claim: Over the three years from 1979 to 1982 when CO2 emissions were decreasing due to the rapid increase in the price of oil that drastically reduced consumption, there was no change in the rate of increase in atmospheric concentration of CO2 proving that humans were not the primary source for the increase in concentration.'
evidence: Human activities, primarily the burning of fossil fuels ( coal, oil, and natural gas ), and secondarily the clearing of land, have increased the concentration of carbon dioxide, methane, and other heat-trapping ( greenhouse ) gases in the atmosphere...There is international scientific consensus that most of the warming observed over the last 50 years is attributable to human activities.