4. (7 points) anthropogenic impacts on element cycles a. list three major modifications of anthropogenic activities on the carbon cycle. b. list two major impacts of anthropogenic activities on the nitrogen cycle c. list two major impacts of anthropogenic activities on the phosphorus cycle

1. Three major modifications of anthropogenic activities on the carbon cycle:

Level of atmospheric carbon dioxide has increased causing global warming because of burning of fossil fuels.Carbon is also emitted in other forms like methane by activities like oil gas leak.There is a reduction in level of oxygen.

2. Impact on nitrogen cycle:

Burning of fossil fuels has increased the level of atmospheric nitrogen leading to change in nutrient balance in trees. Release of nitric acid which results in smog and acid rain Impact on phosphorus cycle.

3.Two major impacts of anthropogenic activities on the phosphorus cycle

Increase in the amount of phosphorus by use of fertilizers which affect the fertility of soil.Untreated phosphates can turn into run off and flowing into-ocean leading to dead zones.

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