Submitted by ebb5 t3_y7s95g in askscience
Guest426 t1_it2e9qf wrote
Reply to comment by dynamictype in Is our sleep pattern based off the length of the day? by ebb5
Correct, however.
Energy in = energy out + energy stored
When the Sun is creating sugar the Earth can reject the remaining heat. But when we start converting that sugar into heat, the Sun does not turn off, it keeps supplying the same amount of heat as before. So now if we take the constant supply of heat from the Sun and we add the conversion of stored sugar energy into heat, without increasing the Earths capacity to reject heat, at a certain rate of sugar burning we will overwhelm the Earth's heat rejection capacity and the internal temperature of the system will rise.
dynamictype t1_it2fd5g wrote
But we're planting plants and raising livestock. As humans expand we're the ones adding more stored energy. The net energy is still the same. Every bit of sugar burned was heat saved earlier in the growing season.
Guest426 t1_it2jsv7 wrote
But as we burn that sugar, the Sun keeps supplying the same amount of heat as it was while the sugar was being created.
Imagine a river, a damb and a reservoir.
The river flows to the reservoir and through the damb. All of the water came from the river, but if we release too much from the reservoir at once, the damb will overflow.
dynamictype t1_it2n236 wrote
But the sugar absorbed the energy when it was grown
It's net zero. We can't be generating more heat than the sun is supplying, that breaks the conservation of energy. It's like the fallacy in The Matrix that humans could generate energy via body heat. It's always zero sum.
If I grow corn in June, the corn is absorbing the heat from the sun and converting to sugar. The net effect of growing corn reduces the total heat of the Earth.
When someone eats the corn and their body temp is increases the heat is released. Since all across the earth we are pretty much constantly growing and eating this mostly all evens out. And even if it's not perfectly even, due to seasons, you still over the course of the year have net zero heat vs if humans didn't exist at all.
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