Energy from the Sun comes down to Earth so we have the Sun up here and then we have the Earth. The energy is coming down to Earth and about thirty percent of that energy is reflected back into space and so only seventy percent of that initial energy actually makes it to Earth.
Now of that seventy percent that makes it to Earth, about one-third of it is absorbed by clouds and so it’s only about two-thirds of it that makes it to Earth. That’s supposed to be a bush by the way.
Next Lesson: Renewable and Nonrenewable Resources
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Of all that’s making it to the Earth, less than one percent of that energy is available to be used by plants and other primary producers of photosynthesis. Now, of that solar energy that is available to them to be used, ninety percent of that has lost its heat. There’s only about one percent that can be used to produce sugars.
Animals that consume plants, maybe that’s a herbivore or maybe an omnivore, that animal can only use one percent of the energy from plants they consume. We have these animals eating plants and then we have predators that feed on primary consumers and decomposers. We have animals that are eating the animals that are eating the plants so all of those predators that are feeding on primary consumers and decomposers, they can only absorb and use about one percent of the energy they take in.
If I went to that kind of quickly, let me just go over it again. We have all that energy coming from the Sun. Thirty percent is directly reflected back into space. Seventy percent of it makes it to Earth and makes it to the Earth’s surface of land and water. On the Earth’s surface, it drives weather patterns and ocean currents. Most of that energy is ultimately radiated back into space so only less than one percent is available to be used by plants.
Of that one percent, ninety percent is lost as heat so only one percent can be used to produce sugars and of that one percent, animals only use one percent of the energy from plants they consume and the predators feeding on those primary consumers and decomposers can only absorb and use one percent of the energy they take in so the number of steps in this chain must be limited for there to be sufficient solar energy to sustain life.