I have mixed feelings about nuclear energy. Part of my rational mind sometimes says maybe there’s a place for it in an interim energy mix before we shift to renewables. But my gut doesn’t like it at all. And my gut reaction is only strengthened by reading articles like this one in today’s Guardian, which outlines the potentially devastating impact of uranium mining on the Kalahari. (And explains that when the UK has tallied up the likely carbon footprint of its combined nuclear-coal-renewables strategy, it has completely excluded the carbon footprint associated with extracting and transporting the uranium that strategy will demand, much less its impact on the Namibian environment.)
Let’s not forget that the UK’s own Sustainable Development Commission carefully considered the virtues and disadvantages of nuclear energy, and recommended against it. Which means some hard questions need to be asked about why that government is proceeding against the advice of its own experts (though since it rather makes a habit of doing this, we must conclude that expert advice is solicited only in the hope that it will sometimes lend support to whatever policy has already been decided).
The problem with nuclear energy is that using it as an alternative to coal is a bit like switching to from heroin to methadone. It mitigates some of the damage associated with the addiction – without actually ending the addiction.
Until today, if you’d asked me why I consider nuclear energy to be unsustainable, even setting aside the problems of its carbon footprint and nuclear waste disposal, I would have said, well, the problem with nuclear is that it will allow us to continue a model of growth-based, energy intensive economic development which is disastrous in many other ways. It will fuel an economy which makes ever greater demands on other resources; with it, we will be able to postpone switching to a steady-state economy that acknowledges the strict limited water, land, biodiversity and other natural resources at our disposal.
Despite the fact that alternative economies are receiving very serious attention from very serious people, most can’t quite imagine any model other than grow, grow, grow.
But it seems there’s another argument against nuclear energy of which I was not aware. A slam-dunk argument engraved in the very laws of physics themselves: the second law of thermodynamics. Browsing through New Scientist this evening, I stumbled on an essay by the physicist Eric Chaisson of Tufts University, Massachusetts. In this article, he points out that human activity itself has a global warming effect, and that because of this, if populations and economies continue to develop along present lines, “the likely outcome is that a 3 degree C rise will occur in about 300 years, even if we manage to sequester all greenhouse gases”. ( A big “if”, I would say.) Here’s the abstract from his original paper, explaining why:
Even if civilization on Earth stops polluting the biosphere with greenhouse gases, humanity could eventually be awash in too much heat, namely, the dissipated heat by-product generated by any nonrenewable energy source. Apart from the Sun’s natural aging—which causes an approximately 1% luminosity rise for each 108 years and thus about 1°C increase in Earth’s surface temperature—well within 1000 years our technological society could find itself up against a fundamental limit to growth: an unavoidable global heating of roughly 3°C dictated solely by the second law of thermodynamics, a biogeophysical effect often ignored when estimating future planetary warming scenarios.
“Of course there is a way out,” writes Chaisson in New Scientist. “Renewables, which come directly or indirectly from solar energy, are already accounted for in the thermal balance of our planet and their use would not additionally heat Earth’s environment. Nor, incidentally, would energy derived from from solar-driven wind, water and waves.”
Chaisson’s insight, of course, also rules out nuclear fusion, one of the pet loves of the technological fantasists, as a viable future energy source. (“We can carry on destroying the planet using coal because soon we’ll be able to switch to destroying the planet with unlimited amounts of ‘clean’ fusion energy.”) My reasonably educated guess is that it would also rule out space-based solar energy (beaming electricity down from satellites). I am not sure what might be the implications for the use of geothermal energy; my suspicion is, not good.