Changing Our Atmosphere
Our Changing Atmosphere
Energy from the sun drives the earth?s weather and climate, and heats the earth?s surface; in turn, the earth radiates energy back into space. Atmospheric greenhouse gases (water vapor, carbon dioxide, and other gases) trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse.
Without this natural greenhouse effect, temperatures would be much lower than they are now, and life as known today would not be possible. Instead, thanks to greenhouse gases, the earth?s average temperature is a more hospitable 60?°F. However, problems may arise when the atmospheric concentration of greenhouse gases increases.
Since the beginning of the industrial revolution, atmospheric concentrations of carbon dioxide have increased nearly 30%, methane concentrations have more than doubled, and nitrous oxide concentrations have risen by about 15%. These increases have enhanced the heat-trapping capability of the earth?s atmosphere. Sulfate aerosols, a common air pollutant, cool the atmosphere by reflecting light back into space; however, sulfates are short-lived in the atmosphere and vary regionally.
Why are greenhouse gas concentrations increasing Scientists generally believe that the combustion of fossil fuels and other human activities are the
emissions, dioxide, carbon, greenhouse, concentrations, gases, earth?s, industrial, increased, human, energy, atmospheric, atmosphere, activities, about, space, revolution, release, oxide, nitrous, methane, however, heat, generally, fuels, fossil, concentration, been, back, years, without, weather, water, vegetation, vary, vapor, united, underlying, turn, trucks, trap, total, today?s, today, times, thanks, terrestrial, temperatures, temperature, technological, surface