tag:blogger.com,1999:blog-8524070301101240472.post3938055081731594120..comments2023-09-28T08:13:11.489-07:00Comments on Only In It For The Gold: Limits to Clean EnergyMichael Tobishttp://www.blogger.com/profile/08229460438349093944noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-8524070301101240472.post-72233040394146701632009-01-28T09:20:00.000-08:002009-01-28T09:20:00.000-08:00On the off chance that comments are still open, an...On the off chance that comments are still open, <A HREF="http://www.boston.com/bostonglobe/ideas/articles/2009/01/25/the_other_global_warming?mode=PF" REL="nofollow">an article about Eric Chaisson in the Boston Globe</A>. "In it" had them scooped by 5 months! ;)tidalhttps://www.blogger.com/profile/08979480547719289608noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-55923603975260013592008-07-30T19:13:00.000-07:002008-07-30T19:13:00.000-07:00ac, humans appropriate the majority of the net pri...ac, humans appropriate the majority of the net primary productivity of the earth, not leaving much slack in biotically active areas, but there is plenty of sunshine in the larger barren areas. <BR/><BR/>It is a nice question. I don't have a ready answer. Anyone?Michael Tobishttps://www.blogger.com/profile/08229460438349093944noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-89595620489382280102008-07-30T00:59:00.000-07:002008-07-30T00:59:00.000-07:00Michael, what was your estimate of the fraction of...Michael, what was your estimate of the fraction of solar energy currently appropriated for food?achttps://www.blogger.com/profile/08817718132877704613noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-16526127544372108572008-07-26T18:46:00.000-07:002008-07-26T18:46:00.000-07:00Realistic numbers:World human population stale at ...Realistic numbers:<BR/><BR/>World human population stale at 9 billion of us.<BR/><BR/>Total energy requirement (not including food), all sources: 800 exajoules.<BR/><BR/>Possible.<BR/><BR/>Not probable.David B. Bensonhttps://www.blogger.com/profile/02917182411282836875noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-59175886405077683812008-07-26T08:23:00.000-07:002008-07-26T08:23:00.000-07:00Tidal, Chaisson acknowledges your point: "Note tha...Tidal, Chaisson acknowledges your point: "Note that utilizing solar energy that naturally affects Earth (including solar-driven tides, wind and waves), without generating any further energy via nonrenewable supplies, would not cause additional heat."<BR/><BR/>After that statement he immediately points out that solar collectors in space do not qualify as renewable under this definition. Those or fusion, which I have always thought of as the long-range hopes for energy growth, both tax the viability of the biosphere.<BR/> <BR/>So we should treat 100% renewables as the goal. That's a lot of energy, but it's diffuse, and the biosphere needs some of it.Michael Tobishttps://www.blogger.com/profile/08229460438349093944noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-65033618879782685122008-07-25T16:30:00.000-07:002008-07-25T16:30:00.000-07:00Beat cha to it. However two serious points:1: Ch...<A HREF="http://rabett.blogspot.com/2008/07/darth-entropy-eats-space-cadets-lunch.html" REL="nofollow"> Beat cha to it</A>. However two serious points:<BR/><BR/>1: Chaisson is using the majik of compound growth. It is not clear that this will happen.<BR/><BR/>2: Space based power is shorthand in some circles (Marshall Institute) for large lasers in space. Chaisson is very anti star wars<BR/><BR/>3: I got a better title for my post too.EliRabetthttps://www.blogger.com/profile/07957002964638398767noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-12261249842044730782008-07-25T11:34:00.000-07:002008-07-25T11:34:00.000-07:00Jordan, I actually touched on the space question: ...Jordan, I actually touched on the space question: "no escape short of escape velocity".<BR/><BR/>I wonder what the earth, at the bottom of a gravity well, will have to sell to the people in space. The number of launches from earth will be severely limited, presuming the space elevator idea will go nowhere...Michael Tobishttps://www.blogger.com/profile/08229460438349093944noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-6363766555517320402008-07-25T10:10:00.000-07:002008-07-25T10:10:00.000-07:00Your industrial heat by-product limit to growth on...Your industrial heat by-product limit to growth only applies if you assume all of humanity's energy use remains on Earth. Any scenario that involves continuing exponential growth in energy use quickly gets into Dyson sphere territory (as with any good piece of science fiction). It's certainly still a limit to Earth-based energy growth. In any case, my point is that you can't argue against magical thinking like infinite growth by pointing out flaws in the logic, because magic can always fix any problems - that's why it's magic.Jordanhttps://www.blogger.com/profile/12415965539559125950noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-17382356836172727592008-07-25T09:44:00.000-07:002008-07-25T09:44:00.000-07:00Tidal, I think your point is sound. I am not entir...Tidal, I think your point is sound. I am not entirely sure how much energy we can extract from the sun; there does seem to be an entropy limit somewhere.Michael Tobishttps://www.blogger.com/profile/08229460438349093944noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-3017199054467550702008-07-25T09:27:00.000-07:002008-07-25T09:27:00.000-07:00I must be having a brain cramp here. I've read sim...I must be having a brain cramp here. I've read similar critiques in the past, but I don't really understand where the extra heat is coming from? Leaving aside nuclear or possibly geothermal, and calling "clean energy" solar PV, solar thermal, wind, tidal, maybe biofuels, etc. Where does the "extra" heat come from? Whether we intercept and use some fraction of the solar, hydro, rotational, gravitational energy fluxs and dissipate low-grade heat in the process, OR it's not used by us and just dissipates on it's own... how would we be net "heating" the planet? I can get how maybe some of the visible light that might otherwise get reflected would be converted to infrared, but it seems so tiny... Is this just a function of "those tiny things add up with geometric growth"?<BR/><BR/>I can see where nuclear or fossil fuel burning adds heat, but I have trouble comprehending it with the truly "clean energies". Like I said, probably a brain cramp - I am just trying to grasp this...<BR/><BR/>By the way, these kind of conclusions are genuinely depressing. I remember reading a similar description in Sayres' online manuscript, now called "Unearthed: The Economic Roots of our Environmental Crisis", that you pointed to on the globalchange group last year. It's a somewhat interesting read, but every turn toward "solution" is eventually met with another "it's an environmental/resource dead end!"... It's hard even reading it.tidalhttps://www.blogger.com/profile/08979480547719289608noreply@blogger.comtag:blogger.com,1999:blog-8524070301101240472.post-53444751757764403262008-07-25T00:20:00.000-07:002008-07-25T00:20:00.000-07:00Well, let's be careful with terminology.If you...Well, let's be careful with terminology.<BR/><BR/>If you believe Ayres&Warr, it's not energy, it's work = efficiency*energy that affects GDP growth (i.e., it's a big chunk of Total Factor Productivity, which is about 60% of the growth.)<BR/><BR/>This is not an argument with the fundamental idea of limits, just that efficiency matters a great deal.<BR/><BR/>I think I pointed you at some of this before, but let me know if not, and I can post some URLs.John Masheyhttps://www.blogger.com/profile/17786354229618237133noreply@blogger.com