Categories

A sample text widget

Etiam pulvinar consectetur dolor sed malesuada. Ut convallis euismod dolor nec pretium. Nunc ut tristique massa.

Nam sodales mi vitae dolor ullamcorper et vulputate enim accumsan. Morbi orci magna, tincidunt vitae molestie nec, molestie at mi. Nulla nulla lorem, suscipit in posuere in, interdum non magna.

Climate change migrants

It is quite possible than climate change will close down whole regions or countries on the planet. The process has started in northern Kenya already. Forecasts are, that by 2050, 200-700 million people will be forced to move to escape the impacts of climate change

Many of these migrants will be shifting from rural to urban areas placing greater pressure on an urbanisation process that is forecast to accelerate in intensity regardless of climate change. At the end of 2008 one half of the world’s population lived in cities. By 2050 that figure will have increased to more than two-thirds.

3 comments to Climate change migrants

  • John Mashey

    This might be a problem:

    1) Most food is grown in rural areas.

    2) Farmers:
    a) A farmer with minimal energy (not even draught animals) is poor.

    b) A farmer with more energy (say, some teams of horses), they can actually live OK. Consider the Old Order Amish (no gasoline or electricity, although 8th-grade educations and ~7 kids/ family is not for everyone.
    Still a huge chunk of the world’s population would trade lives with them in an instant.

    c) A farmer with a 300HP combine, fuel, electricity, and access to rail+roads can farm hundreds of acres, and may even be able to take a vacation now and then. But this takes energy. If one looks at the states of the US, as per state facts, one finds that some areas (like New England, NYC) simply do not grow much of their own food, and unsurprisingly, these are more urbanized.

    In the USA, ~2% are farmers, and grow more than enough food. In 1900, it was ~40%.

    In any case, if one is dealing with irrigated land, there is energy cost in getting water to the right places, assuming there is water somewhere around, and of course, AGW is going to move some of that water into less convenient places.

    Also, nitrogen fertilizer is most commonly made with natural gas.

    3) I’d claim that modern urbanization is enabled by having enough energy to let

    a) Farmers raise enough extra food to feed others
    and
    b) Ship it from where it’s grown to the cities

    [This is certainly where European-style countrysides have some advantage over the rest of us.]

    4) Even ignoring climate issues, Peak Oil is already ~here, and the one-time capital of fossil fuels will have been pretty much spent by 2100. Adding climate change, we have to taper that down much faster. Hopefully,m we’ll invest enough energy capital to build energy-income assets.

    To be honest, it is totally unclear to me how the world population can get 2/3 urban, and substantially bigger in an energy-constrained environment…

  • hc

    All good points, as usual, John.

    One minor advantage in having people shift to cities is that their carbon emission behaviour as electricity and transport fuel users can be more easily micro-managed.

    But in all other senses it seems to me that, as you point out, energy-intensive agriculture will be stretched beyond the point of possible scale economies and efficiencies from farm-rationalisation that in the past facilitated urbanisation.

  • John Mashey

    Re: cities and energy/transport efficiency

    Thanks.

    I’m certainly no expert on this one, but maybe economists interested in transport & such might be, and might even recommend some good studies:

    Summary: in an energy-constrained world, given the existing built environment, what are the best mixes of city, suburbia, and rural dwellings, transport patterns, and other buildings?

    I’ve had several discussions, typically with dense-urban dwellers (esp. Boston, New York, Washington, DC) that I might summarize together as:

    a) Cities are good because they are energy-efficient.
    b) Suburbs [of the N.America/Oz flavor) are truly awful for energy efficiency.
    c) Small towns then aren’t discussed.

    So, we ought to build up a) and tear down b).

    My response is: so, if everyone moves to dense cities, who is growing the food, and where? Does this get to be like Eloi & Morlocks? It seems that many people have relatively little knowledge of farm areas and how food gets to them. In the SF Bay Area, people are trying very hard to redensify decades of cheap-oil-urban sprawl, and it’s not easy.

    In an energy-constrained world, some things are unclear to me:

    1) Constructing really high-density cities [I think of Manhattan, Honk Kong] is not cheap. When I was at Bell Labs, we had 3 kinds of planning areas:

    a) Rural
    b) Urban/suburban
    c) Manhattan [all by itself, because nothing else was really like that]

    So, I don’t know how much it costs to build and maintain cities, even though local transport is easier.

    2) Large condo/apartment buildings are certainly cheaper to heat and light, partly because they are smaller, partly because they have more shared walls and floors, and sometimes because efficient CHP is available. On the other hand, in some places, Urban Heat island doesn’t help

    3) But, like the food, if one is in the middle of a big city, important things come usually from elsewhere:

    – food, almost certainly
    – water (sometimes, and sometimes with much pumping … 20% of CA’s electricity)
    – fuel
    – electrical power (often)

    Do the energy costs of those things and their transport get counted?

    As a simple example, I live in a town that looks very rural (horse farms, open spaces, trails, woods) just uphill from Stanford, i.e., moderately low-density, long-established suburbia with minimal public transport.

    We recently had a new grocery open 10 minutes’ walk from our house. In local “climate task force” meetings, we were thrilled, because it meant less trips for people to go further. We even tried to model that for carbon footprint. But, it’s hard, because there are also more big delivery trucks coming up the road. Maybe we’d be better driving a little further down the road and buying from the local farmers’ market. Suppose we all had electric cars … but the delivery trucks weren’t…

    4) In some places in suburbs or rural areas, one *could*
    – be less distant from where (some) food is grown.
    – have a well, or easy access to fresh water from rivers.
    – (fuel is hard, unless reasonable biofuels ever work, but hen electricity…)
    – be net-zero-electricity with solar panels on a single-family home, in some places [like here]. Around here, people are going all-out for electric cars, PHEVs, charging stations (Coulomb Technologies). That combination might keep suburbs (at least close-in ones) reasonably practical, especially if one can use a bicycle or small electric to get to train stations.

    Maybe it’s possible to get to NZE in a big city, but it seems hard, especially with skyscrapers and shadows.

    Anyway, my general concern is the extent to which policy can be guided by studies that are careful not to draw a line around an area, optimize within it, and ignore what’s going on outside to support what’s inside.