The new set of oscillations and negative feedbacks certainly won't be identical to those that have been active for the past few centuries. But that doesn't mean they'll be identical to those that were in place before the Isthmus of Panama closed.
It's too late to keep the arctic sea ice from melting. Turnover of sea ice is a much faster process than politics, and any intervention large enough to save the sea ice will require political approval in some form. The melting of the arctic sea ice is a positive-feedback loop. Less ice means more sunlight absorbed, which means less ice. So it doesn't tend toward an equilibrium in the middle, but rather acts as a switch between lots of sea ice and none. We've warmed the planet enough to flip that switch, and it's happening faster than we can act to stop it. Many atmospheric processes are even faster, and will inevitably respond. Other processes, however, are much slower. The amount of heat, O2, and carbon in the oceans is large enough that it takes years to change dramatically. Ice sheets flow at a glacial pace. We have time to intervene before these effects play out. -- Nuclear reactors do not provide unlimited energy, and never will unless they're fusion reactors. The amount of fissionables recoverable from the earth's crust is only on the same order of magnitude as the amount of coal, in terms of available energy. Exponential growth will use it up in a matter of decades. However, the sun does provide unlimited energy. Of course, the size of the sun is finite too, but it's unlimited in the sense that we'll run out of something else first. Even if we could turn the entire mass of Jupiter into housing and had enough population to occupy it all, the sun would still be putting out more energy than we could use. -- On Jan 26, 5:41 am, "Eugene I. Gordon" <[email protected]> wrote: > The global temperature is slowly increasing with superimposed temperature > fluctuations. I am not exactly sure why the planet goes through these > periods but I suspect it is partly related to changes in ocean currents and > motions of land or sea bottoms. However, there is every reason to believe > the global temperature will reproduce the extremes of the past. It is headed > to 24 C according to geological data. Sure there is ample time before the > temperature peaks out. If needed we will have thermonuclear reactors to > produce unlimited energy, and we can live in domed or underground cities and > carry personal A/C. Man will survive even if all the ice melts and many > forms of life disappear. It will be a very different world with far fewer > people. Alternately, we can maintain it as it is by controlling the > temperature changes. > > -----Original Message----- > From: [email protected] > > [mailto:[email protected]] On Behalf Of Sam Carana > Sent: Sunday, January 25, 2009 10:33 PM > To: geoengineering; geo-engineering; greenhouse effect > Subject: [geo] Re: What is geo-engineering? > > One way to define a runaway greenhouse effect is in terms of geoengineering, > i.e. a runaway greenhouse effect would require geoengineering to mitigate. > > Another definition of a runaway greenhouse effect is that the primary cause > is no longer human activity, but that it feeds on itself. Higher > temperatures turn soils and oceans into net emitters, rather than sinks. > > Yet another way to define a runaway greenhouse effect is in terms of risk, > which is an important consideration, as the risk of a runaway greenhouse > effect will for many be the very reason to go ahead with geoengineering. A > runaway greenhouse effect would come with a rise in greenhouse gases that > takes place with such speed that many species will go extinct, unable to > adjust to such rapid changes. The decrease in biodiversity would be > unacceptable and thus justify geoengineering. > Moreover, human beings as a species will face the risk of total extinction, > particularly if many species of animals and plants that humans depend on > will disappear. > > Cheers! > Sam Carana > > On Mon, Jan 26, 2009 at 1:15 PM, dsw_s <[email protected]> wrote: > > > We're apparently using the phrase "runaway global warming" > > differently. As I understand it, there are a set of oscillations and > > negative feedback loops keeping the state of the climate within a > > certain subset of its possible states; if various exogenous variables > > (insolation, CO2, position of continents, etc.) go beyond a certain > > range, a positive feedback loop takes over until the state of the > > climate reaches another such set of oscillations and negative feedback > > loops. The positions of the continents are still essentially as they > > have been for the past few million years: in particular there's a > > Tibetan Plateau and there's an Isthmus of Panama. So the new regime > > after this episode of positive feedback is likely to be drawn from the > > repertoire of ice ages and interglacial periods that we've seen in > > geologically recent time. > > > If "runaway global warming" means going all the way back to a climate > > pattern like those that prevailed through most of geologic time, even > > though we still have the oddity of an Atlantic/Pacific separation that > > extends from the antarctic to the arctic, then I think we probably > > have time to prevent it, if it's even in the cards at all. And there > > are probably a completely new set of possibilities that come with > > interventions like putting a few terawatts of wind turbines in the > > westerly winds above the trade winds. > > > On Jan 25, 10:46 am, "Eugene I. Gordon" <[email protected]> wrote: > >> How many of you are familiar with thewww.scotese.comwebsite?If not > >> take a few minutes; it is a mind-boggling experience. Christopher > >> Scotese is a well known and highly respected geologist. He has one > >> page for global average temperature going back 540 million years. The > >> data is derived from proxy studies. It is a science that is evolving > >> and the data values have migrated a bit over the years. For example, > >> he now shows 24 C as the maximum global average whereas some years > >> back it was 22 C. The minima has changed from 12 C to 10 C except > >> for the current period wherein it bottomed out at 12 C and an earlier > >> period when it turned upward in midstream. Some special short lived > >> (million year) peaks (delta +2 degrees C above the maximum) occurred as a > result of major asteroid hits and those destroyed most life on Earth. > > >> [Man almost certainly evolved because of the latest increase to about > >> 15 C from an ice age minimum of 12 C.] > > >> The global average has never started up and turned around before > >> reaching the maximum. Clearly there is a positive feedback mechanism > >> in global temperature change and once on the way up there has been no > >> reversal. The changes are most likely related to motion of > >> continents, so the changes survive over many millions of years. > > >> If we do nothing the Earth is certainly headed for 22-24 C > >> independent of AGW. AGW only changes the upward slope. > > >> In my view only geoengineering can intervene and I have no doubt that > >> eventually it will be implemented. There will be no catastrophic > >> runaway to > >> 24 C. My interest is in earlier rather than later implementation. It > >> is in the best interests of my great grandchildren. I am too old for > >> it to make any difference for me. > > >> -gene > > >> -----Original Message----- > >> From: [email protected] > > >> [mailto:[email protected]] On Behalf Of dsw_s > >> Sent: Sunday, January 25, 2009 2:27 AM > >> To: geoengineering > >> Subject: [geo] Re: What is geo-engineering? > > >> I think saving the arctic sea ice is a lost cause. Saving the > >> permafrost probably is too. We need to deal with the effects of > >> runaway global warming, not pin our hopes on stopping it. If that's > >> where we draw our Maginot Line, then we're still in the situation > >> where the least that might be necessary is far in excess of the most > >> that might be politically possible. Dealing with the effects -- > >> having a warmer world with more small hurricanes over ocean instead > >> of bigger stronger ones making landfall, having enough snowfall on > >> the ice sheets to more than offset the increased loss of ice, having > >> global patterns of precipitation that are compatible with agriculture, > limiting ocean acidification -- that's geoengineering too. > > >> On Jan 24, 10:18 pm, Andrew Lockley <[email protected]> wrote: > >> > I personally feel that if we don't address BOTH geoengineering and > >> > low-carbon economy satisfactorily at Copenhagen then we're at a > >> > serious risk of entering 'game over' situations. > > >> > I think that a lot of work needs to be done to put forward a > >> > package of research that should be backed by the summit to > >> > establish a direction for geo-eng. It is not going to be easy to > >> > build consensus to support and fund this research, but it's the > >> > chance for the funding we all need. I personally am working where I > can to push the 'green' > >> > organisations to accept it as an essential part of the climate > >> > solution mix. > > >> > A > > >> > 2009/1/25 Stuart Strand <[email protected]>: > > >> > > The biosphere removes vast amounts of CO2 from the atmosphere > >> > > yearly > >> reversing the year to year trend dramatically. We control 10% of the > >> terrestrial biosphere. We can use that control to significantly > >> reduce the lifetime of CO2 in the atmosphere. > > >> > > Glad to hear that the national sovereignty problem has been disposed > of. > > >> > > = Stuart = > > >> > > Stuart E. Strand > >> > > 167 Wilcox Hall, Box 352700, Univ. Washington, Seattle, WA 98195 > >> > >voice 206-543-5350, fax 206-685-3836 > >> > > skype: stuartestrand > >> > >http://faculty.washington.edu/sstrand/ > > >> > > -----Original Message----- > >> > > From: Eugene I. Gordon [mailto:[email protected]] > >> > > Sent: Saturday, January 24, 2009 2:33 PM > >> > > To: Stuart Strand; [email protected]; [email protected] > >> > > Cc: 'John Nissen'; 'greenhouse effect'; 'geoengineering'; > >> 'geo-engineering' > >> > > Subject: RE: [geo] Re: What is geo-engineering? > > >> > > Stuart: > >> > > I am not sure why you say it is overwrought. After all, we agree > >> > > precisely on preventing ice melt and the importance of taking > >> > > large amounts of CO2 from the atmosphere. I added reducing > >> > > sunlight, also a possibility which you commented on but I missed > >> > > your point. So again, > >> why is it overwrought. > > >> > > What you may have missed is the discussion of CO2 lifetime in the > >> > > atmosphere. I have circulated material that shows pretty clearly > >> > > that it is over 1000 years. No one took exception. If it is > >> > > reducing > >> > > CO2 emissions buys us nothing in the short term other than a > >> > > reduction in use of fossil fuels, which is a valuable thing to do > >> independent of CO2 emissions. > > >> > > The issue of other governments and what they desire has been > >> > > addressed in these exchanges way back. I suspect that you are > >> > > right that the Russians might prefer continued ice melt. I did > >> > > not realize that the atmosphere had been nationalized. If it has > >> > > not been > >> nationalized then screw the Russians. > > >> > > -gene > >> > > -----Original Message----- > >> > > From: Stuart Strand [mailto:[email protected]] > >> > > Sent: Saturday, January 24, 2009 3:25 PM > >> > > To: [email protected]; [email protected]; > >> > > [email protected] > >> > > Cc: 'John Nissen'; 'greenhouse effect'; 'geoengineering'; > >> 'geo-engineering' > >> > > Subject: RE: [geo] Re: What is geo-engineering? > > ... > > read more » --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
