The Climate in Emergency

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


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Looking at Wind Power

Wind power has been in the news in my area lately, with the pros and cons of specific projects being argued in the papers. As often happens, these stories have raised questions for me, and inspired me to do a deep dive into the subject. Here goes.

In the News….

Remember Martin O’Malley? He ran for the Democratic nomination for president last cycle. I suspect he will try again and could well be president someday. He is still very much a rising politician. In any case, he used to be the governor of Maryland, my state, and as such racked up a very impressive environmental record. He takes climate science very seriously. And one of the things he did was to champion the Maryland Offshore Wind Energy Act of 2013, which incentivizes wind power in various ways. Various renewable energy companies have been attempting to take advantage of the opportunity. This spring, two companies received regulatory approval to build wind farms near Ocean City. Combined, the project would be only the second US offshore wind farm, and by far the largest.

There are a lot of issues involved in this project. Besides the hoped-for emissions reductions, there is the political value of getting a major renewable power facility up and running, and the economic value of a big manufacturing project. The turbines themselves would be made here in Maryland.

But not all issues are positive. There is concern that wind turbines can disturb or kill wildlife, and there are worries that wind power might not be as “green” as it’s made out to be. Finally, there are aesthetic concerns. Though I, personally, find wind turbines kind of cool-looking, plenty of people don’t, and the project has been pushed farther and farther offshore in order to minimize its visibility from the beach–tourism being a major source of Ocean City’s revenue. I have seen a photograph doctored to represent how the current project will look from shore when completed (it’s included in one of the articles I’ve linked to), and honestly I’m not sure whether the specks visible on the horizon are wind turbines or dust on my screen. But yet some in Ocean City remain concerned.

In comes Dr. Andy Harris, Eastern Maryland’s delegate to the US House of Representatives (and yes, he’s a medical doctor, too).

Representative Harris has sponsored an amendment (an amendment to what, I’m not sure) that would block Federal funding for site assessments for wind turbines within 25 nautical miles of the coast. This move, if approved, would effectively block at least one, possibly both of the planned projects. Not only would moving the wind farms further out take time that neither company has budgeted for, but the farther offshore a wind farm is, the more expensive it becomes. At a certain point, a project simply stops making good business sense. Representative Harris says he supports the wind farm, but is simply concerned about the business interests of his Ocean City constituents–but it’s worth noting that his overall environmental record is terrible. In general, the wind farms have a lot of public support (though less in Ocean City).

Pros and Cons of Wind

Politics aside, how do wind farms actually stand up, environmentally? The environmental cost of a wind turbine is not zero, for although there are no carbon emissions during operation, the same cannot be said for manufacture,transportation to the site, routine maintenance, and so forth. So, what is that cost? The answer depends largely on which data you include in your analysis and how exactly you ask your questions–which is one reason why it’s possible to find wildly differing conclusions on the subject, all apparently “fact-based.” With that in mind, I focused as much as possible on more scholarly sources, people who did not seem to be arguing for a specific preferred option. But it is possible I missed something. As always, this post is meant as the beginning of your research on a subject, not the final word.

Wind at Home

Most of the figures I looked at related to the large turbines used for utilities-scale generation. After all, my hunt for information was started by a proposed wind farm. It’s worth noting, though, that there are other forms of wind generation. Some turbines are small, designed for home use. Some are even portable. I expected that small-scale turbines would have a better environmental profile than large ones, partly because they just appeal to my taste (I WANT them to be better!), and partly because the absolute environmental cost of a small unit is obviously so much smaller. But the important thing to consider is not the absolute cost but the cost-benefit ratio, and according to one study, home-based wind turbines don’t always have a good ratio.

The way cost-benefit ratios are expressed in this context is payback time–how long does it take for the carbon emissions saved by using a turbine to equal the amount of greenhouse gas emitted during construction, installation, maintenance, and decommissioning of that turbine? If the payback time is shorter than the working life of the turbine, its net impact is carbon-negative (that’s good). If it’s longer, that’s a carbon-positive impact, meaning a net increase of emissions (bad).

Three figures go into determining how long payback time is for a given system: the total environmental cost of the turbine; how much electricity the turbine generates; and the environmental cost of whatever form of electricity generation the turbine replaces. Payback times in general are expected to lengthen in the future as the electricity grid, as a whole, becomes less carbon-intensive.  For micro-wind, both carbon cost and electricity generation can vary widely.

The study I mentioned analyzed several different turbines at several different locations. The “greenest” turbines were responsible for less than 200kg (441 pounds)of carbon dioxide—not good, exactly, but many people emit as much every day simply by commuting to work in the morning. Others topped 1,500kg (3307 pounds).

Meanwhile micro-turbines sited in windy areas could generate a respectable 40% of a typical home’s energy use, but turbines in large cities, where buildings block or dissipate a lot of the wind through turbulence, only generated about 2%.

So, if you live in a windy area and your house is relatively isolated, you can achieve payback in a year or so, if you choose a micro-turbine model with a low carbon cost. But in other circumstances, payback might never happen. You’re better off buying your electricity from the grid.

Wind and Birds

One of the most concerning charges against wind power is that turbines kill birds and bats and otherwise harm wildlife. Of course, so does climate change harm wildlife. As much as I don’t want anything to harm animals, a fair judgment depends on a realistic comparison.  Large number of birds are at risk of extinction due to climate change, so if wind power can slow climate change, then the birds come out ahead, unless the death toll from turbines is truly horrific.

According to a document by the Union of Concerned Scientists, the death toll from turbines is not horrific—no bird or bat populations are at risk from turbines. The number of individuals killed can be dramatically reduced by careful siting and other steps, such as locking the turbine blades when the wind is low. Bats are more active in calmer air, when turbines don’t generate much electricity anyway. Offshore turbines can negatively affect marine life, but can also create artificial reefs that help marine life, so again, proper siting is critical.

Carbon Cost for Large-Scale Wind

For a detailed look at both the environmental and financial costs of wind, check here. The article also addressed several specific common criticisms in quick detail. At present, payback time for utility-scale installations is one to two years, unless sited somewhere, such as peatlands, where the disturbance of development itself has a high carbon cost. A graph comparing the per-kilowatt hour cost of various forms of energy makes it difficult to compare the different renewables–because all of them are so low as to be indistinguishable from zero next to fossil fuel generation. Not that their emissions are zero, but it’s like trying to create a graph comparing the body weights of three different kinds of songbird, a mouse, a sheep, and a cow.

Does wind reduce carbon emissions as compared to fossil fuel? You bet.

At least wind reduces carbon if it replaces other forms of energy generation instead of adding to them. While the article does address the issue of standby generation (some people have charged that because wind doesn’t always blow, wind power requires the use of other forms of generation. The article acknowledges the point, but says the carbon emissions still end up going down), it does not address the issue of overall demand caps.

Let’s say we us X amount of electricity generated by fossil fuel. So if we bring X amount of non-fossil fueled generation online, will that mean the end of fossil fueled electricity? Or will the public just decide to use twice as much electricity?

The answer to that puzzle lies somewhere in a complex tangle of economics and policy. I am not prepared to answer it, but it must be answered. My guess is that this is a problem the free market cannot solve by itself, even assisted by subsidies. We will eventually need a cap on either total electricity use or total fossil fuel use in order to get off fossil fuel.

And get off fossil fuel we must.


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The Story of Global Cooling

I’ve been hearing climate deniers talking about a global cooling scare in the nineteen seventies for a while now, and I finally got curious about where this narrative had come from–I didn’t think it had been made up whole cloth, but I hadn’t heard word one about it from any credible source, either. You’d think that if climate scientists had thought an ice age was imminent as recently as the seventies, at least some of the scientists I know would mention it occasionally?

So, I looked into it. And I found not one but two explanations.

In one story, Peter Gwynne, a science writer for Newsweek, wrote a short article on an idea some scientists were kicking around at the time–that a thirty-year cooling trend might continue and develop into a real ice age. The article was published on April 28, 1975, and attracted enough attention that other publications picked up the story with their own articles. Books and TV shows followed.

Scientific American, my source for this particular story, explains that the cooling trend is

now believed to be a consequence of soot and aerosols that offered a partial shield to the earth as well as the gradual retreat of an abnormally warm interlude.

And that

there also was a small but growing counter-theory that carbon dioxide and other pollutants accompanying the Industrial Age were creating a warming belt in the atmosphere, and by about 1980 it was clear that the earth’s average temperature was headed upward.

Scientific American acknowledges that the global cooling thing has no legitimate place in the climate discussion today, and reports that Mr. Gwynne himself is somewhat embarrassed by the anti-scientific uses to which his writing is being put. He does stand by what he wrote, given the limits of available knowledge at the time.

Ok, but there are a couple of problems with that story, starting with the fact that the greenhouse effect was not a “small but growing counter-theory” in the 1970’s–the effect of carbon dioxide on the climate has been known since 1859. The first calculations of the human role in climate change were made in 1896.

And it’s not like global warming was some far-out thing nobody was paying attention to back in the 1970’s, either. No less a person than the fiction writer, Ursula K. LeGuin had started making oblique references to climate change as early as 1969 (her novel, The Left Hand of Darkness, includes a flawless description of the natural greenhouse effect, as well as a reference to an alien planet that is hot because “an exploitive civilization wrecked its natural balances, burned up the forests for kindling, as it were.” Several of her later books also refer to the Earth itself getting warmer, too). Perhaps more starkly, the 1970’s were when Exxon was busy figuring out what it was going to do about global warming, of which its internal documents prove it was well aware.

Beyond all that, there wasn’t a 30-year cooling trend, except perhaps in a mathematical sense. According to the National Oceanic and Atmospheric Administration (NOAA), the period from the mid-1940’s to the mid-1970’s was cooler than previous years had been, but there was a lot of minor temperature fluctuation, not a consistent cooling. A cool period of relative stability is not the same thing as an oncoming ice age.

So, I did some more poking and found the second story.

Apparently, in the 1970’s, the greenhouse effect was well-known, but the cooling effect of sulfate emissions (“aerosols”) had just been discovered and it wasn’t clear yet which would prove dominant. A few climate scientists thought the aerosols might win out–between 1965 and 1979, 10% of the scientific papers on the subject predicted cooling, but 28% could make no prediction and 62% predicted warming. In other words, the coming ice age was a legitimate scientific idea for a while, but only a small minority of studies ever supported it.

I’m not actually sure, based on what I’ve read, whether anybody ever proved that sulfate emissions couldn’t have counteracted carbon emissions under some scenarios that were plausible back then. As history has actually played out, sulfate emissions have been dramatically reduced (they also cause acid rain), while carbon emissions have continued to climb. Aerosols still complicate climate predictions, but no one thinks they’re going to cause an ice age anymore.

There’s no cooling trend mentioned in there.

The way I see these two stories blending, I suspect that what really happened was that the end of the warming trend of the first third of the 20th century was taken (maybe correctly) as evidence of the cooling power of aerosols. Some climate scientists thought the aerosols could go on to trigger a cooling trend, but most did not. Peter Gwynne, being a writer who cared about science and about getting his writing published, chose to focus on the minority opinion, since that seemed more sensational at the time. He has admitted that the story “pushed the envelope a little bit,” in deference to Newsweek’s penchant for what Scientific American called an “over-ventilated style.”

The ventilation would have seemed harmless at the time, if the article was fundamentally accurate, as I’m willing to buy that it was. Nobody can represent the entire breadth of the scientific conversation on any one topic in just nine paragraphs. You have to choose which of all possible stories you’re going to tell, in order to tell any story at all.

That deniers have since pounced on his article for political and anti-scientific purposes is not Mr. Gwynne’s doing. Being co-opted is a risk all published writers run–it’s the Scylla to the charybdis of being utterly ignored.

Curiously, the one detail I thought would enter the discussion apparently didn’t, except as a note of context written long after the fact by one or another of my sources–astronomically speaking, we’re supposed to be in an ice age already.

The primary factor that dictated the glacial/interglacial cycle through recent geological history was the Milankovitch Cycle, an interaction between three separate variations in Earth’s orbit that together dramatically how much solar radiation we get at different times of the year. We’re at a point in the cycle where we should be heading into a new ice age, but aren’t because our carbon dioxide levels are too high.

The connection between that cycle and climate was confirmed in 1976, so it may be another thread of the “global cooling” story that none of my sources happened to tease out–but if not, there may have been good reason to ignore it.

The onset of ice ages is very slow. I have to cite one of my grad school classes here (Tom Wessels was the teacher–I’ve cited him as a source here before) as I haven’t been able to lay my hands on an appropriate link, but ice ages melt quickly (as in many hundreds of years) and grow slowly (as in many thousands of years). In fact, the warmest point of our current interglacial (before now, anyway) was thousands of years ago. No, the cooling was never enough to initiate continental glaciation on North America or Asia, but cooling was in progress.There is an excellent illustration of this cooling, and how long and consistent it was, here (yes, that is a web comic, but this one’s not a joke).

Sliding towards an ice age doesn’t look like anything special, it turns out. More or less, it looks like all of human history.

 


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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.