The Climate in Emergency

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


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What the Frack?

I heard a few days ago that Pennsylvania had recorded its first earthquakes caused by fracking. I’ve been hearing for a while that fracking causing earthquakes and all sorts of other mean, nasty stuff, but I didn’t know exactly how. I figured this was a good opportunity to read up on the matter and write a neat little science-explainer post.

Except it turns out fracking doesn’t cause most of the earthquakes we’ve been hearing about. Fracking is bad, don’t get me wrong, it’s just that the situation is more complex.

The story in Pennsylvania is that there were a series of very small earthquakes almost a year ago. They were too minor to even notice without the help of instruments and nobody would have cared except that they were centered right next to  fracking operation. So, the authorities investigated and decided that yes, the fracking probably caused the shaking.

No, it didn’t, said the Daily Caller, a website about which I knew nothing and was frankly suspicious. I poked around on the site, and offhand, it looks to be a legitimate newspaper with a conservative, anti-environmental bias, but so far I haven’t seen anything too far off that wasn’t on the opinion page. More to the point, they’re almost right about fracking.

Fracking can cause earthquakes, but they are typically too small to feel, just as the quakes in Pennsylvania, were. The Daily Caller’s contention that the story is some kind of liberal media conspiracy seems off-base at best. But they are correct in noting that the US Geological Survey (USGS) says that fracking does not cause strong earthquakes.

As the USGS explains, induced earthquakes are caused by the injection of fluid into rock near faults capable of producing earthquakes, but how much fluid and when it is injected both matter a lot.

Fracking (or hydraulic fracturing) means using water and chemicals (mostly acids, lubricants, and poisons–the poisons are used to kill microbes that might otherwise damage the equipment. And yes, you can look up these chemicals) to break up deep rock layers so that oil or natural gas can flow more easily into the well. Once the fracture occurs, it doesn’t have to be done again, not for that well. Extraction commences, and most of the fracking fluid comes back up, along with the oil or gas. Because the injection operation is brief, involves relatively little fluid, and normally occurs in rocks that have already had some of their oil extracted by conventional means (thus freeing up some space) the resulting earthquakes are small.

What causes the big earthquakes is wastewater injection.

When oil or gas are pumped out of the ground, water comes, too. It may be a little water or a lot of water–usually, the proportion of water increases as the well starts to empty out. Wells are often abandoned, not because there isn’t any more hydrocarbon down there, but because there is to much water and separating it out gets too expensive. The water can come from a number of sources. Some of it was pumped into the well as part of the drilling process (either for fracking or for other forms of drilling), and then withdrawn again along with the oil. The water picks up substances from the rock in the process an becomes salty and toxic. Water can also leak into a well when the bore hole passes through an aquifer–though drilling companies try to prevent those leaks because the water causes various expensive complications for them. Sometimes when oil or gas are pumped out of the rock, water from nearby flows in to take up the newly emptied space. But oil and gas pockets generally contain their own water as well, because the organic ooze that became the hydrocarbon and the sediment that surrounded it were wet. Some of that water is salty because it’s seawater. Sometimes it’s fresh. For some reason I find the idea of underground pockets of ancient seawater charming.

But no matter how the water gets in there, it’s not safe to drink when it comes back out. Water is very good at dissolving things, and while it’s underground, it usually picks up several different toxins or radioactive substances. There are various ways to dispose of this stuff (some places spray it on roadways to control ice and dust, a practice of questionable wisdom). Injecting it back underground is not a new idea, and has obvious advantages–if it’s injected into the space that used to contain oil, the water can prevent subsidence. But if the wastewater is injected into rock that hasn’t had anything removed, it can cause earthquakes. Serious ones.

Wastewater disposal involves a lot more fluid than fracking does, and it continues as long as the oil pumping. Its impact on the rock is therefore much greater. And yet, even then, most wastewater injection wells don’t cause earthquakes. For the rock to move, there must be a pre-existing fault capable of causing earthquakes either near the injection site or somewhere the water can flow to from the injection site–sometimes the earthquake is up to ten miles away. So, the take-home message is that injection can’t cause an earthquake in a place where no earthquake could happen otherwise, but it can make those earthquakes much more likely. Like, hundreds of times more likely, as is happening in Oklahoma, and will likely continue happening for years after the injection stops.

The other take-home message is if someone ten miles away agrees to put an injection well on their land, the earthquake might happen under your house.

But there is a connection between fracking and strong induced earthquakes.

Scientists have known for decades that wastewater injection can cause earthquakes under some circumstances. They’ve known that there are some places where these wells just shouldn’t go. But in recent years, the economics of exploiting certain very wet carbon deposits has simply gotten too good to pass up–and fracking and horizontal drilling together have made it so. The result is more injection wells where they’re not supposed to be. So far, Pennsylvania has not had many injection wells, which is part of why it hasn’t had many induced earthquakes, but that could change.

As long as large volumes of wet hydrocarbons are being exploited, there will be large volumes of wastewater to be disposed of, somehow. It may be difficult to restrict disposal wells to those places that are not going to cause earthquakes. And as bad as injection is, all the other forms of disposal seem to be worse.

So it comes down to a societal choice–how much are we willing to pay to have oil and gas? Ad are the people making the decisions really the same people who end up paying the cost?

 

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Dam Problems

So, California is at serious risk of flooding.

As readers may be aware, the Oroville Dam’s emergency spillway came very near to failing a few days ago, triggering massive evacuations for people who live downstream. The situation has been stabilized, and people may now return home, but more storms are due in tomorrow, and so everything is very precarious.

Before I get to my point (climate change), I offer a brief synopsis of the situation and of the dam.

The Dam Situation

The Oroville Dam* blocks the Feather River, a tributary of the Sacramento River, and thus creates Oroville Lake, near Oroville, California. The dam was first proposed in 1951 and was finally completed in 1968 (and dedicated by then-governor, Ronald Reagan).  It is the tallest dam in the United States. Its primary purpose purpose is flood control, though it also collects water for both municipal use and for irrigating the San Joaquin Valley, and generates hydroelectric power.

Under normal circumstances, water released by the dam flows out through pipes at its base, to rejoin the Feather River. During floods, a spillway off to the right of the dam (that is the dam’s right, river-right) can be opened. Since the spillway gate is high up, close to the level of the top of the dam, water must flow from the gate down a long, concrete-lined path, to get back to the Feather River. So far so good. But on February 7th, a week ago today, the rushing water eroded a hole in the floor of the spillway. The concern was that if the hole grew large enough, it could undermine the spillway gate and cause it to fail–so the gate was partially closed. And the water started to rise.

Fortunately, there was a plan B in place. The earthen embankment to the right of the spillway is topped by a secondary dam that is lower than the primary dam. If the spillway system fails, water will spill over this secondary dam–called the emergency spillway–instead of over-topping the main dam (and possibly damaging it). On February 11th, for the first time in the facility’s history, water did flow over the emergency spillway–and began eroding the embankment.

Had the erosion gone on long enough, it would have undercut the secondary dam, washing it away, and sending a giant wall of water down over the homes of almost 190,000 people. Hence the evacuations.

Officials were able to drop the lake level enough to stop the flow over the emergency spillway and to make emergency repairs, but California’s rainy season still has at least two more months to run. A catastrophic failure at Oroville is still not out of the question.

Dam Climate Change

The Oroville Dam, like much of the rest of California’s water infrastructure, suffers from several problems.

American infrastructure generally is in poor shape, largely because it is politically much easier to fund new construction than to fund repair (I wonder, too, whether changes in the tax structure have starved public works–much of our infrastructure dates back to a time when America was much more civics-minded than it is today). So many dams are past due for maintenance. Oroville specifically might have gotten a concrete lining for its emergency spillway–as was suggested and rejected in 2005–had more funding been available. In that case, erosion would not have been a threat.

But Oroville was also designed for much smaller flood volumes than are now considered likely. Part of that is simply that the modeling is more accurate now, but part of it is that floods are bigger. There is more impermeable surface, preventing water from seeping into the ground before it reaches a river, and there are more extreme weather events, thanks to climate change. Droughts, like the one California just came out of, are deeper and longer, while rainy periods are wetter than ever before, too. The state is currently having its wettest year on record–2017 has topped the region’s typical annual rainfall already. The system just wasn’t designed for this.

Scientific American (as seems to be its usual) cautions that it’s too soon to tell whether there’s any link between Oroville’s dam problem and climate change, but acknowledges that problems like this will occur more frequently because of climate change. However, a study published six years ago explains that storms associated with “atmospheric rivers” do hit California more intensely in certain climate change scenarios–specifically, while average atmospheric river (AR) activity stays the same, the extremes become more so, with more storms, more intense storms, and warmer storms in some years. The recent storms have been AR storms, and at least some have been notably warm. That seems like a pretty clear link to me.

Variation in precipitation is not the only factor, either.

Snowmelt in California’s mountains has been getting earlier and earlier since the 1940’s. Regional, and possibly natural patterns are involved, and back in 1994, when this paper was published, researchers weren’t sure anthropogenic climate change was a factor. But that was 23 years ago. I bet they’re sure, now, I just haven’t tracked down a more recent paper on the subject, yet. Earlier snowmelt and warmer winters (in which more moisture falls as rain rather than snow) together mean that more water runs off the land without having time to soak into the ground–or be used by agriculture. That means both more trouble with flooding and with California’s aging dams and more serious droughts, potentially in the same year.

In fact, parts of California (though not Oroville or, as far as I can tell, the watershed that feeds Oroville Lake) are still in a drought, according to the US Drought Monitor (unfortunately, you won’t be able to find this week’s report is you visit the monitor after it next updates).

What does all of this mean for Californians? It means they need us to stop causing climate change, obviously. But the state will also need to make decisions about its infrastructure, its water-use plans, and its development patterns that are more in keeping with the climate change we’ve already locked in–and those decisions depend on accurate and up-to-date data and analysis.

Next time anyone asks you if it’s really important for state and Federal governments to have access to accurate climate science, you can talk about the thousands of people who might drown this winter if the Oroville dam fails after all.

We already know that the evacuation clogged the highways. Had the spillway failed, some people could have been overtaken by water in their cars.

*Yes, I linked to Wikipedia, even though I generally consider it an unreliable source. In this case, the details of the Wikipedia article are consistent with, and largely seconded by, what I’ve read elsewhere, but I’d have to cite a half-dozen other articles at once if I wanted to avoid Wikipedia in this case.-C.


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Nuclear Opinions

I’ve been thinking.

I’ve just watched a documentary from last month in which Miles O’Brian explored nuclear power. It was an interesting show, full of detailed but easy-to-understand descriptions of various types of reactors. The basic thrust of the piece was that resistance to nuclear power is wrong-headed in light of the threat of climate change and the existence of new, much safer, reactor designs.

My immediate impulse is to be suspicious of such claims. Like many people, I have a very negative association with anything nuclear–which may be deserved, but is knee-jerk nonetheless. I am suspicious of the jerking of knees. You’re never too smart to be dumb, as Jimmy Buffet says, and I doubt my emotional impulses are any wiser and more reliable than anyone else’s.

What I have heard is that the potential harm of a nuclear accident is so great that even a small chance of that accident happening is too great. That even a properly functioning nuclear power plant produces large amounts of radioactive waste that nobody knows what to do with. That although a nuclear power plant is free of carbon emissions in the sense that it has no smoke stack, huge amounts of fossil fuels are used to build the plant, to mine and mill the fuel, to transport it, and to decommission the plant afterwards. So nuclear power is actually carbon-intensive.

But I have heard all these things from people who are already opposed to nuclear power.

I am not a nuclear physicist. Neither am I an engineer. I do not understand the operation of nuclear power plants unless someone explains it to me in very simple terms, and I am not equipped to differentiate the accurate descriptions from the inaccurate ones. I am reduced, therefor, to deciding whether to accept the message based on whether I trust the messenger. I have friends whom I trust who are anti-nuclear activists. They aren’t physicists, either, but they are highly educated in other fields and seem to know what they’re talking about. Therefore, I am anti-nuclear as well. When I hear Miles O’Brian on television implying that nuclear power might be a good idea, my impulse is to distrust him, to wonder if perhaps he is on the take somehow (despite the fact that I generally admire his work).

Pay attention to how this works:

  1. I do not understand a topic, but I feel the need to have an opinion.
  2. I therefore adopt the opinion held by people I like and trust, even though my trust in them has nothing whatever to do with their expertise in the relevant topic
  3. Because I am now emotionally invested in my adopted opinion, the mere fact that someone disagrees with me is enough to make me question their competence and their professional ethics.
  4. Miles O’Brian is not a physicist, but he is a professional science journalist who has obviously spent several years intensively researching the nuclear energy field, including talking to a lot of physicists–and yet my impulse is to assume he is deliberately lying because he contradicts people who, so far as I know, have no more real expertise in the matter than I do. Thus have I made myself impervious to learning on an important topic.

This is exactly the same psychological process that causes some people to doubt the reality of climate change.

Now, the fact that I’ve apparently taken leave of my senses is not proof, all by itself, that I’m wrong about nuclear power being bad news. As they say, just because you’re paranoid is no proof they’re not out to get ya. But the jerking of my knee is a good indication that I need to open my mind back up, even if I have to do it with a crow bar.

Offhand, the new reactor designs do sound promising. Whereas the water-cooled reactors build in the 1960’s and ’70’s more or less have failure as a default mode, other designs exist that simply turn themselves off if anything goes wrong. For example, some use liquid fuel that expands if it gets too hot. In an expanded state, the uranium atoms are too far apart to sustain nuclear fusion, and the reactor cools back down again. Sounds perfect.

Except I don’t know what happens to the spent fuel afterwards or what the environmental cost of uranium mining and processing is. So maybe not so perfect. But it’s worth noting that the environmental cost of fossil fuel mining and processing is truly awful, so it might come out even.

I should do some research on this, but have not yet done so. My point is not to argue in favor of nuclear in this post. I can imagine that I might do so in the future, depending on what else I learn–while I doubt nuclear power can ever be rendered truly safe, the small risk of local or regional disaster might be better than the absolute certainty of global disaster we face otherwise. But I’m writing this post today because I’ve had an even more unsettling thought.

I’ve long maintained that we don’t need nuclear power and its various risks and costs, nor do we need new technological advances in renewable energy and alternative fuels. All of those approaches make saving the planet conditional on our getting “enough” energy by other means, but we’re never going to get enough because the human capacity for consumption has no lid. Some of us use tens or hundreds of times the energy our fore-bearers did, and, given the opportunity, I’m sure we could find some use for tens or hundreds of times more than what we use now.

Rather than committing ourselves to filling our hunger for energy and then engaging our ingenuity to find ways to live sustainably anyway, we should commit to living sustainably and then engage our ingenuity to fin ways to keep our luxuries and gadgets anyway. We should just turn the polluting machines off. Today.

But of course, I know we’re not going to. Hell, the United States of America doesn’t seem capable at the moment of electing people who think climate change is real, let alone mounting a grass-roots movement to radically re-shape our way of life. Ideal solutions are important to hold on to for perspective and as a useful starting point for brain-storming, but I’m in no way suggesting that we reject partial and imperfect solutions when they come along. We must cope with political reality just as we must cope with physics.

And herein lies the disconcerting thought.

Are we in a position where nuclear power, whatever its costs and hang-ups and difficulties, may be the best we can get?