In nature, photochemistry is of immense importance as it is the basis of photosynthesis, vision, and the formation of vitamin D with sunlight. Photochemical reactions proceed differently than temperature-driven reactions.

A nice example is the production of Vitamin D out... (More)

When fertilizer is introduced into aquatic ecosystems it can cause phytoplankton to multiply rapidly. large increases in the number of phytoplankton can cause oxygen depletion in the water, leading to suffocation of the organisms in the water.