The Forecast in the Streets

In the “severe” scenario, the globe warms by 2.6 °C by 2040 and sea level rises about a half a meter. Scientists in 2040 conclude that the eventual collapse of Greenland and the West Antarctic ice sheets has become inevitable in the centuries that follow. Agricultural production declines in the arid subtropics and in increasingly flooded river deltas. Again to pick a random example from the report: the river systems in the American Southwest collapse, leading to impoverishment of Northern Mexico and increased migration pressure in the U.S. Resource stress in Latin American leads to a tendency toward populist, Chavez-type governments, and more extensive regions of de facto anarchy such as found today in parts of Colombia.

The “catastrophic” scenario assumes positive feedbacks in the carbon cycle to warm the planet by 5.6 °C by the year 2100, and sea level has risen by 2 meters. I feel compelled to note that if this is supposed to be a worst-case scenario, I personally can imagine worse in terms of sea level rise. In the social realm the crystal ball gets murkier as the report progresses from expected to severe to catastrophic, but one important ingredient in the prognosis for the catastrophic scenario is the migration of millions of people, a scale unprecedented in human history, potentially enough to undermine the stability of civilized governance. One participant recommended that we check out the movie Mad Max, only imagine it hotter.

There is far too much in this report for any sort of summary really to cover, and anyway I’m a techie rather than a touchie so my retread wouldn’t do the original report justice, but you get the idea. Results from the IPCC are summarized clearly, including regional climate projections, but the point is also made and discussed that climate forecasts tend to be in general conservative. In the arenas in which I have some competence to assess, the judgments the authors have made seem measured and fair to me. The report is authoritative and very meaty, bringing an astonishing array of perspectives and insights to the table. One could read this report and nothing else, and come away with a considerable expertise on the potential impacts of climate change. I highly recommend it to the readership of realclimate, and I look forward to reading your comments.

Thanks to Hank Roberts for digging this up.

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363 comments on this post.
  1. dhogaza:

    agree wholeheartedly. dhogaza and I seem to have got hung up on an irrelevance (ie. harvesting).

    Um, I was trying to point out WHY it’s irrelevant. When you brought it up, it wasn’t at all clear you thought it was irrelevant. “adding back those harvested numbers might lead to a 33% increase in population …”. That’s hardly a statement that supports an interpretation of “irrelevant”.

    However, their name is used in vain so often and it is baldly stated time and again that they face “extirpation” that even a “we don’t know” position draws shrill accusations of denialism, etc, etc

    If we lose the artic ice cap, they’ll disappear.

    I challenge you to find a single biologist who’s studied polar bears who disagrees with that statement.

    How, then, do they not “face extirpation”?

    A key premise of this paper is that GCMs are “not valid as a forecasting method” with which you may take issue but again, the papers explain exactly why they believe this to be the case.

    If this is true, then I guess we can safely ignore model predictions for everything, right? Not just polar bear future population levels?

  2. John Mashey:

    All (of us) old farmboys know how much hard labor it is, which is why many of us didn’t want to be farmers. Farmers are only 2-3% of the population in the US, so they grow enough to feed a lot of people and even make enough meony to live first-world lives, neither of which works very well for subsistence farmers, in countries where 50-60% of the population farm.

    But as a whole, North American farming is highly dependent on:
    a) Nitrogen-based fertilizer, i.e., from natural gas.
    b) Cheap petroleum, to get fertilizer and other inputs to the farms
    c) Cheap petroleum, for mobile farm machinery
    d) Cheap petroleum, for trucks/rail/ships to get food to wherever its going
    e) Energy for pumping water

    Big, productive mid-West farms put a lot of small Eastern farms out of business, among other things, letting some land go back to forest.

    a) Minimizing use of nitrogen is a good idea (less N2O).
    b), c), and d) some of this can be electrified. Small/medium electric tractors already exist, and tractors don’t usually need to go far from home, so some don’t even need to be hybrids.

    I’ve yet to see existence proofs for electric-only combines, or big tractors, or Class 8 trucks – so far, battery energy density just isn’t high enough, and the usage characteristics of cars that make electric and/or hybrids work don’t apply so well. Maybe fuel cells, maybe hydrogen? A lot of breakthroughs are needed for those to work here.

    For the parts of b), c), d) that are not cost-effectively electrified, and assuming that we first go after all the efficiency-engineering we can, I haven’t yet seen convincing overall systems approaches that don’t include *some* biofuels, whether those are second/third/fourth generation cellulosic ethanol, biodiesel, butanol, whatever. Unlike a lot of car driving that is truly optional, crops *must* be harvested, and *must* be gotten to customers, and crops weight what they weigh, and making vehicles lighter helps, but not as much as for cars. I’d be happy to see everything be electric, but I just don’t see how to do it.

    If not biofuels, there will be huge pressure for more oil sands, shale oil, coal-to-liquid, and cutting down Eastern forests a third time to get more farms closer to NYC, Boston, etc.

    Q: Why do Old Amish “waste” pasture and feed on horses? Why don’t they just have crops and cows?
    A: they can’t use tractors, so they need horses for farming and transport, and spending some land on horses increases their overall yields over what they could do by hand.

    It does no good to grow crops and leave them rot in the fields, which means that some of the fields are likely to grow well-optimized fuel crops, i.e., not corn in the long run.

  3. Hank Roberts:

    JCH, don’t stop thinking about tomorrow.
    Don’t we have a killfile here?

  4. SecularAnimist:

    John Mashey: “… cutting down Eastern forests a third time to get more farms closer to NYC, Boston, etc. …”

    A better idea would be to re-agriculturalize the suburbs. There are huge amounts of land available throughout the East coast suburban sprawl that could be converted to food production. Farming may be “hard labor” but many thousands of people practice highly productive, intensive organic vegetable growing as a form of recreation. Millions more devote considerable labor and large amounts of money into maintaining extensive decorative plantings, eg. lawns, which could easily be redirected to food production.

    During the World War II era, so-called “victory gardens” made a significant contribution to the nation’s food supply. Following the cutoff of a cheap fossil fuel supply from the collapsed Soviet Union, Cuba successfully fostered organic urban agriculture as the backbone of that country’s food supply.

    Clearly we need to reduce the greenhouse gas emissions and other environmental harms associated with US agriculture, and end its reliance on soon-to-be scarce & expensive fossil fuels. One way to accomplish that is to turn the sprawling suburbs into “greenbelts” that produce large quantities of a variety of high-quality organic foods right in the midst of our large population centers.

  5. Jerry Toman:


    Apparently we are able to get water out to a field for irrigation without extensive duct building by using the “pivot point” concept which allows efficient spreading of water over the field.

    Why can’t the same concept be used to distribute electric power to tractors or combines so they won’t need to rely on batteries with their tedious and inefficient charging cycles and their inherent “dead weight”?

  6. JCH:

    A killfile would be a good place for the misplaced notion that human and animal power should be ruled out as possible solutions for a more CO2 friendly means of food production in the future.

  7. Barton Paul Levenson:

    I have Crohn’s Disease, and sleep apnea, and a third condition I won’t specify, all of which have tiredness as a side effect. As a result, I am much more feeble than a normal person my age. I don’t think I could cultivate a flower garden, let alone the two acres or so of crops I’d need to feed my wife and myself. Home food cultivation might help decrease energy needs, but some people, like me, couldn’t handle it, and I’ll bet a lot more would rebel at the sheer labor involved. This is the kind of thing deniers will jump on with a vengeance to prove that AGW folk want us to go back to a more primitive lifestyle. Find another solution, please.

  8. Hank Roberts:

    Jerry, interesting idea, though center-pivot irrigation is I think used only on flat fields

    I wonder if no-till agriculture can be done in a circular-radial plan on slopes?

    Planting along contours is the standard for reducing soil loss, and that’d be harder to handle.

    Anyhow, as others have noted, diesels that work at a steady speed are much more efficient than internal combustion used to accelerate/slow/accelerate or stop and start as for passenger vehicles.

    I know also that at least big diesels go 100k miles between major overhauls — that’s why cities still run diesel buses half empty, they still cost much less than using small passenger vans on the same route overall.

    Cleaning up diesel is obviously happening fast for a lot of reasons, which can extend use of those engines, and they do run on vegetable oil even without modification as long as there’s a battery heater to melt it if it congeals overnight in cold weather.

  9. george:

    Barton (357), no one expects you to grow your own food in your back yard. No one would force you to even if you were in perfect health. However, if you lived in my neighbourhood, I would be pleased to grow quite a lot of your food for you: you could buy it from me rather than the supermarket. I’d even deliver. I already do this, with twenty or so seasonal vegetables, for a cafe and a number of families in my community. What’s more, I grow organically and by hand, releasing no hydrocarbon CO2 (other than in delivery). I get paid, per hour, about as well as with my other jobs and I find it an awful lot more enjoyable and satisfying than staring at a computer screen. There’s probably somebody in your neighbourhood doing the same…

  10. JCH:

    Each center pivot usually represents a water well that is drilled deep into the ground. In Nebraska they do operate on rolling terrain as many of them are powered by electricity.

  11. SecularAnimist:

    Barton Paul Levenson wrote: “I don’t think I could cultivate a flower garden, let alone the two acres or so of crops I’d need to feed my wife and myself. Home food cultivation might help decrease energy needs, but some people, like me, couldn’t handle it, and I’ll bet a lot more would rebel at the sheer labor involved.”

    george replied: “However, if you lived in my neighbourhood, I would be pleased to grow quite a lot of your food for you: you could buy it from me rather than the supermarket. I’d even deliver.”

    Barton, if you don’t happen to live in george’s neighborhood, then most likely there are farmers markets and/or community supported agriculture (CSA) farmers in your neighborhood, where you can purchase locally-grown food that is either organically produced or at least uses far less petrochemicals and energy to grow and deliver than the factory-farmed stuff that is hauled in to supermarkets from 3000 miles away in refrigerated deisel trucks.

    I think the transition to a mostly locally- and organically-produced, mostly vegetarian food supply will be inevitable as a result of increasing energy prices and then energy scarcity in the post-peak oil era. As with other impacts of the impending decline in cheap fossil fuel supplies, it can certainly help with the global warming problem if we move in that direction by choice sooner, rather than later when forced to. And indeed, farmers markets and CSA agriculture are proliferating. And the food produced this way is MUCH better, so eating this way is in no way a hardship.

    By the way, in his 1982 book Survival Gardening, author John Freeman wrote that by using the intensive raised bed organic growing techniques pioneered by John Jeavons (author of the classic book How To Grow More Vegetables than you ever thought possible on less land than you can imagine), and growing specific vegetable crops selected for maximum nutritional and caloric yield, it would be possible to produce sufficient calories for one person to survive from only 1,000 square feet of cultivated land. It should certainly take far less than an acre of land to produce all the food needed for one person to eat very well … unless you are planning to graze cattle.

  12. John.J.R.P.:

    Hi ALL, if your interested in a different way of growing things,and food to eat, and the 3 Rs please take a look at my website to do with, New Recycling-Reuse of Waste Ideas, which I’ve posted about on most of the gardening websites in the UK, and it’s to with trying to save lives too, for next to nothing which you might like to tell others about, on my behalf, if your interested in any of these things, like I have been for most of my life. Thank you.
    May you and yours and what you grow live long and happy. John.J.R.P.

  13. Jerry Toman:

    Thanks for your comment, Hank.

    The purpose of this, as well of several of my past posts, has been to present the idea that electricity can play a lot bigger role in mitigating the effects of (imminent) peak fuels (gasoline, diesel, NG) than is generally believed.

    It can also play a role in the making the production of fertilizers and even biofuels (boo!) more economic as I’ll explain in more detail in a later post. These can be used to maintain food production, supplemented by the “electric tractor” example I gave above.

    Cheap electicity allows us to extend the range of its most important quality with respect to agricultural production, its ability to motivate the pumping of water from ever deeper reservoirs or longer distances.

    Having a method to produce cheap electricity from renewables, allows us to mitigate the effects of natural gas depletion because it allow us to convert our homes (hopefully with common walls, ceilings, etc) from furnaces to heat pumps and, more directly, eliminate the need to burn NG to produce electricity.

    So I’m not posting here simply to “stir the pot” when I mention the Atmospheric Vortex Engine which, IMO, has the potential to produce this cheap electricity. This is deadly serious for everyone in the world, and therefore, if I can get any feedback (a term everyone here is fond of using) with regard to its potential, hopefully leading to some consensus, I would be grateful.

    As of yet, I haven’t received a single reason, based on “scientific” analysis that would indicate that the concept “can’t work” belying Prof. Nilton Renno’s comment that the science behind it is “solid”. If this is true, then the weight of opinion of the RC Team, perhaps given as an “Endorsement” (at recommending further development (not a guarantee), given at the AVEtec website would go a long way toward convincing people to pony up the funding necessary to move foreward.

    On the other hand, if anyone knows a patriotic “angel” willing to fund it, I suppose all that wouldn’t be necessary.