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We’ve completely obliterated our reliance on carbon based fuels. All our energy comes from renewal resources or even fusion. Our energy requirements continue to rise. Taking this to a deliberately ludicrous degree, whereby we’re capturing the sun’s energy, planet wide, via solar panels, we would essentially be diverting large amounts of sunlight that might otherwise have reflected our radiated back into space into our energy networks. Whatever that energy is used for our will ultimately be transformed Into heat. Some of that heat will be emitted into space via radiation, but I can’t help wondering if much of it will just stick around and continue to heat our atmosphere and oceans. Could our energy consumption increase indefinitely without affecting the ability of Earth to support our current ecosystem; or will be ultimately have to limit our energy use?

Edit for disambiguation purposes: I'm not sure my original question at posed has been understood. Ignoring existing greenhouse gas emissions, in fact ignoring any issue with GHG at all, as civilization advances and our energy requirements continue to rise, the energy that we do use to perform work will ultimately be transformed into heat. We'd basically be pumping heat into the atmosphere instead of GHGs. A hotter atmosphere still holds more energy and moisture. Could we end up overproducing heat via fusion? Or is radiation an effective way for the planet to balance this excess?

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  • $\begingroup$ You should consider that 70% of Earth surface is covered by water, so unless you place solar panels in the oceans, they will receive the same radiation. $\endgroup$ – David García Bodego Dec 24 '19 at 7:30
  • $\begingroup$ Fusion then. If we were to detonate a million fusion bombs around the globe things would undoubtedly get quite heated, but if we were releasing large quantities of heat as a result of clean fusion generation could we really rely on that heat escaping into space? It could only go via radiation. I figure there’d be plenty of construction and convection left over. $\endgroup$ – ThisLeeNoble Dec 24 '19 at 7:49
  • $\begingroup$ It is not that simple... If you place many fusion reactors, then you will need many heat exchangers to absorv the energy and reintroduce water in the system (or whatever element you use). This heat energy will go to water reservoirs and the atmosphere. So if you increase the atmosphere temperature, you will increase the water evaporation on the oceans. This water evaporation will reduce the temperature (if they are cummulus) or increase (if they are stratus). So one of them will keep the temperature of our planet and some others will trigger a huge greenhouse effect, as Venus. $\endgroup$ – David García Bodego Dec 24 '19 at 7:53
  • $\begingroup$ Our actual knowledge regarding cloud systems and formation is very limited to know what will happen in that scenario. $\endgroup$ – David García Bodego Dec 24 '19 at 7:54
  • $\begingroup$ Renewables are the way to go. Several studies exist meanwhile. This one states that Germany could be run completely on renewable (wind and solar) with the use 2.5% of its surface. oeko.de/fileadmin/oekodoc/…. It is not a qustion of technology any more ... $\endgroup$ – user18411 Dec 24 '19 at 10:14
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At present, only 51% of energy is reaching the earth surface (including oceans) in any given normal year with cloud cover as normal (excluding a peak sunspot cycle year which would have significantly reduced cloud cover across the earth). All of that energy makes its way out eventually as per a heat budget balance and so with reduced CO2 emissions of 410 ppms cut in half or greater to account for human contribution, one could address your question adequately from the GHG Effect with a simple > NO ISSUE for increased use of energy as the heat by-product would be 'lesser' or less potent as per the thermodynamic laws. Your question was: (Could our energy consumption increase indefinitely without affecting the ability of Earth to support our current ecosystem; or will be ultimately have to limit our energy use?) To answer the question succinctly, NO, I do not equate greater effects to ecosystems or affecting our ecosystems as a result of rising energy solar demand with a subsequent reduction of GHG by from human sources. Also to add to the answer, if CO2 emissions greatly and there was less fallout of CO2 in rainfall into our oceans, the ability for plankton to greatly increase would improve tremendously and therefore add to the balance effect of respiring greater amounts of oxygen into the atmosphere providing a better situation for animals species on land and in the water. For me, carbon reduction in the atmosphere and in the water would allow for greater photosynthesis and therefore, greater cooling in both systems, but especially in aquatic system in the Epipelagic zone where light would interact with microscopic plankton that generate huge amounts of 'cooling' oxygen for the earth systems. Here is a supportive article: https://www.sciencedaily.com/releases/2007/11/071117121016.htm

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  • $\begingroup$ I don't understand everything. But not all of the energy that reaches the ground makes it out again. Part of it is converted via photodynthesis or stored as heat in the atmosphere and ocean. Plankton (or in general photosynthetic life) is two fold, it does photosynthesis (produce oxygen), but can also contribute to deoxygenation and even anoxia when it grows out of control. $\endgroup$ – user18411 Dec 27 '19 at 17:10
  • $\begingroup$ Thank you EBV, I like your reply. Would plankton multiply out of control with reduced carbon in the atmosphere but reduced water temperature? I am alluding to that scenario, but not explicit enough I suppose. $\endgroup$ – J. Kaciulis Dec 27 '19 at 17:20
  • $\begingroup$ It can, and does, for example through pollution and inflow of nutrients and fertilizers (example algal blooms). But as said, even if we cut of all carbon emissions now, the ocean will continue to heat for a while. $\endgroup$ – user18411 Dec 27 '19 at 17:23
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Short answer: Yes, the ocean would continue heating for a while if we cut off all greenhouse emissions. Simply because CO2 has a long life span in the atmosphere and its effects will continue to be active for a long time, longer than human life spans.

Also, it may be that thresholds have already been passed that lead to positive feedbacks, like glacier retreat or desertification that amplify the forcing effects of greenhouse gases. Deforestation and wild fires are another such positive feedback, they release a lot of CO2 for immediate warming effect and expose a surface ready to be eroded and not available as a carbon sink any more.

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  • $\begingroup$ Why does hot dry weather increase lightning strikes? I know you haven't said so, but a lot of people believe it. To me it doesn't make sense. The cause of these fires is seldom lightning strikes and usually carelessness, vandalism and pyromania. Bringing these people to justice with draconian penalties would be the most effective way to reduce these fires. $\endgroup$ – Michael Walsby Dec 24 '19 at 11:36
  • $\begingroup$ You must have led a very sheltered life if you've never heard of pyromaniacs, and I doubt whether you believe the lightning strike theory for the current Aussie wildfires. In UK there has never been a time when the sun was hot enough to set woodland alight, which is just as well because such heat would have killed everyone in the country. $\endgroup$ – Michael Walsby Dec 24 '19 at 11:46
  • $\begingroup$ PS. Some cheat is manipulating the system. I have just been awarded 6 green points which weren't added to my total. Recently 60 points were deducted from my total by what the high command claimed was a mistake, but I can't have them back. Things like that happen all the time. Is it the same with you, or am I being picked on? $\endgroup$ – Michael Walsby Dec 24 '19 at 11:54
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    $\begingroup$ @MichaelWalsby you have several good questions here in the comments,if you want them answered please click on the ask question tab on top of the page. $\endgroup$ – trond hansen Dec 24 '19 at 15:04
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    $\begingroup$ @MichaelWalsby - Weather/fire warnings for dry lightning conditions are in news as I type + several serious fires started that way. Cold fronts triggering dry storms mostly. People in wet climates may find it hard to imagine how flammable drought + heatwave + windy conditions in Australia get; no outdoor welding, grinding, tractor driven 'slashers' allowed. Mowers and metal tracked bulldozers will start fires. Even mechanical grain harvesting. Less carelessness and arson helps but when conditions are extreme there will be fires. Global warming will increase the likelihood and severity. $\endgroup$ – Ken Fabian Dec 27 '19 at 23:18
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Heat does not accumulate on Earth. The Earth reaches an equilibrium temperature where outgoing thermal radiation balances incoming solar radiation, plus some smaller sources, of which our current energy production is a small part.

The geothermal heat flux from the Earth's interior is estimated to be 47 terawatts ... 0.087 watt/square metre, which represents only 0.027% of Earth's total energy budget at the surface, which is dominated by 173,000 terawatts of incoming solar radiation. Human production of energy is even lower, at an estimated 18 TW. wiki

Skeptical Science says: Greenhouse warming 100 times greater than waste heat

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  • $\begingroup$ "Heat does not accumulate on Earth" needs clarification; raising GHG levels causes heat accumulation until new equilibrium is reached. Good point with waste heat. $\endgroup$ – Ken Fabian Dec 27 '19 at 23:22
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The great hope for a carbon neutral future is, as you suggest, fusion power stations. Scientists are making good progress in this direction, but a commercial reactor is still two or three decades away. We won't have to limit the number of reactors because their production of dangerous wastes is negligible compared to fission reactors. The heat they will produce is not a problem either, as it will be dwarfed by the heat from natural sources like the sun and geothermal. Much of the small contribution our reactors make will radiate away into space.

We will have to limit our energy use for the simple reason that we will have to limit our population. The Earth does not have unlimited resources and populations cannot continue growing indefinitely. If we don't limit them ourselves in a planned and orderly way, nature will do it for us, and in the scramble for increasingly scarce resources, wars will become more likely. Water scarcity is already threatening to bring war to the Middle East and Africa. Whether the oceans will heat significantly before the carbon neutral energy sources can fully take up the task of providing our energy requirements, we shall have to wait and see.

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    $\begingroup$ Fusion energy has always been 30years away. The latest bet from scientists working on the case was between the 50s and the 80s. This century, that is. Much better are renewable energies. $\endgroup$ – user18411 Dec 24 '19 at 10:07
  • $\begingroup$ Yes, estimates have always been over optimistic, but what has changed is the progress made. Fusion has been achieved for about a second, and consumed as much energy as it produced, but it is a good first step. Scientists are working on an experimental reactor which they hope will be capable of a self sustaining fusion reaction, and will lead on to the development of a pioneer commercial reactor. We have never been at this stage before. It is hoped that by lining the torus with lithium tiles, the loss of neutrons can be reduced and more tritium manufactured to aid the fusion reaction. $\endgroup$ – Michael Walsby Dec 24 '19 at 10:37

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