Question

which statement best describes a human influence on the biogeochemical cycles?
increased eutrophication caused by high levels of nitrogen and phosphorous
increased nitrates available due to inaccurate methods of denitrification
increased global warming due to alternative energy sources
increased amount of water that is available to freshwater ecosystems

Explanation:

Human activities like agricultural fertilizer use and sewage release introduce excess nitrogen and phosphorus into water systems. This triggers eutrophication, a well-documented human impact on biogeochemical (nutrient) cycles. The other options are incorrect: inaccurate denitrification methods are not a major human source of increased nitrates; alternative energy sources reduce, not increase, global warming; human activities generally reduce freshwater availability for ecosystems, not increase it.

Answer:

A. increased eutrophication caused by high levels of nitrogen and phosphorous