in ecology there are things called primary producers (plants) that are eaten by primary consumers (cows and chickens) and then there are humans, secondary consumers, that eat cows and chickens for energy.
The further we move from eating primary producers the more inefficient we become in consuming energy. Meaning, it requires a lot more natural energy consumption to support a human that lives on meat only as compared to a human that eats plants only. this inefficiency only magnifies when communities practice unsustainable food methods.
There are sustainable ways to eat meat, but (at least in the US) our current conventions of meat production are unsustainable and environmentally destructive.
The light independent reactions of photosynthesis are dependent on temperature. They are reactions catalysed by enzymes. As the enzymes approach their optimum temperatures the overall rate increases.
