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.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.