Greenhouse effect Because of the combustion of fossil fuels, the concentration of carb...

Greenhouse effect

Because of the combustion of fossil fuels, the concentration of carbon dioxide in the atmosphere is increasing. Research indicates that this will result in a greenhouse effect that will change the average global surface temperature. Assuming a vigorous expansion of coal use, the future amount A(t) of atmospheric carbon dioxide concentration can be approximated (in parts per million) by

where t is in years, t = 0 corresponds to 1980, and 0 ≤ t ≤ 60. Use the graph of A to estimate the year when the carbon dioxide concentration will be 450.