Evaluate the impact on living organisms if the sun began to produce less energy and then finally burned out

If the sun produced less energy plants would not survive. They would lose the capability of photosynthesis and cellular reproduction. Due to this factor animals and humans would die out, simply because we would suffocate. That doesn't even cover how the sun will affect the atmosphere. Gases wouldn't evaporate and the perfect balance on Earth would dissipate, because the gas would tear at the atmospheric layers.