Humans have been burning fossil fuels rapidly for the past 250 years. as a result, the amount of atmospheric co2 has increased by about

By burning fossil fuels, people release in excess of 100 times more, about 26 billion tonnes of carbon dioxide, into the atmosphere every year (as of 2005)

Explanation:

The main forms of fossil fuels are petroleum oil, natural gas and coal. Fossil fuels have been used by man on a small scale for a long time. An increase in atmospheric CO2 may lead to global warming because of the so-called greenhouse effect. Light rays from the sun heat up the earth's surface. This produces heat rays which are radiated back into space. Some of the heat rays are trapped by atmospheric carbon dioxide and are responsible for warming the atmosphere.