The energy and emergy of the internet

Recent years have seen a flurry of energy-efficient networking research. But does decreasing the energy used by the Internet actually save society much energy? To answer this question, we estimate the Internet's energy consumption. We include embodied energy (emergy)---the energy required to construct the Internet---a quantity that has often been ignored in previous work. We find that while in absolute terms the Internet uses significant energy, this quantity is negligible when compared with society's colossal energy use.