Sustainability

The modern industrial way of life has relied on the increased use of fossil fuels, returning to the atmosphere some of the carbon that was sequestered naturally over billions of years. The earth’s atmosphere acts like the roof of a greenhouse, allowing short wavelength (visible) solar radiation from the sun to reach the surface, while greenhouse gases like CO2, water and methane absorb the long–wavelength heat that would otherwise be emitted back. Concentrations of carbon dioxide now exceed the natural range of the last two million years by 25%, hence the net effect of human activities since 1750 has been one of warming.

The carbon cycle: The carbon cycle refers to the transfer of carbon, in various forms, through the atmosphere, oceans, plants, animals, soils and sediments. Living organisms return carbon to the atmosphere when they respire, decompose or burn. Methane is released through the decomposition of plants, animals and other hydrocarbon material (fossil fuels). The majority of carbon that was present in the early atmosphere is now stored in sedimentary rocks and marine sediments. COther carbon sinks are store carbon and include the atmosphere, oceans, fossil fuels such as coal, petroleum and natural gas, living plants and organic matter in the soil.