The Climate in Emergency

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


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Corals

Corals have been turning up in my social media lately. Not the actual corals, of course, but stories about them. A very large coral reef has just been discovered in the mouth of the Amazon and the Great Barrier Reef is evidently badly bleached at the moment thanks to abnormally high sea temperatures. I figure this is a good time to talk about some coral basics.

Corals are animals in the same phylum as jellyfish—it seems odd that corals are climate losers while jellyfish might well be winners until one remembers that a phylum is a very large group. Sharks, for example, belong to the same phylum we do. So they’re not closely related, they just have very broadly similar structures.  Corals are colonial, so what might look like a single coral is actually a whole colony. Individual coral animals, polyps, are rather like tiny upside-down jellyfish, each sitting in its own cup-like exoskeleton.

Many corals depend on symbiotic algae (zooxanthellae) for food, though they also grab and eat plankton. The color of corals depends on the algae in their bodies. Under stress, corals will expel their algae, turning white in the process. That’s coral bleaching. Bleached coral isn’t dead and can get new algae, but until they do they are extremely vulnerable (and, one imagines, hungry). Frequent or severe coral bleaching events can kill corals, as can any additional stresses that might occur while the animals are vulnerable.

Unusually hot water is one cause of bleaching. The warmer the water is, the faster the algae photosynthesize, meaning the more oxygen they release into the coral bodies. While corals do need oxygen to live, too much oxygen is a poison and the corals dump their algae to protect themselves. Corals vary in their heat tolerance, but they live at the upper edge of that tolerance, so even slight increases in temperature can hurt them. Bleaching on a large scale appears to be new–there’s no evidence for it before modern times.

Corals have very narrow habitat requirements, especially those that use zooxanthellae. Their water must usually be clear and sunlit, for photosynthesis, so they cannot grow anywhere more than a few hundred feet deep. The water can’t be too hot or too cold. In theory, a warmer world could support more coral, since a larger portion of the sea would be warm enough for them. In actual fact, though, climate change is moving too quickly—new reefs cannot establish quickly enough to balance out those lost to increasingly warm water in the tropics where they live. Rising carbon dioxide levels are also causing the oceans to become more acidic, and acid water eats away at the calcium-rich exoskeletons corals build. It’s not to the point where corals are shrinking, but they grow more slowly than they used to. Changing ocean currents and storm tracks also can stress corals and are also related to climate change.

This year is especially bad because it’s an El Nino year, which piles its own warmth on top of longer-term climate change.

Corals face risks from other directions, too, such as water pollution and physical damage from boats. So, as usual, the losses we’re seeing come from multiple sources. Between one thing and another, corals around the world are in trouble. Some areas have lost 80-90% of their corals already.

Obviously, corals are intrinsically important themselves, but coral reefs also provide a lot of habitat space for other animals. Some, like parrot fish, actually eat coral. Many others hide in nooks and crannies in the reef or take advantage of different microhabitats in different parts of the reef—a coral reef has a lot more surface area than a barren sea floor, so the reef essentially makes the part of the world it occupies a lot bigger. Something like a quarter of all marine species worldwide depend on corals.

Reefs are the oceanic equivalent of rainforests in terms of their biodiversity. If we lose the reefs, we lose the reef inhabitants–which is another example of how climate change can simplify and shrink the biosphere by taking out many species indirectly.

Lest this seem all like doom and gloom only, remember that we can still do something about climate change if we hurry. So don’t get so distracted by the presidential horse race that you forget to vote climate-sane people into Congress. Despite what you may be seeing on social media, voting matters.

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The Carbon Footprint of a Book

So, I’ve got a book coming out.

Technically, this is a second edition. Last summer, I published my first novel, To Give a Rose, but a few months later my publisher had to drop the project for reasons that had nothing to do with me. After much difficulty and confusion, I have finally found a way to get my book back into print; it’s due out next month.

Of course, this will make me responsible for a huge weight of paper product when (hopefully!) I sell lots of copies. Of course I’m concerned about the environmental impact of all of this, so I set out to do some research, beginning with the search term “carbon footprint of a book.” What I found was interesting and somewhat contradictory and uncertain.

How Carbon Footprinting Works

The problem is that carbon footprinting anything is complex and uncertain. In theory, to find the carbon footprint of an object, you look at how it’s made, how it’s transported, how it functions, and what happens to it when it’s disposed of, add up all the sources of greenhouse gasses in all these processes, and there you go. The figure is usually expressed as pounds (or kilograms, or tons, or tonnes) of carbon dioxide equivalent–different greenhouse gasses have different warming potentials, so for simplicity we use the warming potential of carbon dioxide as a kind of standard.

The problem is that in practice literally adding up all associated greenhouse gas emissions is usually impossible. Our economy is so complex, and manufacturing chains are so long, that a single product–in this case, a book–might involve resources sourced in dozens of countries and handled in multiple factories in a dozen different countries. That’s hundreds or even thousands of steps, each of which could have its own separate greenhouse gas emissions.Totally unworkable.

Carbon footprinting depends on imagining a simplified version of whatever manufacturing process you’re looking at, one that has a carbon footprint approximately the same size as the real one. But this simplification process is always a judgment call, and different analyses of the same product can yield very different results.

There are two other sources of complication.

One is that similar products might be products of very different manufacturing processes. A book printed in the United States using paper made from American trees might have a different footprint than one printed in the UK on paper made from European trees because of differences in the forestry practices and energy grids of each country.

The other complication is that it can be hard to determine what belongs in a given object’s footprint and what does not. For example, the footprint of a book should clearly include emissions associated with felling and milling the tree used to make the paper, but should it also include the lost carbon sequestration potential of that tree? What about the car the logger used to get to the job site to fell the tree? What about the Freon in the air conditioner of that car, if the logger used the air conditioner on the way to work? And so on. Clearly one has to draw a line somewhere, but where? A particularly vexing version of this problem comes up with recycled paper. Obviously, processing the same fibers twice uses more energy than processing them only once, so recycled paper ought to have a higher carbon footprint than non-recycled paper–unless you consider that the carbon footprint of the initial processing belongs to the first, “virgin” generation of paper only, in which case the recycled paper’s footprint might be much lower.

Again, judgment calls abound and can differ.

All things considered, carbon footprinting is only a rough tool useful for estimation. Its best application is probably for comparison of several alternatives all analyzed according to the same set of judgment calls–for example, a comparison among different protein sources or different types of energy generation. The technique does not yield definitive figures. An object cannot have a known carbon footprint the same way it can have a known weight or size or calorie count.

Carbon Footprints of Books

A Canadian paperback

I was able to find several different versions of carbon footprint assessments of books. The most extensive was probably one published in the Journal of Industrial Ecology, which presented the footprint of a paperback book printed in Canada on American paper. Unfortunately, that journal does not make itself available for free and I don’t have money. I was only able to read the Abstract (summary), which is available for free but does not have as much detail as I’d like.

The study came up with the figure of 2.71 kilograms CO equivalent (CO2-eq) per book, based on a production run of 400,000 books mostly distributed in North America. That figure applied only to the book through its production up to sale. The study also looked at three different end-of-life scenarios for these books (how long they last, how they are finally disposed of, etc.), but unfortunately the Abstract didn’t describe those scenarios or list their results.

One curious result of the study was that post-consumer recycled paper had a much higher footprint than virgin fiber. As noted earlier, that could be due, in part, to debatable judgment calls in the analysis method, which the Abstract did not fully describe. However, the non-recycled paper they analyzed came from a mill that used wood residue and other byproducts to generate power, thus substantially reducing reliance on fossil fuel and yielding paper with a lower footprint. Presumably, a recycled paper plant would not have access to such residue and is therefore much more likely to depend entirely on fossil fuel.

A Finnish hardback

This analysis comes from a brochure on the environmental impact of Finnish book production. The brochure describes its methods in detail and is both easy to read and thorough. To read it yourself, click here.

Among many other interesting facts, the brochure asserts that a single book has a carbon dioxide equivalent of 1.2 kilograms. Again, that leaves out the impact of the book’s disposal. Does a Finnish hardback really have less than half the carbon footprint of a Canadian paperback? We can’t really say, because the two studies are not directly comparable, but it is possible–especially if Finland has a less carbon-intensive power grid than Canada does.

The brochure further states that the vast majority of a printed book’s footprint is in the production of its paper and in the printing process–fiber supply and transportation contribute relatively little (at least in Finland).

An American book

I also found a reference to an analysis of the American printing industry that gave roughly 4 kg CO2-eq per book and listed the use of virgin paper as far and away the highest contribution to the footprint–in apparent direct contradiction to the other two analyses. Probably the discrepancy is again due, at least in part, to details of how the analyses were completed.

What About eBooks?

eReaders

What about books that don’t require paper? eReaders themselves have a carbon footprint associated with manufacture, transport, and disposal. These devices also have other environmental impacts associated with the production of metals, heavy metals, and plastics which are important but are outside the scope of the article. According to at least one study, the carbon footprint of the ereader alone is cancelled out after a few years because of all the paper books it replaces.

Curiously, the number of paper books replaced could be much higher than it might at first appear, since they don’t just replace the printed books that people read but also the printed books that people don’t read. Roughly a third of all the books that arrive at a book store are never sold. These go back to the publisher and are either pulped and recycled or added to the waste stream. Presumably, some percentage of books are actually thrown out soon after purchase as well. Incinerating or landfilling paper releases its carbon, meaning that the carbon footprint of a book in the trash is higher than that of a book in a library. If each printed book in a personal collection has a shadow-footprint of sibling-books that never made it, then switching to ebooks could carry substantial carbon savings.

That’s assuming that more ebooks actually mean fewer printed books and fewer printed books wasted, something that is not necessarily true.

Books online

But there is a book difference between a book on a machine and a book on a shelf–once a book is printed and shipped, it causes no further emissions until its eventual demise. If the book lasts as long as the tree would have, which is quite possible, its eventual yielding of its carbon could be no different than the eventual rotting of an old tree. In any case, the longer the book lasts and the more people read it, the lower the carbon footprint of reading it gets. With an ebook, reading it requires electricity every single time–and for books stored in the cloud, electricity must be constantly in use to keep those books available on servers. I am unclear whether that continued electricity usage has been included in the calculation of the footprint of ebooks.

The internet uses a fantastic amount of energy, though exactly how much seems debatable. That’s the bad news. The good news is that companies with a large online presence can use their economic muscle to build renewable energy capacity and some have done so. eBooks could therefore be a potential driver of conversion away from fossil fuel use, if the industry chooses to put its weight in that direction.

Bringing It All Together

If indeed most of a book’s footprint is due to paper manufacturing and printing, if that figure is not unique to Finland, that suggests that whether a book is printed on recycled paper is actually a lesser consideration. The real bang for the buck, as far as shrinking footprints are concerned, lies in making paper manufacturing and printing more efficient and less carbon-intensive.

In both cases, the mechanical efficiency of the plants themselves could probably be improved, but I really don’t know. The big deal is almost certainly the power grid; the carbon footprint of a book depends largely on the emissions of the power grid its production is plugged into. Since the power grid also determines much of the emissions related to ebooks, shrinking the carbon footprint of a book is really about transitioning the power grid off of fossil fuels–and paper mills, printing companies, and internet servers can all help drive the transition by demanding capacity that other users can then tap into.

So, What Does this Mean for Writers and Readers?

Arguably, the carbon footprint of a book belongs to its reader–personal carbon footprinting assumes personal responsibility for anything we buy. Since the same footprint can’t belong to two people, that would mean authors don’t bear the weight of the carbon emissions of their books–but that way lies paralysis. A reader seldom has an opportunity to choose low-carbon books over high-carbon copies, and in any case, reading materials are seldom a significant part of household footprints. Readers are unlikely to drive any sort of change, here. Writers have a little more power.

Writers can ask their publishers to take certain steps towards “greening” their processes. The publisher may or may not say yes–we live in an era when writers who are not J.K. Rowling or Stephen King have very little power–but we do have options and can explore them. I have already asked the printer I’m using now to use a paper with a higher post-consumer recycled content when possible and they said yes. This was before I found out that recycled paper might have a higher carbon footprint, but I’ll stick with it, since it sounds like virgin paper is only lighter on carbon because its production has access to alternative power generation. That implies that recycled paper could be just as climate-friendly if the mill that produces it buys renewable power. I therefore intend to ask whether we can get paper from a company that does so.

Climate-friendly paper might not be available, but it’s worth asking. If enough people ask, it might become available.

 


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Climate Change and Food: Red Meat

I have talked about climate and food before in terms of how climate change influences the food supply, but what about the other way around? How does our eating influence the climate? As many readers are probably aware, a significant amount of our collective carbon footprint (about one quarter) comes from our food system and meat-based foods have a larger footprint than plant-based foods. But how much difference between foods is there? What is the best way to cut carbon emissions out of one’s personal diet? Does it matter whether the meat is local or free-range?

I didn’t know either. So I’ve done some reading.

The numbers don’t look good for meat

The short answers are that the difference is huge, the best way to cut emissions is to eat less meat, and free-range and local do matter but, as far as the climate goes, not very much. There are some complications and nuances, of course.

I found an article that includes a graphic showing the carbon footprints of various food types (chicken, beef, eggs, lentils, etc.) expressed in kilograms of carbon dioxide equivalent (CO2e) per kilogram of food. “Carbon dioxide equivalent” means all greenhouse gasses taken together and expressed in terms of their impact on climate. So these figures include methane. Logically, the numbers would be exactly the same with any other measure of weight–the point is there is a ratio between amount of food and amount of emissions.

The simplest thing is to read the article, which you should do anyway because it’s fascinating. Here is the link. But I’ll summarize the most striking parts–for simplicity, I’ll give a single numbers for this; instead of writing “5kg of CO2e per kg of food,” I’ll just write “five.”

Lamb is the most carbon-intensive meat by far, at 39.2. Less than five of that is transportation and processing, which presumably means that if you raised your own lamb in your back yard, killed it yourself, and then had a carbon-neutral barbecue, it’s number would still be around 36. The next-closest competitor is beef, at 27, and then the other animal-based foods on the list cluster between 13.5 and 4.8. In contrast, the various plant-based foods on the list all cluster between just under three and just under one. The importance of transportation and processing varies, but only in potatoes is it the majority of the total figure.

I can think of several possible complications (besides grass-fed vs. grain-fed, which I’ll get to later).

  • What if the animal is a by-product of another industry? For example, if a flock of sheep are managed for milk and wool as well as meat, so that only excess ram lambs are slaughtered, then the carbon footprint of the flock is the same as it would be if those excess animals were not eaten (letting them live as pets would actually increase the carbon footprint of the operation, aside from the other ethical questions involved). In such a case, the same kilogram of CO2e has to share meat, milk, and fiber,and the whole operation is much more efficient than it might seem, right?
  • Do the figures for animals include emissions from transporting animal feed?
  • Why is the footprint of cheese six times that of yogurt given that most of them are processed milk?
  • The study focused on food in Britain; are these numbers different in other countries, such as the United States?
  • What is the footprint of highly processed foods, such as candy or fast food?
  • Since different kinds of food have different nutritional profiles, how would this comparison work if the unit of comparison were nutritional value, rather than weight? Nutrition is complex, so it might be impossible to do that kind of study, but the issue could still be important.

I do not have answers to those questions.

In any case, clearly generally similar diets, such as two different versions of mostly-plant-based omnivory, might have extremely different carbon footprints. The study that released these numbers found that while the difference between eating a lot of meat and eating a little is huge, the different between eating a little meat and none is small.

What is so bad about meat?

The clear take-home message here is that giving up beef and lamb (except possibly where these are byproducts of dairy production?), and cutting way back on other animal-based foods, is one of the most powerful steps a person can take to address climate change (aside from voting!). So, why are meats so bad for the environment? We have to be very clear, here; this is not about animal rights, which is an important but separate issue.

I have not seen this issue addressed directly, but the Second Law of Thermodynamics, not to mention public tastes in food, is almost certainly relevant.

The Second Law states, in essence, that every time energy moves or changes form, some of it is lost. This is why, for example, a ten pound house cat needs to eat more than ten pounds of meat in its life. This is also why ecosystems always have more plant-eaters than carnivores and more plants than plant-eaters. Most of what an animal eats does not become meat–what happens to it? Some of it becomes bone or other tissues we don’t want to eat. Some of it is never digested and simply passed as feces–which decomposes into carbon dioxide or methane–or as flatulence, which is also methane. But most of that missing food is exhaled as carbon dioxide.

One way to think about this is that all carbon that is taken up by plants is ultimately either interred in long-term storage as fossil fuels, or released again to the atmosphere when the plant rots or burns or is metabolized and exhaled. Eating food is the exact chemical equivalent of burning fuel. So, when a human eats a pound of plant matter, “burning” that “fuel” results in carbon emissions. But when we eat a pound of meat, that meat represents all the plants that animal ate to grow that meat–and all of that plant-fuel is “burned,” whether in the meat-animal’s body or in the human’s. More plant-fuel burned means more emissions released.

Cattle and sheep are both ruminants, meaning they don’t actually eat food directly. The food they swallow is eaten by bacteria in their guts, which in turn create food for the cattle. So you get another layer of energy transformation and thus another layer of energy dissipation–the bovine gets less energy out of the food and has to eat more, so more plants are “burned” as “fuel” for somebody. And the waste product of these bacteria is methane, which is a very powerful greenhouse gas.

So, meat has a larger carbon footprint than vegetables and ruminants (cattle and sheep) have a larger carbon footprint than other animals (pigs, chickens, turkeys, etc.).

Does grass-fed matter?

Most animals raised for the industrial food supply spend at least part of their lives–and sometimes all of them–in some version of a small cage being fed some kind of grain-based, heavily processed diet. There are all sorts of reasons why this is a terrible, horrible thing and why if you are going to eat meat, you should really choose only free-range animals (please note that “free-range” is a legally slippery term and that finding meat that lives up to the intent of the phrase takes some research). Is the climate another such reason?

The answer to that one depends who you ask.

An animal’s personal freedom has no particular bearing on carbon emissions. What makes the difference is whether it is grazing or browsing, as opposed to being fed corn (as would happen in a cage or cage-like feedlot). Logically, feed carries a larger carbon footprint because it must be transported and processed, whereas pasture is eaten where it grows. In fact, one of the best ways to keep open land from being converted into housing developments is to put cows on top of it. All of that argues for grass-fed meat having either a smaller carbon footprint, or possibly a slightly negative footprint, if pasture sequesters more carbon than cattle release.

On the other hand, cattle, at least, have to live longer to get to slaughter weight if they stay on pasture. More time living means more time farting, which could mean a larger carbon footprint. And while cattle are healthier eating grass, they get more energy from eating grain (which must be why they gain weight faster that way). So a day eating grass presumably means more farts than a day eating grain, too.

Which argument is actually true seems unclear at this time and might depend on the details of the cattle operation in question. And I have not found anything on how free-range living might influence the carbon footprint of other food animal species.

Wait–haven’t there always been cattle?

This question was posed by one of my Facebook friends and it’s a good question. How could cattle be a factor in increased climate change given that cattle themselves are hardly new?

This was my answer:

xkcd land mammals

From XKCD, https://xkcd.com/1338/, used in accordance with the cartoonist’s policy

 

This graphic shows that almost half of the land mammal compliment of the planet, by weight, is cattle. The vast majority is either humans or animals that humans eat. The reason it makes sense to do this comparison by weight rather than by head is that weight is a good proxy for how much animals eat and, thus, how much plant “fuel” they burn and how much CO2e is released. Consider that the energy in a pound of mouse meat is probably similar to the energy in a pound of hamburger–about the same number of calories. There are some potential complications here, but two thousand pounds of mice probably eat very roughly the same amount as two thousand pounds of cow. So, the fact that our planet has a huge number of tons of cattle right now means that a huge amount of plant-fuel is being “burned” by cattle these days.

Now, I am fairly confident that while there have been cattle for millennia, there have not been THIS MANY cattle until very recently.

I also suspect that this massive pile of mooing would not be possible without fossil fuel–and it certainly wouldn’t be economical. Feed could not be cheaply moved in to feed lots and beef (grass-fed or grain-finished) could not be distributed widely enough to meet enough consumers to justify the size of the herd. If this is the case, then excessive cattle farts are simply another symptom of fossil fuel use.

But, even if the huge herd of cattle is new, surely something else was eating all those plants before, and releasing a corresponding amount of waste and flatulence? Like, all the wild animals we’ve squeezed out of existence lately? Maybe and maybe not. Perhaps a lot of those plants used to just not get eaten and to enter into long-term storage on their way to becoming fossil fuel. Or maybe the wildlife released more carbon dioxide and less methane and so had a lower carbon footprint. There are possibilities. Or maybe the farts of cattle are actually irrelevant to climate change and the real carbon footprint of food is only the fossil fuel use and the ecological degradation associated with it?

That one I do not know.


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Gone with the….

Wind has been in the news lately.

Cyclone Winston  became a named storm on February 10th and then spent 12 days blowing around the South Pacific–literally, the storm track curved back on itself and made a big loop, something I personally hadn’t known was possible. It crossed over Fiji as a Category 5 storm, killed 21 people, and literally leveled whole communities–a kind of destruction more typical of powerful tornadoes. At one point, the storm packed sustained winds of at least 186 mph. That’s the most powerful storm ever measured in the southern hemisphere.

Then, on February 23rd and 24th, a swarm of tornadoes swept through the United States, killing at least three and injuring many more. The storms (though not the tornadoes) actually passed over my area, giving us high, gusting winds and thunder. In February.

Of course, some kind of extreme weather probably occurs somewhere on the planet every day. It’s a big planet, after all. But these are both extreme extremes–Cyclone Winston was one of the most powerful tropical cyclones ever measured. And the tornado outbreak was in February. And they both relate to climate change–although, so do all other weather events, extreme or otherwise, since the climate changes on the just and unjust alike. Still, it’s interesting to look at the actual connections.

First, Winston. As I’ve written before, tropical cyclones with sustained winds of 75 mph or more are called different things in different ocean basins and different basins also have different storm seasons, and different storm behavior. In the North Atlantic, these storms are called Hurricanes. Winston was called a cyclone because it existed in the South Pacific where it is now late summer. So if it seems like we’ve heard about the “world’s most powerful storm” rather often recently, that’s in part due to the fact that we’ve had multiple basins turning up extraordinary storms, not multiple records being set and broken in just a few months. Still, we do seem to be seeing a lot of big storms lately.

As I’ve written before also, it is hard to tell for sure if tropical cyclones have been getting worse because we only have a few decades of quality data–and the way meteorologists study these storms vary from one ocean basin to another, too, which means that much of the data we do have cannot be pooled. We know that climate change should be making tropical cyclones stronger, more frequent, or possibly both, because the new climate involves warmer water and more humid air, both of which are what makes tropical cyclones happen–we just can’t actually see the changes yet because of the data problem.

But Winston was actually the result of multiple atmospheric cycles working together. Tom Yulsman write a clear and interesting article explaining these cycles. You can find his article here. To summarize, both global warming and El Niño were involved in the unusually warm water that fed the storm while an even shorter cycle, the Madden-Julian Oscillation, that changes over just weeks, made the atmosphere more stormy at just the right time. Day-to-day weather changes then steered the storm through its bizarre circular track and right over Fiji.

So the simple answer is that yes, while we don’t have the data to confirm it, we can be pretty sure that these record-breaking storms have some degree of extra edge due to climate change–and at the same time, other patterns also influence the situation.

Meanwhile, Cyclone Winston exemplifies another pattern–no matter how strong or weak a storm is, it’s going to be worse for impoverished people. Wealthy people can afford to rebuild and wealthy countries can afford to provide extensive aid. Many of those in Fiji can access neither wealth nor extensive aid–they are literally asking for help from the world. And because Fiji is very small and very far away from many of my readers’ countries, it’s all too easy to forget about them.  Please help if you can and spread the word.

As to tornadoes, again we have a serious problem with a lack of quality data. It’s hard to tell whether there are more tornadoes than there used to be when until recently there was no way to tell a tornado had happened unless somebody was there to see it. But recently some researchers have teased out a changing pattern. Apparently, the number of days per year that have tornadoes on average are stead or dropping, but the number of tornadoes per outbreak is going up. That is in keeping with the warmer, more humid air, which should make storms more powerful, and a simultaneous decrease in wind shear, also a result of global warming, which makes tornadoes less likely. So, fewer days when tornadoes can form, but on those few days, the storms are worse.

But February?

Tornado swarms in February are rare but hardly unheard of. But what some writers are saying–that the atmosphere is behaving “as though it were May“–is very striking. It’s an acknowledgement that this past week’s storm is part of a pattern that we usually don’t see and it is directly related to warmth. Specifically, the Gulf of Mexico grew unusually warm and did indeed create a kind of weather more typical of a warmer month. Given that the world is warming, these storms are a bad sign of things to come.


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Thanksgiving

The following is a re-edited version of my Thanksgiving post from last year. It’s still timely.

“It’s that time of the year again,” warns a cynical-sounding blogger, “when warmists try to link Thanksgiving and climate change.”

Nice rhetorical trick, isn’t it? The thing is that of course anything in human life can be linked to climate change because everything we experience either depends on climate in some way or influences it. Most writers seem to cluster around one of two main narratives: Thanksgiving as an opportunity to talk about climate change and agriculture (as in turkeys could get more expensive as feed prices rise because of recurrent drought); and Thanksgiving as an opportunity to talk about communication (as in what you have to do with your climate-skeptic relatives). These are excellent points and I’m not going to try to make them all over again.

Instead, I want to talk about gratitude. I want to talk about abundance.

Have you ever thought it strange that we give thanks by eating a lot? If anything, American Thanksgiving sometimes seems more a celebration of greed and gluttony, with a perfunctory discussion of life’s blessings thrown in among the other topics at the dinner time. And yet, it is precisely abundance that serves to remind us of what we have to be grateful for. Thanksgiving provides the illusion of infinite, inexhaustible resources because there is more food on the table than the assembled eaters can consume. It is that illusion we use to evoke and celebrate our abundance.

And it it is an illusion. There is no such thing as an infinite resource; use enough of anything for long enough and eventually you will run out. Even “renewable” resources are only sustainable if you use them slowly enough that they can replenish themselves. We know from sad experience that it is indeed possible to run completely out of precious things that once seemed all but limitless. Passenger pigeons, for example. And in fact we are running out of pretty much everything we need for life and everything we need to give life beauty and meaning. Often, the depletion is hidden by ever more efficient usage that keeps yields high even as the resource itself runs out. We see this with fisheries, with soil health, with oil…. It’s not that we don’t have enough of what we need yet (hunger is usually a distribution  problem, not a supply problem; there are more overweight than underweight humans right now). The problem is that we are using so much that the world is warming under the pressure.

Want a visual? Check this out:

See how big we are, relative to the rest of the biosphere? Humans already use more than the entire ecological product of the entire planet. That is possible because we are, in effect, spending planetary capital, reducing Earth’s total richness a little more every year.

I’m not trying to be gloomy for the sake of gloominess, I’m talking about the physics of the environmental crisis, the details of how the planet works. I’ve gone into detail on this before, but the basic idea is that the planet has an energy budget and that when part of the planet (e.g., us) exceeds this budget, the planet as a whole destabilizes. The biosphere actually shrinks and loses energy and diversity. One way to describe global warming and all its awful permutations is as a complex system being pushed into an entropic state.

We got into this mess by treating the entire planet as the thing a Thanksgiving feast is meant to simulate; literally endless bounty. And because we did that, our descendants will have a smaller, leaner table to set than our ancestors did–and the more we use now, the leaner that future table will get.

Does that mean we shouldn’t celebrate Thanksgiving? Of course not.

Real, literal feasts are never actually about unlimited consumption. We know perfectly well that the Thanksgiving table may groan, but it’s not actually infinite. It just feels that way, and it is that feeling that is important. The illusion of physical abundance is a needed reminder of the truth of spiritual abundance–which is the actual point of the holiday, the thing we’re supposed to be celebrating on a certain Thursday in November.

The psychological power of the illusion of abundance does not depend on vast resources, something families of limited means understand well. By saving up and looking for deals and cooking skillfully, it is possible to produce a sumptuous feast that feels abundant and actually sticks within a fairly modest budget. The spiritual value is accomplished.

That’s what we have to do as a species. We have to find a way to live within our ecological means–the first step is to get off fossil fuel–and yet work with what we have so skillfully that what we have feels like more than enough. By staying within a budget we can stop worrying about running out, which is true, if paradoxical, abundance. Then the planet will have a chance to heal. The biosphere will grow again. And it is possible, just possible, that our descendants will live to see a more bountiful feast than we will.

And that will truly be something to be thankful for.


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If We Stopped Tomorrow

What would happen* if we stopped causing climate change tomorrow?

It’s a fantasy, obviously, though an appealing one. It’s also food for a lot of interesting thought. What would life be like? What kind of climate would we be left with? Would climate change stop right away, or would there be residual change? Here, I’m going to explore the climate part of the question; if humans stopped producing greenhouse gas emissions right now, how would the climate respond?

For simplicity, our scenario is that all humans everywhere simply vanish and that all our machinery shuts itself down safely at once–I’ll ignore complications caused by unattended machinery blowing itself up and so forth. I want to be clear that I do not actually think my whole species should go extinct, I just don’t want to get pulled off topic by an overly complex scenario.

When do greenhouse gas emissions stop?

Emissions of different greenhouse gases stop at different times in our scenario. These gases are carbon dioxide, methane, nitrous oxide, and two groups of related gases, the chlorofluorocarbons and the hydrofluorocarbons (CFCs/HCFs), plus water vapor. I’m going to ignore water vapor here because the primary way its atmospheric concentration varies is not from emissions but from changes in the hydrologic cycle.

So, in our scenario, fossil fuel use and its carbon dioxide emissions stop immediately–but that’s only 57% of total greenhouse gas emissions worldwide by weight. Another 20% of the total is carbon dioxide from other sources, such as forest fires or aerobic decomposition. 14% is methane, 8% is nitrous oxide, and 1% is CFCs/HCFs. These gases come from different processes and some of these processes would continue a while.

Nitrous oxide comes largely from the production and use of nitrogen fertilizer. Its emissions should therefore drop off pretty quickly in our scenario. CFC/HCFC comes from industry and refrigeration and would therefore drop off much more slowly as abandoned refrigeration units slowly broke down and leaked. But the real issue would be methane and non-fossil-fuel-related carbon dioxide.

If the world were simple, then after our piles of wood and paper and other biomas finished burning or rotting (that might take a few years), atmospheric carbon oxide levels should stabilize. The only remaining emissions would be from natural wildfire or decay and that carbon would be taken up again as other plants grew. But the world is not simple. One of the things climate change is doing is shifting some places from forest to savanna. It’s unclear how much of that shift has happened yet, but it’s quite possible that some of our forests are essentially dead trees walking, so to speak. They won’t get the rain they need to survive and when they die they will be replaced by grass, shrubs, and the occasional tree, not forest. In that case, their carbon won’t be recovered, driving the atmospheric concentration up. One of the nightmare scenarios we’re looking at is if climate change caused by forest dieback becomes enough to cause further dieback–a runaway positive feedback cycle in which the planet starts warming itself.

If that nightmare feedback loop has not started yet, I doubt it would under our scenario, given the substantial emission cuts from the end of fossil fuel use. But elevated CO2 emissions will persist at least as long as it takes those forests doomed by climate change to die and rot or burn.

Methane levels might actually not drop in our scenario. Methane occurs as a fossil fuel and is also produced by anaerobic decomposition at the surface. Agriculture is a major source, mostly from rice cultivation and animal husbandry, and these emissions would probably taper off pretty quickly. Our vast herds of cattle are not going to survive us for very long. But landfills and leaky fossil fuel facilities will keep producing methane for a long time–only we won’t be here to capture and burn off those emissions (burning converts methane to carbon dioxide, which is actually a good thing because methane is a much more powerful greenhouse gas). So those emissions could actually increase without us. I do not have enough information to calculate what the net result would be. And the nightmare scenario is that melting permafrost liberates enough methane to warm the planet enough to melt more permafrost and release more methane….

So, what we’re looking at is that if humans vanished and neither nightmare cycle has begun yet, total greenhouse gas emissions would drop immediately by somewhere around 60% and then probably decrease further over a period of years. When the system would reach equilibrium seems unclear. The relative contributions of each gas would change dramatically as well, with methane becoming co-dominant with CO2 by weight. Since methane is both more powerful and less persistent in the atmosphere, this shift would be very important to anyone running climate models of our scenario.

How long will the climate keep warming after emissions stop?

Even if the atmospheric concentrations of all the greenhouse gases stabilized today (which under our scenario they would not), the global climate would continue to warm for a period of years. This lag between cause and effect is actually a very familiar principle; if physics didn’t work this way, cooks would not have to use timers because food would become fully cooked the instant it went on the stove or into the oven. Earth’s climate has a longer lag than it might otherwise because we have oceans and water can swallow a huge amount of energy before changing temperature, but basically things just take a while to warm. The experts aren’t sure, but Earth’s lag is probably around 40 years–which means we are now experiencing the consequences of the greenhouse gas emissions of the 1970’s.

In our scenario, then, the loss of humans does not start to show on our climate for another couple of decades. Only then will the planet start responding to the dramatic decreases in emissions.

How long will sea level keep rising after the warming stops?

Here is another familiar principle: ice takes time to melt.Glacial dynamics are a bit more complicated, since they receive new snow as well as lose meltwater and they move, but when scientists say a certain amount of melting is “locked in,” that basically means that a certain amount of ice already has the conditions necessary to melt. It’s like an ice cube set out on the table at room temperature; that ice cube is going to melt away to nothing even if the air in the room does not get any warmer. Because glaciers are very big, some of the melting now locked in might take thousands of years–or it might go faster. Scientists aren’t sure, and of course the rate of melt is likely to increase because the temperature will keep rising (for at least 40 years!), but however long the process takes, the melting we have already triggered will cause at least three feet of sea level rise, probably more.

How long will greenhouse gas levels stay elevated?

Under our scenario, and assuming those cycles of viciousness aren’t in operation yet, greenhouse gas levels would level off as soon as emissions stopped and then eventually start falling. How long would it take for the atmosphere to return to something close to what it was before? The answer depends on which gas you’re looking at.

CFCs/HCFs and their kin vary a lot. Some can stay in the atmosphere for thousands of years, some for less than a year. I do not know how many of each kind we have up there and in what proportions, but we’re looking at a process that begins immediately and lasts for a very long time. Nitrous oxide breaks down in the stratosphere and takes just over a century to do it. Methane is quick, lasting only about 12 years (my source does not say what any of these chemicals becomes afterwards–I am suspicious that methane may become carbon dioxide, a complicating factor!).

Carbon dioxide is the tricky part, since it can leave the atmosphere by several different means. Much of it is absorbed into the ocean pretty quickly, where it no longer causes the greenhouse effect but instead causes ocean acidification. Also, this mechanism only works if there is more CO2 in the air than what the water near the surface can absorb. The upper layers of the sea are getting “full” now, meaning that not much more CO2 will go into the water until ocean mixing brings new water up to the surface. Chemical weathering of rocks also absorbs CO2, as does, of course, photosynthesis. And that last is the complicated one.

If the distribution of plants across the globe is roughly stable, then carbon sequestration by photosynthesis will be roughly matched by carbon emissions from fire and decay. But reforestation–and the re-establishment of wetlands–could become a powerful force for carbon sequestration with humans out of the way. Unless environmental damage has in some way precluded regrowth, which is possible, and unless the nightmare cycle has begun.

Without factoring in regrowth, somewhere above 65% of our carbon dioxide will be absorbed by the oceans in the next 20 to 200 years and the rest will drop very gradually, finally reaching equilibrium after a few thousand years. If plant regrowth proves significant, the process could go faster, maybe much faster–there is evidence that reforestation following the conquest of the Americas caused the Little Ice Age. In our scenario, it would be the entire world regrowing.

So what’s the scenario?

Bringing all of this information together, we can fill out the details of this scenario.

Humans either vanish or somehow become ecologically negligible in November of 2015. Right away, that very month, greenhouse gas emissions drop by about 60% and then continue dropping gradually over a period of years. Atmospheric concentrations of these gases also start to drop right away, though more gradually. Within a few years, meaningful reforestation begins in some areas, possibly balancing out climate-related deforestation elsewhere.

But the global average temperature keeps climbing–and it’s climbing faster than ever because the oceans have absorbed enough energy that now they’re warming rapidly, too. Extreme weather gets more so. If there are any humans left, they are having a very rough time of it. Somewhere around 2055, the climate begins to stabilize, although what it looks like by that point is anybody’s guess.

But by that point the atmospheric concentration of methane has fallen and leveled off at whatever its new normal is. Carbon dioxide levels are starting to fall meaningfully. I don’t know whether there is the same lag on cooling as there is on warming, but by sometime around the turn of the century I’m guessing the planet has started cooling again–and the cooling gradually accelerates over the following century as nitrous oxide starts to break down and as more and more carbon dioxide is absorbed by the oceans and by growing plants.

All this time, the sea level is rising. Water creeps gradually across the hurricane-ravaged ruins of many of the world’s major cities and upstream into previously fresh areas of the world’s rivers. Oysters grow on the streets of Manhattan.

I’m guessing that the cooling will take much longer than the warming, because greenhouse gas levels will stay somewhat elevated for thousands of years. The  planet would also see a lot of delayed effects of the warming–along the lines of changing plant growth patterns or changing ocean salinity triggering various feedback loops. I don’t know what those loops would be or when they might occur. At some point the pace of change would slow enough that the biosphere will start to recover–but recovery from a mass extinction takes about ten million years.

Feeling depressed?

I don’t mean this as an exercise in pessimism. I mean it as an illustration of what optimism looks like at this point, what we can look forward to in the best possible scenario we can anticipate. If being limited to this as optimism bothers you, consider how the next generation will feel if we do not get our butts in gear right now.

 

  • Note: After writing this, I’ve thought of a bunch more complications that might change the details of the picture I’ve given. I stand by my factual statements, but my suppositions might be muddy. Creating a detailed, accurate climate projection is not my intention, though–that requires a supercomputer I don’t have. The point is to draw attention to the questions, to the issues of lag and lingering emissions–to provide food for thought.


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Your Tuesday Update: Windy Fudge

NRP just ran a story on why Hurricane Patricia can’t be blamed on climate changebecause it is just one event and single events can’t be definitively pinned on a trend.

Yeah, yeah, yeah, we’ve heard that before. And it’s entirely correct. Yes, this record-breaking storm is clearly related to a powerful El Niño, and no, we don’t know what the relationship between El Niño and climate change is. I’ve addressed all of that before, and probably so has every other climate change writer on the planet.

But that isn’t what people mean when they ask if this is climate change.

They’re not asking for a lecture about the difference between climate and weather or the definition of “trend” or any of that, they’re asking is climate change real? and is this the sort of thing we can expect more of? And the answer to both of those questions is unequivocally YES.

No, we don’t know if there has been a statistically significant change in hurricane behavior yet because we have no good baseline data to compare against. So while we can say Patricia was startling, we can’t really get a handle on how unusual the storm was. It had the highest winds of any storm measured, but we haven’t been measuring storms very well for very long. Yes, El Niño is a complicating factor. It’s important for anyone interested in seriously discussing climate change to understand these details so that we won’t be caught hanging when some climate denier twists them up for use as semi-true window-dressing for propaganda.

But all of that is a footnote to the story. The story is that unusually warm water produces unusually powerful hurricanes. Global warming includes the waters of the globe. This is what climate change looks like, among other things–monster hurricanes.

No single events will ever be pinnable to any trend because trends are only visible in multiple events. That isn’t going to change. It isn’t news. So, to NPR and every other journalist working on the topic, please stop misframing public questions in a way that allows you to answer “no” when the true answer to the real question is “yes.”