Putting the life back in science fiction

Next up, the ammonia economy?

This is another spun-off “strange attractor” from Antipope. It had nothing to do with the thread it was on, but the topic is interesting enough–if you’re into futuristic science fiction–that I wanted to summarize it here.

The basic idea is using ammonia as an alternate, carbon-free fuel. This isn’t as weird as it sounds, and there are a bunch of industrial efforts out there that might well project us into an ammonia age rather than a hydrogen one. Unfortunately, ammonia isn’t a panacea, so switching from fossil fuels to ammonia synthesized using solar or wind energy won’t be problem free. For those looking for dramatic conflict, ammonia has it.

Anyway, the fundamentals. Ammonia is NH3. If like me you’re lazy, you can go to Wikipedia’s article on energy densities, and find out that liquid ammonia has about 11.5 MJ/L of energy, slightly better than compressed natural gas (9 MJ/L) and liquid hydrogen (8.5 MJ/L), and less than propane (25.3 MJ/L) or gasoline (34.2 MJ/L), among many others.

As for making NH3, right now we make it in huge plants using the Haber-Bosch process, which makes ammonia using natural gas. Nitrogen is ubiquitous as N2 in the atmosphere, but N2 is a very stable molecule, and it takes a lot of energy to break it and turn it into NH3. Still, people are looking for better ways to do it. NH3 Canada is developing a miniature ammonia synthesizer that’s about four cubic meters in size and can produce 500 liters of ammonia per day, with each liter of ammonia taking 2 liters of water and 7.5 KWhrs of electricity to produce it. As a comparison, the average US home uses 909 kWhr per month or about 30 kWhr per day, which is about what it would take to make a gallon of ammonia using NH3 Canada’s technology. If it works.

To save you the math, that’s about 30% conversion efficiency, which isn’t bad. Ammonia synthesis could be used to store electricity from, say, wind turbines. The nice thing about NH3 Canada is that they want to use small units and stack them in banks, while the older technology uses huge furnaces to get efficiencies of scale.

What can you do with ammonia? You can actually mix it with gasoline and use it to run your car, if you get the mix right, and other researchers are working on creating engines that can run on pure ammonia. While there’s less energy in ammonia than there is in propane, it can be handled similarly. Pure (anhydrous) ammonia is fairly dangerous stuff, but then again, so is liquid hydrogen, and so are giant batteries if they’re fully charged. Energy density makes things dangerous.

Of course, ammonia has many other uses. We all know of it as a cleaner and fuel, and it used to be used in refrigerators before people switched to the much more efficient and dangerous CFCs [but see comments]. But it’s primary use is as a fertilizer and to make explosives, including gunpowder. Industrial nitrogen fixation underlies Big Ag all over the world, and it also underlies industrial warfare. Without huge amounts of gunpowder, things like machine guns don’t work, because there isn’t enough ammunition to make them fully functional killing machines.

Similarly, without huge amounts of nitrogen, the huge amounts of corn, wheat, and soy that are required to feed all seven billion of us wouldn’t exist. Some calculate that at least a third of us wouldn’t exist without fixed nitrogen in our food. The US has taken full advantage of this, and forcing huge supplies of cheap food on the world has been a major part of our foreign policy since the Eisenhower Administration. It was one way of beating communism, and protecting our high-yielding corn from things like being pirated by the Chinese is a matter of national security today.

I’m not a huge fan of Big Ag, even though I’d probably be dead without it. Still, if we want to switch from fossil fuels to renewables, adapting and expanding our existing fixed nitrogen infrastructure is a lot easier than trying to build the infrastructure needed to handle hydrogen.

That’s the good part. There are some downsides.

One is that when you burn ammonia in an engine, it produces NOx, which is a major source of air pollution. This can be fixed if there’s a catalytic converter on the exhaust pipe. I suppose, if you’re powering agricultural equipment, it might be possible to capture the NOx, convert it to nitrate or urea, and use it as fertilizer on the fields, thereby getting a second use from the fixed nitrogen.

One big problem with an ammonia economy is the same problem with renewables, which is that you’re capturing energy from the modern sun, and that’s all you get to play with. Fossil fuels use fossil sunlight from the last few hundred million years, and that’s a lot more energy. There’s no fossil ammonia, so we’d be stuck working in a lower energy environment. Currently, industrially fixed nitrogen takes about 1% of the global energy supply, but that’s a fixed 1%, and if it’s used for other purposes, people can starve. We’d have to ramp up NH3 production to store captured renewable energy, not depend on what’s already being made.

Still, I can envision a world where giant farms host an overstory of huge wind turbines, all hooked up to ammonia synthesizers. The farmer uses the ammonia to run his equipment, then uses nitrates captured from the exhaust to fertilize his fields. Aside from the scale and all the problems with nitrogen runoff and pollution, this isn’t a bad setup.

There are some interesting follow-ons.
–One is politics. If most of the world switches to synthesizing ammonia from sunlight or wind, the countries that depend on petroleum exports are out of luck. The only parts of the Middle East that would continue to matter to the US (and possibly China and Russia) are Egypt and Israel, due to the Suez Canal. This means that the burgeoning crises in the region would have to be dealt with semi-regionally, if at all. And that’s bad for all those refugees. Russia is likely to be a hold-out in switching off fossil fuels, since they get so much power from oil and natural gas, but switching to ammonia would change international politics as much as did the switch to using oil in the early 20th Century.
–A second issue is fertilizer. It is feasible to synthesize huge amounts of ammonia, but other elements are essential for plant growth, and the world is starting to run short of minable phosphorus. We may well have phosphorus wars in the future, but the simpler solution is to recycle sewage and manure onto fields. This has all sorts of public health and disease vector implications, but it will keep people from starving And there are menu implications–you want to eat raw salad from a field that receives sewage? It’s a common practice in the developing world.
–A third issue is air pollution. I can easily see people using ammonia to power things like home generators in areas where the power grid is failing, but if these machines don’t have decent filters on their exhaust, they will put out a lot of air pollution. The resulting smog will degrade the performance of any local solar panels, but it might be simpler than investing in huge batteries and a smart grid to provide power when the sun doesn’t shine.

And who will control the ammonia? A nitrogen-based economy has less energy than does the current oil-based economy. Energy becomes power when it is scarcer, even more than it is currently. Right now, we’re seeing how Big Oil distorts politics all over the world. Small ammonia generators, like the NH3 Canada machine, change the current game that is dominated by a few huge producers, because they mean that small-scale producers can make small amounts of fuel, at least in the short term. Probably this means that the advantage shifts from those who produce ammonia to those who build ammonia synthesizers and can best ship the ammonia from producers to consumers. Over time, I suspect that a few big ammonia producers will dominate the industry in any one area. They will be, quite literally, power brokers.

Still, switching to ammonia could slow down global warming, because the great advantage of NH3 is there’s no carbon emission from using it. It beats things like bio-diesel and biomass cold. Unfortunately, we’re seeing increasing methane emissions from the Arctic, so even if we get civilization’s carbon emissions under control, we may be passing the tipping point as you read this. We’ll see.

If you want to write a SF-thriller set in the next few decades, you could do worse than to power the world with ammonia, and make the Politics of N a centerpiece of the story. After all ammonia isn’t just a fuel, it’s a cleaner, fertilizer, and a refrigerant. Who wouldn’t want to get rich off it? Something to think about.


That brief window
July 29, 2015, 9:35 pm
Filed under: deep time, futurism, Worldbuilding | Tags: , ,

Well, the book manuscript is done, and I’ve got some beta readers going over it while I figure out the strange world of non-fiction publishing. As I understand it, one not supposed to write a non-fiction book on spec, but rather to have a contract to write the book based on how well you can convince the publisher it will sell, based on your audience. And simultaneous self-publishing is a thing too, apparently. Interesting business, especially when I write a book of 100% speculation about a climate-changed Earth, and it’s called non-fiction.

So I have time to blog more regularly.

One of the things I’ve increasingly noticed is how bad we are with big numbers, and dealing with big numbers turned out to be a central feature of the book. In general, when we look at phrases like a few years, or a few decades, or a few centuries, or a few millennia, or a few thousand years, or a few million years, we fixate on the “few” and ignore whatever comes after that. As a result, we get weird phrases like the Great Oxygenation Event, which took a few billion years back when the Earth switched from an anaerobic atmosphere to aerobic one. It doesn’t sound like much, until you realize that animals have been on land less than 500,000,000 years, or less than a quarter of a billion years. The Primitive Animals Invade the Land Event will end with the expanding sun making such life impossible on Earth long before our little event matches the length of the Great Oxygenation Event, yet people some people still think that the Earth was oxygenated very suddenly, rather than incredibly gradually. All that happened was that people ignored all the zeroes, called a process an event, and confused themselves and their audience.

This applies to human history as well. If we take the Omo 1 skull as the oldest modern human, we’ve got at least 195,000 years of history to our species already.

We’re young compared to most species, but we’ve still got a lot of history, and most of it is lost. Our documented history is about the last 5,000 years, and the archaeological becomes fragmentary shortly thereafter. In other words, thanks to writing, we’ve got partial access to about 1% of our apparent history as a species. The conventional interpretation of this is that humans were basically boring for the first 99% of our history, then something changed, and we took off like gypsy moths, expanding into this outbreak of humanity we call civilization. Prior to that, we were peaceable-ish hunter gatherers living in harmony with nature.

What changed? The more I read, the more I tend to agree with the archaeologist Brian Fagan. In The Long Summer, he postulated that civilization arose after the last ice age because the climate stabilized after the ice age, not because humans changed in any real way. There’s some evidence to back him up. Alvin Alley, in the Two Mile Time Machine, talks about Dansgaard-Oeschger (D-O) events in the glacial record. These are times when the global temperature bounces back and forth many degrees, and they are thought to be due to ice from Hudson’s Bay glaciers messing up global thermohaline circulation in a semi-periodic way. Basically, the climate at Glacial Maximum is stably cold, the climate in the interglacial is stably warm, and the times between those periods have the climate oscillating between cold, colder, and coldest in something like a 1,500 year pattern with lots of noise. In such a continually changing global environment, things like agriculture would be difficult to impossible, so it’s no surprise that humans would be nomadic hunter-gatherers. If there were something before the D-O events, the evidence would be lost, and the absence of evidence would make us think that, until 5,000 years ago, we were primitive savages.

If you’ve been following the news, you know that evidence for agriculture 23,000 years ago turned up in Israel (link to article). The last glacial maximum happened from 26,000-19,000 years ago. If one believes that stable climates make things like agriculture possible, then it’s easy to believe that someone invented farming during the last glacial maximum, and that it was lost when the D-O events started up and their culture shattered.

So how often did humans go through this, discover and lose agriculture? We have no clue. Except for that fortuitous find in the Sea of Galilee, when a long drought temporarily revealed an archaeological site that is currently underwater again, there’s no other evidence for truly ancient agriculture.

The last interglacial was the Eemian, 130,000-115,000 years ago. Did the Neanderthals invent agriculture back then? There’s little undisputed fossil or archaeological evidence from that time, and who knows if any evidence still exists. What we do know is that the Eemian people did not smelt a lot of metal, for there were ample ore deposits waiting for us to find them on the surface. We know they didn’t use petroleum or coal for the same reason, and there’s no evidence that they moved massive amounts of Earth or built great pyramids, as we’ve done. Those kinds of evidence seem to last. But if they had small neolithic farming towns, especially in northern Europe, the evidence would have disappeared in the subsequent glaciation.

This pattern applies to our future too, especially if climate change collapses our civilization and forces the few survivors to be hunters and gatherers. Our civilization would lose continuity, our history would vanish, our flimsy concrete buildings would collapse into rubble, and coastal ruins would disappear under the rising sea. What would remain of us, except our earthworks and our descendants? My rough guess is that such an age of barbarism would last between 200 and 2,000 years before the climate stabilized and civilization became possible again. Would the people building their civilization on the other side think they were the first civilized people, too, that their history began when they were created a few thousand years prior, as we used to think?

That may be the fate of future humanity on Earth, even if our species lasts a billion years. When the climate is stable for thousands of years, there will be outbreaks of humanity–what we call civilization, when we temporarily escape nature’s constraints, grow fruitful, and multiply to fill the place. In between these outbreaks there will be far fewer of us, and we’ll live in smaller, simpler societies. What we will know will be a balance between what we’ve retained and (re)discovered, and what crisis, collapse, and continual change has caused us to lose. Our history, at any one time, will be that brief window of a few thousand years between discovery and loss, with only enigmatic artifacts, like those 23,000 year-old seeds, to tell us that we weren’t the first ones to discover something. They’ll be enough to hint at how much history we’ve lost, but not enough to let us recover it.

Hobbits of the ATM?

No, I haven’t seen the latest offering Peter Jackson yet, but I will soon. Still, in honor of the latest, erm, extension of The Hobbit onto the big screen, I thought I’d pitch out an interesting possibility for the future of at least some of our descendents.

First, a definition: ATM isn’t the money machine. Rather, it’s an acronym for Anthropocene Thermal Maximum, which we’ll hit sometime after we’ve exhausted all the fossil fuels we’re willing to dig up into the atmosphere. If we blow off over something like 2500 gigatonnes of carbon, we’re going to be in the range of the PETM, the Paleocene-Eocene Thermal Maximum (Wikipedia link) about 55.8 million years ago, when global temperatures got as hot as they have been in the last 60 million years. Our descendents’ future will be similar, if we can’t get that whole carbon-neutral energy economy working.

One of the interesting recent findings is that mammals shrank up to 30 percent during the PETM (link to press release). The reason given by the researchers is that increased CO2 causes plants to grow more foliage and fewer fruits (in the botanical sense, so we’re talking fruits, nuts, grains, and all the other things we like to eat). This poorer nutrition led to smaller animals. I think there’s another possible explanation for the decrease in animal size.

My thought was that, if civilization crashes due to radical climate change into a PETM-type world, humans will be at the mercy of the elements, so it’s quite likely that future people will be smaller in size. Perhaps 30 percent smaller? Sitting down with the BMI graph and making a few assumptions, I found that the 30% smaller equivalent of a 71 inch tall male weighing 160 lbs is approximately 60 inches tall. Now, this is an interesting height, because it is the upper limit of pigmy heights in an interesting 2007 study by Migliano et al. in PNAS (link to article). Their hypothesis was that the evolution of pigmies around the world is best explained by significant adult mortality, which they adapted to by shifting from growth to reproduction earlier in their lives. The researchers found that the average age at mortality in pigmies is 16-24, and few live into their 40s. The major cause of death is disease, rather than starvation or accidents.

While I don’t know of any evidence of increased animal disease during the PETM, there is good evidence for increased plant disease and predation by insects (link), so it’s not much of a stretch to hypothesize that the animal dwarfing could have been caused by increased disease, decreased lifespans, and a resulting shift towards smaller body size and early reproduction.

So, here’s the idea: if we blow too much carbon into the air, and our ATM rivals or exceeds the PETM, at least some of our descendents will be the size of pigmies, due to the harsher environment (more disease, less medical care) favoring people who mature earlier and have kids as teenagers. They probably won’t be hobbits unless a hairy-footed morph takes off somewhere (perhaps in the jungles of Northern California?), but they will be technically pigmies.

It’s not the most pleasant thought, but if short lives and statures is troubling, the good news is that post-PETM fossils show that animal species regained their former size once the carbon was out of the air. And, according to Colin Turnbull’s The Forest People, life as a pigmy isn’t necessarily nasty or brutish, even if it’s short.