#Endless space 2 depletion points free#

вЂњLarge-scale exploitation of wind energy will inevitably leave an imprint in the atmosphere,вЂќ says Kleidon. So by setting up wind and wave farms, we convert part of the sunвЂ™s useful energy into unusable heat.

#Endless space 2 depletion points free#

And because no technology can ever be perfectly efficient, some of the free energy harnessed by wind and wave generators will be lost as heat. So to replace this, we would need to build enough sustainable energy installations to generate at least 17 TW. Of the 47 TW of energy that we use, about 17 TW comes from burning fossil fuels. вЂњA theory of the thermodynamics of the Earth system could help us understand the constraints on humankindвЂ™s sustainable use of resources.вЂќ Indeed, KleidonвЂ™s calculations have profound implications for attempts to transform our energy supply. вЂњKleidon is at the forefront of a new wave of research, and the potential prize is huge,вЂќ says Peter Cox, who studies climate system dynamics at the University of Exeter, UK.

Radical as his thesis sounds, it is being taken seriously. В“We have more effect on EarthвЂ™s energy balance than all earthquakes and volcanoes put togetherВ” вЂњItвЂ™s hard to put a precise number on the fraction,вЂќ he says, вЂњbut we certainly use more of the free energy than all geological processes.вЂќ In other words, we have a greater effect on EarthвЂ™s energy balance than all the earthquakes, volcanoes and tectonic plate movements put together.

This corresponds to roughly 5 to 10 per cent of the free energy generated by the global system. Humans currently use energy at the rate of 47 terawatts (TW) or trillions of watts, mostly by burning fossil fuels and harvesting farmed plants, Kleidon calculates in a paper to be published in Philosophical Transactions of the Royal Society. Instead, we should be looking at how much useful energy вЂ“ called вЂњfreeвЂќ energy in the parlance of thermodynamics вЂ“ is available from the global system, and our impact on that. But this ratio is misleading, Kleidon says. Much of the rest is dissipated as heat, which we cannot harness.ДЄt present, humans use only about 1 part in 10,000 of the total energy that comes to Earth from the sun. When energy from the sun reaches our atmosphere, some of it drives the winds and ocean currents, and evaporates water from the ground, raising it high into the air.

His logic rests on the laws of thermodynamics, which point inescapably to the fact that only a fraction of the solar energy reaching Earth can be exploited to generate energy we can use. In effect, he says, we will be depleting green energy sources.

Build enough wind farms to replace fossil fuels, he says, and we could seriously deplete the energy available in the atmosphere, with consequences as dire as severe climate change.ДЄxel Kleidon of the Max Planck Institute for Biogeochemistry in Jena, Germany, says that efforts to satisfy a large proportion of our energy needs from the wind and waves will sap a significant proportion of the usable energy available from the sun. He concludes that it is a mistake to assume that energy sources like wind and waves are truly renewable. Yet that is the provocative suggestion of one physicist who has done the sums. WITNESS a howling gale or an ocean storm, and itвЂ™s hard to believe that humans could make a dent in the awesome natural forces that created them.