What are the requirements for photosynthesis to occur, and what is the role of atp in this reaction?

For photosynthesis to occur, the necessary parts are sunlight, water and carbon dioxide or CO2. The role of ATP in the reaction is that it is itself generated by the first stage of photosynthesis, and is therefore a product of the reaction. It provides energy for the next stage.

Iwould say overuse ( but not 100% sure ) in the u.s. we tend to overuse water by leaving it running, throwing it away, taking long showers, etc.