and I can't see anything unreasonable in your hypotheses. Thanks for ruining my day.

(nice work)

Wish I was brilliant enough to find something here to argue with, but am not sure, even IF I was smarter that I could find any serious holes in your reasoning. Alas, well done, Glider Guider. Would that the Powers That Be and The Great Unwashed were listening. Ms Bigmack

I mean, yes, maybe we'd be able to colonize Antarctica and Greenland. I question whether anything closer to the equator would remain habitable by megafauna such as us.

+10C is way out in the middle of beyond-a-doubt rapid mass extinction country.

We'll make it.

We have no idea if we will even keep our technological growth rate up during this ecological disaster. Further, if we can't fix this, it surely can't be cost-effective to colonize a planet without an atmosphere. Mankind would be better off building domes here.

Off-planet colonization has been a techno-optimist shibboleth since the early days of space exploration. I we want to live under domes in an inhospitable, resource-poor environment, why not use the one we'll already have at hand? Perhaps the answer is that the idea is less romantic - it feels like desperate survivalism instead of diaspora, an admission of defeat rather than a promise to the future.

The technology to recycle ones waste and provide life support on an inhospitable Earth would also be useful for Mars, the moon, asteroids, etc.

I'm more concerned that we might fuck up the geoengineering and cause a Snowball Earth than I am about us actually hitting 10C. We're not just going to sit around and do nothing about it, but the solution we're going to chose is a big gamble.

Technology is an amazing thing.

A lot of people are going to die though. Big time.

Organization, and energy. It's actually a recursive fractal situation, because energy itself requires technology - and so requires organization and energy.

I think organization on the scale required to maintain high technology may be one of the first casualties. That's why I'm against the introduction of any more nuclear power, and why I'm fundamentally pessimistic about technological "solutions" in general. I don't think we'll get back to the Moon for example, at least not for more than one grand gesture, one final curse flung into the face of God as the darkness closes in.

How much longer would they last if 6 billion people die off?

With a billion people left, how much of a hit do those industries take? And the university systems that support all the engineering training, and the ancillary industries that design and manufacture the seismographs and computers and mining equipment? There is a critical mass of organization that needs to stay up for the whole edifice to function. Colour me skeptical.

As I conceded on several occasions I can't rule out a scenario where the die off is utterly devastating, it's just that I don't have evidence to believe that to be the case. As far as I see it, there's no way even the most corrupt organizations are going to let it get so bad as to do absolutely nothing. The 10C number is conditioned entirely on no albedo actions being taken.

As David Keith points out, as soon as Asia is hit hard by long term seasonal monsoon disintegration they will be desperate and they will start spraying aerosols rather quickly. This will happen no more than 20 years from now given the rapid increase in feedback effects.

Hell, the US may do it sooner than that if the current exceptional drought continues.

The next 20 years are going to be pretty surprising, one way or another.

Or, if they are, why do they ignore what's going down?
Good work GG. Excellent post. Keep it up. Maybe the message will get through by osmosis.

If they realize nothing can be done about it within the structural context that they have to deal with, perhaps they have made decisions to just carry on. What would you or I do if we had the "national leadership gene" and this knowledge? I don't know for sure, but I might decide that telling everyone they're screwed might not be such a bright idea.

A few may be starting to see the light, but still prefer to err on the side of hoping it will fix itself if we build enough windmills.

"Getting it" requires scientific curiosity and atithmetic, after all. Both skills are known to be in short supply amongst politicians.

in the third to last paragraph of your post.

If we indeed do reach 4*C by mid century I feel this will greatly limit our ability to maintain the social and industrial order necessary, to rapidly burn off the rest of the hydrocarbons in the last half of the century. Therefore, what we already have baked in the CO2 concentration mix, will be about it. What is the planet's sensitivity to doubling CO2, who knows? But what we have seen at just .8*C rise, are undeniable feedbacks much ahead of the IPCC models' schedule.

Hurricane Sandy, before that Katrina and others, already show large disruption in large cities and commerce. 2011 and 2012 saw major drought on five continents, and subsequent crop failures. The Arctic ice melt guarantees continued and larger disruption of sea and atmospheric currents, leaving weather models useless for planning agriculture. This is all happening at .8*C.

At 2*C there will be far more disruption, and in addition almost certain fresh water restraints. Will these disruptions be linear in proportion, or exponential? At 4*C I think we will be very lucky to have much order remaining, starvation and nomadic migration will add stresses of their own. At this point I foresee industrial output chaotic at best, limited by the abilities of consumers as well as water and power considerations. There will still be plenty of hydrocarbons for power production, but I question seriously if the infrastructure and social order will remain at levels needed to continue rising production.

In short, I don't think it likely we have at our means the innovation necessary to adapt to 2*C then 4*C in an already faltering economy, climate, and society. On a global level, that would take cooperation and sharing of resource and intellectual property. Hasn't happened in the last 5,000 years, and I don't expect it to start now.

I also think anything more than 4*C is moot in the long run, as that bakes in 6*C minimum with chances of unknown feedbacks as well. And I don't agree with some that believe anywhere beyond 4*C is adaptable. It is easy to say PETM was survivable to most mammalian species, at 6*C, but how many died, how far did they have to migrate, and were they as fragile as humans in cold and warm conditions? What were the conditions of the earth before, PETM, pristine? What other land mammals except humans have depended on the oceans for a large amount of their sustenance? No, I can't image much above 4*C as survivable, with the variance in heat conditions in different latitudes.

Just a few of my thoughts. hrh

For me much of the uncertainty lies in how fast the heating follows the CO2 rise, how the instability manifests itself and of course how we respond - first as nations, then as a global civilization as things begin to come apart. As long as this globalized, industrialized culture remains intact I share your pessimism about the probability of cooperative, altruistic action.

I personally think we have few options left any more for dealing with this - we seem to have +4 baked in the cake at this point, and the effects of rising temperature seem so far to be worse than we expected, as you point out. If we don't lose the fight around mid-century, I think we'll probably just lose it more deeply and surely later on.

I'm now pretty much convinced of the possibility of the extinction (or virtual extinction) of our species some time next century, as the planet finally turns inhospitable to us. The time between now and then will be filled with intensifying foreshocks of that existential earthquake.

Or basically just preparing to sit back and watch the show go down?

Im fairly young with a family. From one day to the next, its difficult to figure out what I should be doing and caring about. Each day that comes I embrace it these days, especially when I head outdoors. But by no means do I truly have the capital and time to build resilience in this world (another reason I am frustrated at the government refusal to aid communities to build their own). I simply have my head spinning most of the time, losing motivation to participate in the conventional economy...but seeing some futility in building a local, unconventional one. One day Ill have to tell me children about the world. I don't know if I will have to explain to them why they are hungry one day.

It's easier for me because I'm over 60 and have no children. If I had kids I don't know what I'd do.

Just ask those folks (though none would remember now) what happens when you have an island ecology and somehow manage to destroy it.

Apparently, you wage unlimited war on one another, topple your godheads, and then proceed to eat each other. Ooooh. Maybe that's the zombie apocalypse? Hehe.

ideas about what happened at Rapa Nui which are consistant with what was going on around the world then. National Geographic's special on them was terrific.

Has been so for years. I follow it rather closely but my mind isn't set. It's a good tragedy of the commons parable though, don't you think?

Plus, if the max pop was 3k, doesn't it seem unlikely that the Moai ancestor carvings in such large numbers would have appeared during a 200 year window?

Plus, European colonists introduced the specific species of rat all over the pacific and beyond and yet you don't see this sort of devastation typically? Perhaps a lack of natural predators in this case? That seems to be Hunt's opinion and he's probably right.

I think a comparative study is in order on this one. The whole thing might have been a confluence of anthro and non-anthro events.

Local oral tradition doesn't support Hunt's claims, the French accounts don't support Hunts claims. All they've got is the radiocarbon dating which changes settlement dates by 50 years. Either way, we pretty much know the place was covered with palm trees in 1100 a.d. So what happened to them? Rats? Humans? Both? Alien plasma weapons when one of the carvings didn't look enough like The Supreme Divine Galactic Emperor Xarxagogo XVIII? For the parable's purpose, it doesn't matter. Unless you believe the population of humans was always 3k and never 15k. Frankly, I don't buy that. Three thousand people didn't spend their time lugging around those damn statues and still feed and clothe themselves. Horse manure.

by any stretch. Where once being taken for slaves and introduced disease devastated, now Chile is trying to wipe them off the face of the earth. Or so it appears.

Rapa Nui peoples' language is so close to ours we can make out a lot of a conversation.

To anyone who read my last post differently than it reads now, e kala mai!
yikes.

Since they never published it in a peer review paper.

Then I say its bunk. No peer review, no dice. I didn't know they didn't publish. The fact that they didn't publish automatically destroys their credibility in my eyes - and NatGeo apparently sucks now too if they're even going to substantiate that. History channel syndrome.

They are completely wrong in every way. National Geographic got duped.

They base their entire premise on a later arrival of the inhabitants, a basis which is not supported by their "work" since they ... haven't published it. It flies in the face of the rest of the evidence, and they even have to pull out an "outlier" and implausible explanation for the deforestation (rats, which don't affect the other islands in that region in that way), in fact there were previous studies which showed that rats wouldn't have that effect, yet they chose not to even cite the paper.

Classic denialist approach. Cite the evidence you want (and even evidence you don't have), then when there's evidence to refute it, ignore it. For example, the protracted wars between the inhabitants are well established, hundreds of skeletons show damage, but they chose to cite an old outdated report where someone said there was no evidence of that kind of thing.

Here is a sufficient enough refutation of the authors works.

They wanted to paint a contrary narrative, and they didn't do the science to back it up, so they weaseled, that's what I see anyhow.

thanks for your thoughts.

he's one of the people here that I listen to very carefully. Has pretty much all his shit in one bag, that boy.

about our ability to keep on keeping on in the face of very bad weather. You can't get a crop without water. There are water shortages all over the World. Water will be in critically short supply long before 2100. I admire your effort to find a silver lining, but I keep thinking about those population curves Caton used in Dieback.

What happens when we hit about +2 to +3 or so. Not to the weather - we know that's going to go to shit - but how we decide to respond. We don't have to wait for +4 or +6 for things to grab out attention, 2 or 3 will do that well enough. That will probably happen around 2040 or 2050. Unfortunately if we hit +2 we'll still have another 3 in the pipeline, that will only manifest in the following 30 years.

This is the problem - by the time we decide to react and stop all further fossil fuel use, we still have at least half the eventual warming still to come. Take out current situation: we have +0.8C visible, and everybody assumes there is another half-degree or so to come. But if we all stood still and held our breath right now, it will probably go up to +2 over the coming few decades. The hysteresis is the killer - it makes everything we do too late by a bunch of decades.

I just think it's going to happen sooner than expected. One feature of collapse is acceleration.

We've seen it in virtually every aspect of this unfolding clusterfuck so far. That's why I don't feel too bad about posting threads like this. My projections may seem like they're be on the upper bound of the possible - right now. We're learning that even pessimistic predictions may be overtaken by events, though.

stops play.

I doubt things will get quite THAT warm. I'm expecting a 4-6C warming depending how fast we act.

Then again, I'm the kind of techno optimist who drives you nuts.

2300 or even 2200, if it isn't stopped? That may not be so far-fetched.

However, though, I can say with a fair degree of certainty, that while the worst-case scenario(that is, 6-7*C by 2100 if most or all feedbacks play out to their worst possible extent)is by no means impossible, it's also not inevitable by any stretch. 3-4*C seems to be the average I've seen so far and while that would present many unfortunate challenges for humanity, it wouldn't necessarily spell the total end of civilization as we know it(although certainly, many things would have to change).

Hysteresis is not our friend.

And +6 is close to PETM territory anyway. We don't need +10 to put a whammy on us.

Last edited Tue Nov 20, 2012, 01:46 PM - Edit history (1)

The biggest question is what happens in the next 30 years. We're on the steepest part of the global emissions curve so far. At the rate we've been increasing our emissions since 1985, they could rise over 60% to over 55 GtCO2/year by 2030, and potentially to 75 Gt/year by 2040. That would raise levels to over 500 ppm by 2040.

I just don't see us reining in our emissions substantially - if at all - before 2040. I think we might be able to slow the rise of CO2 levels starting in 2040 to 2050 based on a combination of panic-driven policy changes and global economic depression, so that we end the century at at around 700 ppm. That would imply a rise of about +5C by the end of the century.

If CO2 emissions then fell to zero in the first half of the 22nd century, we would probably see a rise to +12 by the end of that century. They would rise that high because of both the additional CO2 we would generate in the first half of the century, as well as the long feedback effects that Hansen et al think raise the final equilibrium climate sensitivity to +6C per doubling.

+12 C is bad, but if the action we take by 2050 isn't drastic enough, we won't be able to keep it to even that level. We are in a very, very serious box.

Thanks for correction.