First open thread of the new year. A time for ‘best of’s of climate science last year and previews for the this year perhaps? We will have an assessment of the updates to annual indices and model/data comparisons later in the month.
Climate science from climate scientists...
http://solberg.snr.missouri.edu/gcc/
Warning, signs of scientific/mathematical humor; from the abstract of one of the 2013 papers linked on that page:
There is a new WP plug-in for fast share content. http://wordpress.org/plugins/repostus/
Comments on a couple of earlier points.
Diogenes, concerning reforestation. I posted some comments, last year, from a climate scientist who has done calculations in the past about the amount of carbon in the Amazon rain forest (and this was when it was larger). The upshot is that he calculated that a mature forest the size of the Amazon, every 17 years, would be needed to counter emissions (as of a year or two ago). Now, if emissions start to decline, the amount of reforestation would need to decrease but, since we have to decrease the amount of carbon in the atmosphere, let’s just assume 1 mature Amazon rain forest every 17 years is required. Is that likely or even possible?
Wili, did Anderson say how a “carbon free” energy source might be constructed? Can cement be produced without carbon emissions? Can resources needed for renewable energies (or nuclear) be obtained without carbon emissions? Maybe substitute materials can be produced using only carbon free energy sources, in order to provide those carbon free energy sources, but that sounds like a tall order, to me.
Not that I’m saying nothing should be done. Surely any actions that may make our situation less dire than it otherwise would be must be a good thing. But, as others have also pointed out, many of the things we take for granted as being needed or desirable (e.g. economic growth) have to go. Anderson actually implies that growth may be possible at a later stage but I don’t know whether he’s just being non-committal or actually believes growth can return once we get the climate under control (at 2C or some other dangerous figure).
I was reading up about Rossby waves only a few months ago and then when the US’s big freeze came it kind of put the theory into reality. The unique slow meandering haphazard undulations often having large degrees of NS amplitude extending this time to florida seem to be getting more pronounced over the past 5-10 years. I am aware this is caused by the narrowing of temperature range in the mid altitudes between the tropics where the jet stream begins and the arctic/Antarctic regions. What I’m not sure about is why this extreme southerly excursion of the rossby wave has occurred in the northern winter, you would think the NS temp gradient is wider then than in summer? I have noticed that over Australia our W-E trans continental weather patterns seem to be slowing down considerably resulting in our record heat waves this summer where we had a massive pool of stagnant hot air over the centre of the country just getting hotter and hotter which eventally drifted over us in SE Queensland last Saturday. We endured temps of 44C breaking the old record by two whole degrees. Since both events have occurred pretty much simultaneously could they be linked??.
First reported by NASA
Stratospheric Polar Vortex Influences Winter Cold, Researchers Say
December 1, 2001 http://earthobservatory.nasa.gov/Newsroom/view.php?id=22082
The study paper was published 2004 http://journals.ametsoc.org/doi/abs/10.1175/1520-0469(2004)061%3C1711:DMFSIO%3E2.0.CO;2
Stratospheric Harbingers of Anomalous Weather Regimes
Science 19 October 2001:
Vol. 294 no. 5542 pp. 581-584
DOI: 10.1126/science.1063315
Tom Weddle asked (@#154): “Can cement be produced without carbon emissions?” “Can resources needed for renewable energies (or nuclear) be obtained without carbon emissions?” Yes and yes (or at least with much lower carbon emissions), and that is already happening in many places.
But those are off topic from Anderson’s main point, which is that we can’t sit around waiting for alternatives to scale up. We don’t have that kind of time. We don’t have any time. We have to reduce emissions immediately, and only ‘demand’ reduction can happen that fast. So the harder question right now is: Can we reduce carbon demand rapidly and humanely (without causing too much economic distress for those least able to cope with it)?
I don’t know the answer to that, but the longer we wait, the less likely that the answer can be positive.
(reCaptcha wisely though stammeringly entones: mmanaged goblin)
The association between stratospheric weak polar vortex events
and cold air outbreaks in the Northern Hemisphere (2010)
The Science of the Polar Vortex/Jet Stream
A collection of some study papers since 2001.
#154–“Can cement be made carbon-free?”
Funny you should ask!
http://phys.org/news/2012-04-solar-thermal-cement-carbon-dioxide.html
Of course, that’s only *can be*, but still…
Equally of course, growth has to stop at some point, just as you say–and as Dr. Tom Murphy demonstrates in that video Hank posted, and the “Do The Math” blog I’ve linked previously:
http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/
Tony Weddle #154,
“let’s just assume 1 mature Amazon rain forest every 17 years is required. Is that likely or even possible?”
With seven billion people in this world, almost any type of project is possible, if resources and incentives are made available, and leadership is provided. I see no reason why forests of this magnitude could not be planted in your time frame; I don’t know how long it takes for forests to reach your definition of ‘mature’, and whether that would be consistent with your time frame.
Look, according to the article below, the USA has spent somewhere in the neighborhood of seven trillion dollars on R&D since WWII. Obviously, not all of it has been on energy, but directly and indirectly much has been spent on energy because of the fundamental role energy plays in a high-tech society. We have a tremendous amount of developed capability for producing, converting, and storing energy sitting on the shelves and ready to go because of this R&D, and the complementary R&D performed by the rest of the world. So, much is POSSIBLE for improving our energy posture based on what we have in the here-and-now. However, for a multitude of reasons, that’s where this capability remains, sitting on the shelves! So, there is a huge gulf between what is ‘possible’ and what is ‘likely’ in the types of energy we use and how efficiently we use it. When one reads between the lines of Hansen’s Plos One paper, one senses Hansen’s frustration in discussing the emissions reductions that could have been achieved relatively painlessly with existing technologies decades ago, thereby circumventing much of the climate problem we are seeing today. I, like you, am not optimistic that conditions today have changed all that much in order for the ‘possible’ to become ‘likely’.
http://www.thenewatlantis.com/publications/the-sources-and-uses-of-us-science-funding
“Anderson actually implies that growth may be possible at a later stage but I don’t know whether he’s just being non-committal or actually believes growth can return once we get the climate under control (at 2C or some other dangerous figure).”
Anderson has an acceptance problem. The first part of his presentation, where he states the problem and consequences of various scenarios, is quite grim and quite realistic, and from my view, not all that different from McPherson. If he ended after the first part, he would basically be treated by his audience the way McPherson is treated; that is to say, ridiculed and ignored. So, he needs to add some cause for optimism to keep his audience on board. To me, that’s the only value of his recommendations. They are based on a 2 C target, which he states in earlier papers is too high by a factor of two, the latter being aligned with Hansen’s target. If he based his computations and recommendations on Hansen’s target, then one would see how narrow and limited our options really are.
For Tony Weddle, LMGTFY
citing articles for “Cement from Sea Water – A Concrete Cure for Global Warming” which appeared in Sci. Am. some years back. Most of your questions, tho’ you may think they were rhetorical, have interesting answers.
http://onlinelibrary.wiley.com/doi/10.1002/cssc.201100473/pdf
Wiley Online Library (you need to create a free userid there to see the abstract and info; the full article is paywalled*)
ChemSusChem
Special Issue: Carbon Dioxide Recycling
Volume 4, Issue 9, pages 1194–1215, September 19, 2011
Quadrelli, E. A., Centi, G., Duplan, J.-L. and Perathoner, S. (2011), Carbon Dioxide Recycling: Emerging Large-Scale Technologies with Industrial Potential. ChemSusChem, 4: 1194–1215.
doi: 10.1002/cssc.201100473
“Cited by” fifty-two other papers, to date; those are listed on this page:
http://onlinelibrary.wiley.com/doi/10.1002/cssc.201100473/citedby
_____________________
Aside:
To paraphrase Vonnegut, it was a really nice planet, and lots of smart people had good ideas that could have saved it, if it wasn't for their damned stupid economic system that locked up most of the needed information and kept people from talking to each other freely during the emergency until far too late .....“Is the jet stream reacting to the lack of Arctic ice? – ”
Chris the biggest influence positioning the jet stream is the location of the coldest atmosphere, or now a days : meso atmospheres. By logic, if there is less thick ice, the atmosphere above the Arctic Ocean becomes warmer, therefore the coldest zone splinters and becomes smaller. Smaller cold zones – instead of one gigantic cold area covering the entire Northern half of the NH – would cause the jet stream to meander more, instead of closely reflecting a world wide bulge of winter, therefore more cold weather like now in central North America, and extreme warmth like in NW Europe is possible simultaneously when it should normally be colder everywhere at once. The last 10 years of Arctic sea ice coverage was at all time low values, therefore the last 10 years of weather extremes.
For those wondering where the coldest atmosphere is , look at the 700 or 500 mb charts for temperature. The coldest spot is exactly where the lowest temperatures are. Unfortunately not even NASA do DWT charts, Density Weather Temperatures, so we settle for 700 or 500 mb current data. Temperature at About 600 mb closely resembles the DWT. So by extrapolation anyone can calculate the center of the coldest atmosphere in the world. Which was in Illinois and Siberia yesterday. But Illinois area seemed more expansive. I call the center of the coldest atmosphere in the world the Cold Temperature North Pole
http://eh2r.blogspot.ca/.
I read recent Mike Mann superb comments again, but not on RC?? Mike, follow the outline of the jet stream, compare from now with respect to 30 years ago, holistic data suggests a vast difference……
Hank Roberts: ” … waste heat from energy production at the rate our economy has been growing … Purely based on the rate of growth of energy use, Earth reaches the boiling point of water …”
Please stop equating “energy” with “fuel”. They are not the same thing, despite the fossil fuel industry advertising campaigns that ALWAYS refer to fossil fuels as “energy”.
We don’t need to “produce” energy. We are surrounded by vastly more energy than we can possibly use. We just need to convert it into useful forms.
ooops 165 DWT is Density Weighted Temerature….
> By logic, if there is less thick ice, the
> atmosphere above the Arctic Ocean becomes warmer
Is that right? Albedo, emissivity, are surface effects not depending on thickness.
But yeah
https://nsidc.org/cryosphere/arctic-meteorology/factors_affecting_climate_weather.html
How do climate models account for aeresols, sulfur etc injected into atmosphere by coal fired power plants in China, India and other countries? If these countries are successful at cleaning emissions and reducing aerosols do the models predict an acceleration of warming due to cleaner air? What if any part of current “flatlining” might be attributed to these aerosols?
Just an interested amateur here: Remind me why we went to the trouble of re-establishing/maintaining our ozone layer when the Antarctic is now partially attributed to being colder than the Arctic because it has an ozone hole, rather than an ozone dent, which the North Pole has. We want to reduce CO2, but increase ozone? To what degree, if at all, can increased CO2 compensate for decreased ozone? Or, why don’t we want to decrease ozone as well?
SA, did you watch the entire video?
I’m not. He isn’t.
In that video “energy production” means “production” of energy.
Not capture of solar energy. Not capture of wind energy.
The video is about the thermodynamics of using more energy than is available — by producing more — and how that can’t work out well.
He’s on your side. You should be on his side.
He’s making the point you want made — very clearly and bluntly.
#169–Yes, Chris, this is dealt with in *some* models. (There’s discussion of the topic in AR5, though I can’t point you to exactly the right spot just this moment.) To the best of my non-expert recollection, the answers to your last two questions are “Yes, probably” x 2.
#166–SA, you are sounding a tad cranky, though I appreciate the point you are making. The piece Hank was citing was, in part, a ‘reductio’ of the notion that unlimited growth is possible (let alone normal.) The ultimate punch line is that 2 millennia at an energy use growth rate of 2.3% pa would have us using as much energy as is emitted by all the stars in our galaxy.
However we sourced it, that would be way beyond ‘global warming’, unless we also had a magic waste heat sink.
In other words, the piece takes seriously a phrase you probably didn’t mean so–at least, not in the most literal reading of it: “more energy than we can possibly use…”
Hank at 168 quoted: “In winter, sea ice spreads over the ocean, creating an insulating layer, like a blanket, that prevents much heat from escaping from the ocean to warm the air. That means that the air above the ice can get bitterly cold—deep below freezing—while the water underneath remains much warmer—never getting colder than the freezing point.'”
Yes, but now that winter ice is much thinner and much more cracked apart and even slushy than before, so presumably more heat may be getting through even in winter, and so affecting things like polar vortex and other patterns. Over on Neven’s blog, people have noticed what they call WACC–Warm Arctic [Ocean anomalies] / Cold Continent [temperature anomalies], even in winter. That is mostly holding up this winter, especially with the cold over much of North America. (Note, though, that Europe has been quite warm lately, as has the Pacific side of Alaska.)
> wili … presumably more heat may be getting through
Let’s try looking it up, someone must have documents on that.
I’d guess that’s so (remembering that ‘heat’ there is water around freezing temperature, compared to air that’s much colder)
How would gas transfer from ocean to air correlate with temperature transfer from ocean to air? This looks at gas transfer increase where the ice is broken up: http://www.ocean-sci-discuss.net/10/1169/2013/osd-10-1169-2013.html
Metacomment — I’m trying to tempt one of you scientists who actually knows something about this to comment and teach us something here :-)
Hank Roberts wrote: “SA, did you watch the entire video?”
No, unfortunately I did not watch any of the video. I am rarely in a position to watch online videos. So mostly, all I can respond to is the text content of people’s comments and in linked pages.
I don’t really see the point in talking about, let alone worrying about, the problems of “waste heat” from burning ever-increasing amounts of fuel indefinitely, because that is not going to happen.
The energy available from sunlight every year is vastly greater than the energy available from all the world’s fossil fuel reserves combined. Readers may be interested in the PDF linked below:
http://www.asrc.cestm.albany.edu/perez/Kit/pdf/a-fundamental-look-at%20the-planetary-energy-reserves.pdf
As I said, contrary to popular belief, getting enough energy to power a technologically advanced civilization in perpetuity (or at least as long as the sun shines and the wind blows) is not a problem. It’s easy.
There are, of course, other constraints on “growth” (depending on how “growth” is defined) besides the energy supply. There are many “enviromental” and “natural resource” problems that humanity faces.
If we can solve the global warming problem quickly — which we certainly can do, IF we choose to do so — then we can buy the time to deal with those problems.
Re- Comment by Hank Roberts — 7 Jan 2014 @ 10:31 AM
You offer such a negative Vonnegut quote. How about something more uplifting and, perhaps, more appropriate:
“Every passing hour brings the Solar System forty three thousand miles closer to Globular Cluster M13 in Hercules — and still there are some misfits who insist that there is no such thing as progress.”
Steve
Some questions for climate scientists:
If C emissions proceed at rates given in “business as usual” scenarios, how much will the resulting warming prolong the current interglacial? If the continuation of fossil fuel extraction was limited only by resource depletion, will the climate system ever return to the ~100,000-year cycles established in the mid-Pleistocene? Or is there a threshold condition (e.g. loss of Greenland and/or Antarctic ice caps) that would be a point of no return?
These questions developed from some discussions with students, but this isn’t my field, so I’d appreciate any help addressing them. I presume that someone has been doing modelling work along these lines, so I’d be interested in any relevant references or links that I could share with students. Thanks for any leads!
If novice preceeds amateur then what preceeds amateur? Allow me to try my question again. I have heard said that the Clean Air Act accelerated global warming by removing, is it black carbon from the atmosphere. BC reflects sunlight to space decreasing global warming, aerosols trap infrared increasing global warming?
China and India are burning quantities of coal that far surpass the max coal America burnt. We know the CO2 traps heat. What is the net impact on global warming of CO2, aerosols, BC, sulphur, etc from the enormous quantity of coal now being burnt outside the developed nations. I expect auto/truck emissions and cooking fires should be considered also.
hank wrote: “Metacomment — I’m trying to tempt one of you scientists who actually knows something about this to comment and teach us something here :-)”
Hear here!
Hank and willi,
The basic impact of thinner sea ice stems from its multifaceted and temporal effects leading to the “Polar Vortex” weather. Kara , Greenland and Barents sea are not so covered, because the Arctic Ocean pack at minima was much reduced. Northwards bound Cyclones hugging this vastly more open water area penetrate fortress winter more frequently and inject vast amounts of heat straight to the Pole, reducing accretion and leaving sea ice thinner. Arctic Ocean thick multiyear ice is the foundation of winter and injects far less energy to the atmosphere than thinner ice, the later contributes many times more Long Wave Radiation from the sea than CO2 warming, sea ice thickness matters. An ideal Arctic ocean completely covered with 3 to 5 meters ice is not the same as Today’s ice pack. Further heat and water vapour injections from numerous leads are readily seen on IR pics from space. Reducing the strength of winter much further. The entire process is seen on surface level, with stronger inversions vanishing more readily, adding less resistance to Cyclones from the South, with their penetrations becoming more frequent , the Global circulation changes from the Pole Southwards.
Very good video compilation of scientific opinions
Yale: Climate, Jetstream and Polar Vortex
> Christopher Yaun
Have you looked at the page linked at the top left corner?
The one labeled Start Here
When you consider the size of the planet, and of the problems, the questions you raise aren’t going to be answered in a comment field on a blog, any blog — unless you want answers that are unrealistically oversimplified.
I recommend this advice, from a gun’totin’climate’nialist programmer, who was very smart about how people ought to ask -him- questions (even if he hasn’t used his own advice to learn about climate change)
How to ask questions the smart way
With complicated questions, the people willing to give you simple answers may not be your best resource, and the rest of us get tired of retyping frequently answered questions. As ESR writes, saying what you have already read and understood is a good way to encourage people to help you further.
You start your questions with “I have heard it said” — where did you hear or read the ideas you quote?
For example, the Clean Air Act — you can look it up — removed sulfates, at first. Sulfates reflect sunlight. There’s attention being paid to black carbon: http://epa.gov/region9/climatechange/blackcarbon/
You’re asking ‘how much’ for each of these forcings.
I’ve been liking this blog recently — others may comment on how well it answers questions, but he’s trying hard to give simple answers:
http://simpleclimate.wordpress.com/
Be very careful about trusting comments from strangers on blogs. Paste the claims they make into Google, and into Google Scholar — and compare the results. There’s a lot of fake science that comes up if you just google stuff.
I’m sure this is not a surprise to anyone at RC but still, the RW PR machine is in full gear. Did you know that you scientists have “total dominance of the media”?
“Do you know what the polar vortex is? Have you ever heard of it? Well, they just created it for this week,” he said. “They’re in the middle of a hoax, they’re perpetrating a hoax, but they’re relying on their total dominance of the media to lie to you each and every day about climate change and global warming.” ~ Rush Limbaugh
http://talkingpointsmemo.com/livewire/rush-limbaugh-media-created-polar-vortex-for-global-warming-hoax
For SA: https://physics.ucsd.edu/do-the-math/
Using physics and estimation to assess energy, growth, options—by Tom Murphy
Mr. Roberts, you wrote:
“…temperature transfer from ocean to air?”
Did you mean heat transfer ?
and if you don’t have time to read the blog, how about an excerpt:
Tom Murphy
and he speaks for many of the rest of us as well
Secular Animist–Below the link is text posted on YouTube with the video segment titled, “Tom Murphy: “The Fossil Fuel Joyride Is Over.”
Or, as I thought the first time I saw it: “We’re Not Even Taking Care of Our Gerbil Yet.”
His metaphor is: What makes us think we deserve a pony, when we aren’t taking care of our gerbil?
Along with finding that we have cloudy judgement about the fossil fuel joyride, he says we have no clear idea of what “sustainable” means or at what level we can expect to operate.
He says that we should be careful not to trivialize an unsolved problem, because it tends to reduce the imperative to work like mad on establishing adequate (renewables) capabilities in time–which requires decades of fore-thought and planning. (This is from his UCSD “Do the Math” blog, plus stuff on his own gerbil: his own domestic ventures with renewables.)
http://www.youtube.com/watch?v=HV0m6kbRDNI
Tom Murphy, associate physics professor at the University of California San Diego, projects energy needs for future generations to argue that current ways of living are unsustainable. Disputing the argument that technology can save humanity from a peak oil crisis, Murphy states, “the fossil fuel joyride that we have experienced has clouded our judgment.”…He currently leads a project to test General Relativity by bouncing laser pulses off of the reflectors left on the Moon by the Apollo astronauts, achieving one-millimeter range precision.
Murphy’s keen interest in energy topics began with his teaching a course on energy and the environment for non-science majors at UCSD. He has explored the quantitatively convincing case that our pursuit of an ever-bigger scale of life faces gigantic challenges and carries significant risks.
Hank,
Yes, I did think my example questions were rhetorical but would not be surprised if there were practical alternative ways of doing some things in our present societies that wouldn’t emit CO2 when they presently do. But the question is, is it realistic to expect to get to a zero carbon civilisation, without changing that civilisation drastically? Carbon emissions result from almost everything we do. Reducing emissions is one thing, stopping the increase in atmospheric carbon is another thing entirely.
Secular Animist,
“We are surrounded by vastly more energy than we can possibly use. We just need to convert it into useful forms.”
Could you expand on this and explain why that energy is not already in a useful form and not already being used for useful things?
Christopher Yaun @169 & @179.
I think you demonstrate your own predicament rather well @179. “If novice precedes amateur then what precedes amateur?” A trick question perhaps? Or is it posed by somebody who fails to see the level of complexity that their questioning engenders?
Asking how climate models account for things is different from asking about climatic impacts of aerosols, that is different from asking about the impacts from coal burning, that is different from asking about the effect of the location of those emissions. And that is not the total scope of your questioning. As Hank Roberts @183 points out, you ask far too much of a blog comment thread.
But if your questioning is taken in the round, I would offer the following responses.
[] Negative forcing from aerosols can only be playing a minor role in the “flatlining” or ‘hiatus’ as ‘non-flatlining’ global warming continues apace. The ‘hiatus’ phenomenon is actually rather restricted in its scope.
[] Global SO2 emissions are only about half from coal. (If you like a good read try Smith et al 2011 and if you like numbers try here) Emissions peaked in the 1970s and had fallen by some 25% by 2011 according to the work of Kilmont et al 2013
[] The main trend in recent decades has been a fall in emissions at high latitudes and a rise at low latitudes. There is the view that the effect of tropical emissions and European emissions would differ climatically, with perhaps tropical emissions having more force.
[] Black carbon emissions cause net warming through various mechanisms but my understanding is that globally SO2 cooling is considered to be greater although there remains a lot of uncertainty in this.
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/block.shtml
This is the National Weather Service Climate Prediction Center on “Blocking,” with description, and definition of the blocking index.
The first graphic shows especially strong Pacific blocking in the third week of December, if I am not mistaken.
#190–“Could you expand on this and explain why that energy is not already in a useful form and not already being used for useful things?”
Not directed to me, I know, and a big question. But I’d offer that one realistic aspect of the answer right now is that deep-pocketed corporate interests vested in legacy technologies are vigorously defending their energy oligopolies.
Renewables are emerging as significantly disruptive forces in a number of markets right now–including the US, where significant pushback is occurring in the area of two-way metering, which a number of companies have sought to eliminate or at least limit. If we were able to implement carbon taxes at the national level, it would, I think, be pretty decisive in this struggle. We’d see a whole lot more use of distributed solar–as may be happening in Australia, for example.
On another topic, I was reading a ‘viewpoints’ book on renewable energy, and was struck by an essay therein considering the merits of a hybrid renewable/nuclear system which basically used nuclear as a ‘battery’ by using nuclear-generated steam and renewable electricity during high-renewable-output periods to create biofuel at high efficiencies. Interesting, given that both liquid fuel needs and energy storage are important subtopics for a renewables-based energy economy…
But part of the scenario was the use of Solid Oxide Fuel Cells (SOFCs). Hadn’t paid much attention to the fuel cell industry lately, and when I did a little digging, I found that it’s made some strides since the ‘hype days’ early in the millennium:
http://www.cnbc.com/id/101077622
(In turn drawn from the corporate press page of Bloom Energy.)
http://www.bloomenergy.com/newsroom/media-coverage/
PS at 178 asked: “will the climate system ever return to the ~100,000-year [glaciation] cycles established in the mid-Pleistocene?”
I’m not a scientist, but I would be inclined to say “not any time soon” (tens of thousands to millions of years).
We are on track to go above 500 ppm in just the next few decades. That’s higher than CO2 levels ever were since the Antarctic ice sheet formed some 15 million years ago. And you can’t really have glaciation cycles without ice caps, as far as I know.
One place to look for further insight into your question would be the earlier loss of that ice sheet during the Oligocene, about 25 million years ago. It doesn’t look as though it took much of a CO2 push to make that happen then, but the various proxies disagree on how much added CO2 came into the system then. You can find some of the relevant graphs just by searching ‘oligocene CO2″ but there are doubtless more precise measurements in the scientific lit.
GIS is even more sensitive to temperature rises, so it is even less likely that GIS will come back any time in the foreseeable future. And keep in mind that CO2 levels/global temperatures have to come down and stay down well below the temperature levels at which they melted the ice caps to get them to freeze again (hysteresis and all that).
The problem with things like clathrate thawing being a slow process (if that’s what it turns out to be, as the various wise folks around here seem to think)–a process that takes thousands of years–is that it guarantees that there will be a steady added forcing of methane and CO2 for a very long time after human global industrial civilization has exited the stage (which it almost surely will do rather shortly, in the coming years to decades).
And of course if you push into time scales on the order of magnitude of tens to hundreds of millions of years, you have the issue of the sun slowly heating up to deal with. (But getting to that scale, you might want to check tectonic plate predictions to see if any new Himalayas are on track to be formed by then!)
(I’m sure others here have much more intelligent things to say on all this–just hoping something in my comments will be idiotic enough that it will prompt them to post a correction from their better-informed vantage point!)
patrick wrote: “Disputing the argument that technology can save humanity from a peak oil crisis, Murphy states, ‘the fossil fuel joyride that we have experienced has clouded our judgment’ …”
There is no reason whatsoever that “peak oil” — or more generally peak fossil fuel extraction, or more urgently the much more rapid elimination of all fossil fuel use that addressing AGW requires — should become a “crisis”.
All the energy so far consumed during our 150-year-long “fossil fuel joyride”, plus all the energy in the remaining fossil fuel reserves combined, is miniscule compared to the energy available on an ongoing basis from sunlight and wind. The idea that ending fossil fuel use will leave humanity without abundant energy, in a state of “energy poverty”, is nonsense.
As I wrote above, there are definitely material constraints on “growth” (again, depending on how “growth” is defined) — but the supply of energy is not one of them.
sidd, thanks for catching the typo.
> Tony Weddle
> is it realistic to expect to get to a zero carbon civilisation,
> without changing that civilisation drastically?
Another rhetorical question, eh? OK, I’ll play one more round.
Or as a doctor I know used to tell his patients:
I take it your position is rather
Tony Weddle asked: “But the question is, is it realistic to expect to get to a zero carbon civilisation, without changing that civilisation drastically?”
Yes, it is possible to get to a zero carbon civilization while improving civilization drastically.
#184–Re “Lush Rimbaugh comments”–wait, was that a typo? Anyway, rhetoric like that ain’t nothin’ (or should I have written in Cockneyese “nothink”?) but a big ol’ invitation to rhetorical hilarity. Swing for the fences, folks! That’s a hanging curveball, for sure.
To MAR at 191: “I think you demonstrate your own predicament rather well @179. “If novice precedes amateur then what precedes amateur?””
Meant to type,” if novice preceeds amatueur then what proceeds novice?” and by way of identifying myself as an amateur novice.