intact ice reducing productivity• Less ice less reflection snowballs heating effects• Melting and decomposition of tundra organic materials will

increase carbon dioxide levels