The Climate in Emergency

A weekly blog on science, news, and ideas related to climate change


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Solutions that Aren’t

Occasionally, we hear nuclear power, natural gas, or even cold fusion advanced as solutions–or at least partial solutions–to the climate crisis. It is true that each of these has the potential to give us energy with much lower greenhouse gas emissions than coal or petroleum products. It’s also true that each has obvious drawbacks–existing forms of nuclear power plant blow up occasionally, natural gas is fracking awful, and cold fusion might not even exist. But, proponents assure us, all these are surmountable problems and we shouldn’t hesitate to use all available tools when the climate is on the line.

Yes, I’m being flippant on purpose.

But as obvious as the drawbacks are, the argument for giving all available options a try does have a certain merit; the drowning should not question the life-preserver, after all. As usual, a little bit of knowledge is dangerous, because it allows two conflicting arguments to each be framed in terms that appear to make complete sense.  That’s why I want to go into detail about all the various reasons why these solutions aren’t really solutions at all–and what the real solution is.

Nuclear Power

Yes, nuclear power plants–technically, nuclear fission plants, because their energy comes from atomic nuclei breaking apart–do sometimes blow up. They don’t do so very often, so there is an argument to be made that the small risk of catastrophic failure is worth the certainty of low-carbon energy. The counter-argument is that even a small risk of catastrophe is too high. We can leave that debate to philosophers, because even a perfectly functioning nuclear power plant produces radioactive waste that nobody really knows what to do with. In other words, there’s going to be a disaster even if the plant functions perfectly–it will just be a slower and less dramatic disaster.

Perhaps more importantly for this discussion, nuclear power isn’t free of greenhouse gas emissions. While it’s true that a plant in operation produces only heat, steam, and nuclear waste (the steam spins turbines, generating electricity), virtually every other step in the process, from mining uranium to building and eventually de-commissioning the plant, releases greenhouse gasses. Estimates of how much nuclear power plants actually add to the greenhouse effect vary a lot,  though the extremes on either side suffer from clear methodological problems. 66 grams of carbon dioxide equivalent per kilowatt hour (gCO2e/kWh) is a reasonable, middle of the road figure. That’s about a tenth of fossil fuel alternatives, but it’s not nothing.

True, as long as fossil fuels power most industry and transportation no power installation of any type is greenhouse-free, but wind farms only have about 10 gCO2e/kWh. That’s one sixth of nuclear’s figure, and wind farms  never blow up.

And on top from the shortcomings nuclear has in the abstract, the practical limitations of the real world create two more serious problems. First, uranium, like fossil fuel, is not a renewable resource. Eventually, we’ll run out of it. As supplies start to run low, the nuclear industry would find itself in the same position the fossil fuel industry is now–forced to exploit ores of poorer quality or that are harder to get to.  The harder ore is to mine, and the more ore must be processed for the same amount of energy, the higher the carbon footprint of nuclear power will be.

Second, switching from fossil fuel to nuclear fission would involve building a lot more nuclear power plants., something like a new plant every week for decades on end. Since 12% of a nuclear plant’s carbon emissions come from its construction alone (not counting mining and processing its initial supply of fuel), it’s not at all clear that building all those plants that quickly would really reduce our collective carbon footprint much. More importantly, building a nuclear plant is incredibly expensive and time-consuming–a new 1,000 megawatt facility takes ten years and three billion dollars. And that’s after the plant’s owners have  found a location willing to host a political hot potato that could blow up. These things are not good investments. Nobody is going to build enough of them to replace fossil fuel any time soon.

Natural Gas

Natural gas, which is mostly methane, has been touted as a bridge fuel, a lower-carbon option that we can use until we can get off fossil fuel entirely. It is true that burning methane produces much less carbon dioxide than other fossil fuels do, but its carbon footprint is still pretty big–six times that of nuclear, for example. Methane is also itself a greenhouse gas, and as such is much more powerful than carbon dioxide. Exploiting natural gas inevitably results in some of the stuff leaking–in fact, about a tenth of the United States’ current methane emissions come from leaks at a single cluster of facilities. I don’t know whether anyone has figured the greenhouse effect of leaked methane into the carbon footprint of natural gas, but it’s a good bet this fuel is not the panacea it’s claimed to be. And then there is fracking, the dominant technique for acquiring natural gas, which carries its own high environmental cost.

To be clear, burning methane for energy is not always a bad thing. Once methane is at the surface and about to be released into the sky, burning it is the best thing to do, since that converts the methane to carbon dioxide, which is a weaker greenhouse gas. Electricity generated by burning landfill gas, which is what my husband and I buy, actually has a carbon footprint of less than zero as a result. Also, methane produced by decomposition recently–biogas or landfill gas, not natural gas–generally doesn’t change the planet’s carbon budget much because those carbon compounds were in circulation already (there are exceptions, of course). Methane has a place as a fuel in a post-petroleum world. It is only its fossil fuel form–natural gas–that doesn’t.

The big problem with natural gas is not even fracking or the details of its carbon content. The big problem is that the more natural gas we harvest, the cheaper it will get. Low costs drive more consumption. We could end up burning more fossil fuel than we otherwise would, offsetting the value of a switch from coal to natural gas. Investing in new natural gas infrastructure would also make it harder and more expensive to switch to renewable fuel later. As a bridge fuel, it’s a bridge to nowhere because using natural gas makes switching to renewables less likely.

Cold Fusion

Cold fusion is a form of nuclear power in which energy is harvested from the combination of small atomic nuclei, rather than the splitting of large ones, as in standard fission power plants. The trouble with it as a power source, is that fusion needs very high temperatures in order to get going–like the inside of a star or a hydrogen bomb. Cold fusion involves somehow persuading this reaction to occur at more reasonable temperatures (not necessarily cold by human standards) so we can put it inside a power plant. Science fiction writers have long assumed that someday this puzzle will be solved and we will then have cheap, abundant energy with no pollution or radioactive waste forever.

Whether the technology is anything more than a sci-fi trope hasn’t been clear. Every few years, a team announces it has a cold-fusion device, but none actually pan out.

All that could be changing. Cold fusion (sometimes referred to by other names) has received more attention from researchers in recent years, with some apparent success. So cheap, abundant energy with no pollution of any kind might really be a thing soon. That’s great, right?

Maybe not.

The problem is that at least part of the issue with fossil fuel is precisely that it is a cheap and abundant energy source, and altering the energy balance of a complex system (like the biosphere) always alters the way that system functions and not always in a good way. Most if not all of our current environmental problems are a direct result of our species having an energy budget out of proportion to our other resources, like arable land, potable water, and the various mineral ores. More energy means we can use resources faster, which in the short term provided the illusion of having more resources. Our population ballooned into the billions and the lucky among us became the wealthiest people the world has ever known. In the longer term, faster resource use has come with a huge cost in terms of habitat destruction, pollution, soil exhaustion, and everything else.

Here is an analogy.

Let’s say you have a large pasture with a stream running through it in which you want to keep horses. The number of horses you can keep is limited by the amount of grass your pasture can grow. Fine, but you want more horses, so you buy hay to supplement your grass. Now, your pasture can hold more horses and you like that, so you keep adding more hay. If you add an infinite amount of hay, can you have an infinite number of horses? No, because growing grass wasn’t the only thing your pasture was doing–it was also providing your animals with drinking water and room to move around, plus recycling their feces and urine into fertile soil. If you keep adding horses and more hay, at some point your pasture is going to get overwhelmed and stop providing its other services. Your animals won’t starve, but they’ll end up standing knee-deep in their own waste, with nothing but sewage to drink and hardly any room to move around.

Adding more energy to the human economy is like adding more hay to the horse pasture–by removing one limitation, we free ourselves to exceed the other limitations that are still there. Global warming is the most obvious sign that fossil fuel is destabilizing the planet, and it is possible to imagine alternate energy sources, like cold fusion, that don’t change the climate. But those alternatives will almost certainly destabilize the system in some other way, because that is what adding cheap, abundant energy does.

So, What Can We Do?

The thing is, we can imagine inventing social and economic structures that would allow us to use cold fusion safely. We can imagine nuclear fission plants designed so that they do not blow up and do not create nuclear waste. We can imagine natural gas installations that do not leak. All of the drawbacks for all of these energy sources could, in theory, have work-arounds such that they can live up to their promises, but those developments are in the future if they are anywhere at all.

There is only one solution that requires no additional technology and has been proven 100% effective already; use less energy.

Yes, we’ll need some infrastructure changes, and some new inventions would be useful for letting us keep at least some aspects of our comfortable lifestyles. But, basically, we could stop warping the sky tomorrow by just turning the machines off. Every day we put off that decision is a day we change the climate.

 

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