GREENHOUSE GASES: FAST FACTS
(The following statistics were borrowed from the June, 1993, issue of the GEONews, newsletter for the Nebraska Geographic Alliance)
Carbon Dioxide: Carbon Contents of various fuels FUEL LBS of
Carbon (C) per (/) Common Units of Measure--
Wood (dry poplar) 1,032 lbs C / cord
Bituminous Coal (dry) 1,300 lbs C / metric ton
Diesel fuel 6.5 lbs C / gallon
Crude oil 255 lbs C / barrel
Gasoline 5.5 lbs C / gallon
No. 2 Diesel fuel 6.0 lbs C / gallon
Gasohol 5.3 lbs C / gallon
Ethanol 3.5 lbs C / gallon
Methanol 2.5 lbs C / gallon
Propane 9.5 lbs C / 100 cubic feet
Natural Gas 3.3 lbs C / 100 cubic feet
Methane: While carbon dioxide receives most attention in discussion of greenhouse gases, methane is also building up rapidly in the atmosphere as a result of various human activities.
** Main sources of methane include: rice paddies, termites, coal mines, land fills, and digestive tracts of animals. Estimated shares are as follows: Tundra, Bogs, Swamps 26%, Rice 20%, Livestock 15%, Burning of Vegetation 10%, Oil and Natural Gas 8%, Landfills 7%, Coal mining 6%, Wild animals & Termites 4%, Animal waste 3%, Oceans 1%.
** Concentration of methane in the atmosphere has more than doubled in the last 300 years, from 650 ppb (parts per billion) to 1,700 ppb and is still increasing at a rate of about 1% per year.
** Methane is 20-30 times as effective in trapping heat as CO2. While its atmospheric concentration is much lower, therefore, it makes up about 20-25% of the global warming phenomena, while CO2 is 50-55% and another 20-25% is CFC’s (chloro- fluorocarbons).
** Methane may be easier to control than CO2 or CFC’s, because its lifetime in the atmosphere is short (approx. 10 years). A cut in emissions of 10-20%, the report says, would stabilize atmospheric levels.
** Of that amount, 50-75% can be achieved by cutting emissions from farm animals by 50%. Among techniques recommended to this are improved feed and nutrition and hormone treatments to improve productivity.
** Total yearly emissions are placed at 425-675 million tons by many scientists. Of that amount, “human induced sources” are 60% and natural sources are 40%.
** One fear of the rise in CO2 and Methane levels in the atmosphere is that further global warming may cause the release of “methane locked in frozen tundra, in permafrost and in the sediments at the bottom of arctic seas...releasing vast new amounts of methane that would further promote atmospheric warming”. Of course, humans have not been logging atmospheric data, daily, for many years relative to Earth’s lifetime. That is why many individuals have been researching methods of predicting past weather: paleoclimatology.