Examples
High respiration rates from mass global population
Deforestation
Do you see the tectonic plates are moving away from each other
The factor that would least affect photosynthesis is Nitrates in the soil.
Photosynthesis is the process by which plant make their own food by utilizing energy from sunlight, water and carbon dioxide. The limiting factors that affect photosynthesis are the light intensity, carbon dioxide concentration, temperature and water. Without enough light, a plant cannot photosynthesize very quickly, even if there is plenty of water and carbon dioxide.