Increases in temperature increase the rate of the photosynthesis reaction by providing energy, this is accurate up to a point where enzymes denature meaning they go through irreversible physical changes and are unable to catalyse the reaction. An increase in light intensity also increases the rate of reaction up to a point where the maximum absorbance of light by chlorophyll is reached. After this the chlorophyll is unable to absorb further light and the rate reaches its maximum. An increase in carbon dioxide concentration will also cause an increase in rate as it is a raw product in the reaction of photosynthesis. The rate ceases to increase once the carbon fixation reaches a maximum.Bonus points:give the chemical equation for photosynthesis6CO2 + 6H2O --> 6O2 + C6H12O6