14-09-2013, 04:22 PM
Climate Change, Greenhouse Gases, and Fuel Cells: What is the Link?
There is a growing scientific consensus that increasing
levels of greenhouse gas emissions are changing the
earth’s climate. The natural greenhouse gases include
carbon dioxide (CO2), water vapor (H2O), nitrous oxide
(N2O), methane (CH4) and ozone (O3 ), and are essential
if the Earth is to support life. With the exception of
water vapor, carbon dioxide is the most plentiful. Since
the beginning of the Industrial Revolution in 1765,
burning fossil fuels and the increased energy needs of a
growing world population have added man-made, or
anthropogenic, greenhouse gas emissions into the
environment. Carbon dioxide constitutes a tiny fraction
of the earth’s atmosphere — about one molecule in three
thousand — but is the single largest waste product of
modern industrial society. The concentration of carbon
dioxide in the atmosphere has risen from about 280 parts
per million by volume to the current level of over 360
parts per million by volume and anthropogenically
caused atmospheric concentration of methane has
doubled. In the past 100 years, levels of nitrous oxide
have risen about 15%. Increasing concentrations of
greenhouse gases trap more terrestrial radiation in the
lower atmosphere (troposphere)