Category: Science

New discoveries, the scientific method, and all matters relating to the scientific study of the physical world

Quebec floods

This Montreal Gazette story opens with a line which I expect will become increasingly commonly heard as climate change impacts worsen: “Premier François Legault said Sunday it might be necessary to force people in flood zones to move away to avoid taxpayers having to constantly pay to repair their homes.”

That seems sure to be one of the big sources of disruption: people living in especially vulnerable places, getting hit over and over by extreme weather, and facing pressure to relocate, all while feeling put out and entitled to keep living as they did before.

People who currently profit from fossil fuels want compensation if they are forced to stop, and people suffering the consequences of fossil fuels want compensation for their losses. The anonomyzing gulf between emissions in one place and impacts in another threaten to leave everyone unsatisfied. Meanwhile, more and more places whose habitability we have taken for granted may become unlivable as storms worsen, sea levels rise, and water scarcity gets harsher.

Greta Thunberg to the British Parliament

I was fortunate to be born in a time and place where everyone told us to dream big; I could become whatever I wanted to. I could live wherever I wanted to. People like me had everything we needed and more. Things our grandparents could not even dream of. We had everything we could ever wish for and yet now we may have nothing.

Now we probably don’t even have a future any more.

Because that future was sold so that a small number of people could make unimaginable amounts of money. It was stolen from us every time you said that the sky was the limit, and that you only live once.

You lied to us. You gave us false hope. You told us that the future was something to look forward to. And the saddest thing is that most children are not even aware of the fate that awaits us. We will not understand it until it’s too late. And yet we are the lucky ones. Those who will be affected the hardest are already suffering the consequences. But their voices are not heard.

Is my microphone on? Can you hear me?

Around the year 2030, 10 years 252 days and 10 hours away from now, we will be in a position where we set off an irreversible chain reaction beyond human control, that will most likely lead to the end of our civilisation as we know it. That is unless in that time, permanent and unprecedented changes in all aspects of society have taken place, including a reduction of CO2 emissions by at least 50%.

And please note that these calculations are depending on inventions that have not yet been invented at scale, inventions that are supposed to clear the atmosphere of astronomical amounts of carbon dioxide.

Furthermore, these calculations do not include unforeseen tipping points and feedback loops like the extremely powerful methane gas escaping from rapidly thawing arctic permafrost.

Nor do these scientific calculations include already locked-in warming hidden by toxic air pollution. Nor the aspect of equity – or climate justice – clearly stated throughout the Paris agreement, which is absolutely necessary to make it work on a global scale.

We must also bear in mind that these are just calculations. Estimations. That means that these “points of no return” may occur a bit sooner or later than 2030. No one can know for sure. We can, however, be certain that they will occur approximately in these timeframes, because these calculations are not opinions or wild guesses.

These projections are backed up by scientific facts, concluded by all nations through the IPCC. Nearly every single major national scientific body around the world unreservedly supports the work and findings of the IPCC.

Did you hear what I just said? Is my English OK? Is the microphone on? Because I’m beginning to wonder.

She’s right. Even among advocates of climate action there has been a deep and long-running unwillingness to be honest about what controlling climate change requires and the suffering that will arise if it isn’t done.

I think all the political leaders from this time (the carbon tax advocates and the clueless climate deniers) will be remembered as failures who had all the necessary information and technology but who still plunged humanity into the abyss because they were too controlled by the status quo to do otherwise.

Whether that abyss will just be a great amplification of the climate change effects we have already seen or something that challenges or destroys human civilization will depend on how quickly we can disempower the leaders holding us back and listen to people like Greta.

twitter’s an addictive land of trolls

I have written before about the cognitive and emotional (and insomniac) downsides of checking the news too often. It seems worth re-emphasizing how twitter is a worst-case scenario in this regard, at least for people more interested in developments in matters of public interest than developments in the lives of friends and acquaintances, where facebook is untouchable.

With twitter it’s possible to use any internet-connected device to get an endless stream of updates and — crucially — little decisions for as long as you want at any time of day. It’s an exercise perfectly crafted to short-circuit longer term planning, even at the scale of turning off your phone to get a night’s rest before a busy day tomorrow. Every tweet presents the cognitive task of interpreting the content; determining whether it contains any factual, ethical, or political claims; and then evaluating that content in light of what the user believes and what, if anything, they are trying to accomplish through engagement online. Even for fairly passive users, every tweet involves the decision of whether to publicly ‘like’ or ‘retweet’ it, forcing your brain to engage decision-making circuitry more often and immediately than when reading a news article or book. Of course the real addictive prompts come from the social features: the notifications that someone has ‘liked’ or responded to your tweet. That engages all the emotional machinery which we use to socialize with others, maintain or alter our beliefs about the world, and protect out own self-esteem. It also embodies the slot machine logic of unpredictable and variable responses to the same action, ranging from someone amazing expressing agreement or saying something clever in response to your message to the depredations of the most hateful trolls.

Twitter often exposes me to content which I subsequently wish I could unsee, including particularly blockheaded claims and arguments which tend to re-emerge with a sense of frustration and anger in the shower the next day. The platform isn’t entirely without virtues — it can provide useful or at least engaging up-to-the-minute information and analysis on ongoing events, it allows users to engage directly with people who would otherwise be inaccessible, and perhaps it does sometimes direct people to good quality information they wouldn’t otherwise see. At the same time, it’s the venue for the least pleasant interactions in my life and it’s a repository of almost limitless idiocy and unkindness.

I have resolved for now to “cut off the time wasters quickly. They can’t be won over and whatever value there is in publicly refuting their arguments doesn’t justify the time and stress commitment”. There’s really no alternative strategy possible, since the platform is so full of people who (a) aren’t debating in good faith (b) can never be convinced or won over and (c) only get nastier with repeated interaction. They can take decades of meticulously collected, analyzed, and reviewed scientist and ‘refute‘ it with a silly accusation about the scientist or the person referencing them, a conspiracy theory, or an disreputable source which is nonetheless equally accessible online. Maybe very early on engaging with them helps draw some of the undecideds who are silently observing toward well-supported beliefs, but that almost certainly ceases to be true once your back and forth with that person has become one of your top ten present-moment sources of annoyance and irritability.

Hypocrisy back and forth

Blair King (whose blog bio says he has an “Interdisciplinary PhD in Chemistry and Environmental Studies”) is one of the people who had sent a tweet arguing that only people who use few or no fossil fuels can call for decarbonization and who I linked to this rebuttal post. He subsequently wrote his own response to me. I appreciate the substantive quality of what he wrote, but I still disagree with his conclusions.

To begin with, he says:

The reason the charge of hypocrisy is used so often in this debate is because it represents a valid concern. We live in a world full of hypocrites who will say one thing in public and do another in the privacy of their own lives. The problem is that until you have personally tried to go without fossil fuels you can’t really understand how hard it really will be. So a hypocrite is apt to make claims that are not founded on an understanding of the scope of the challenge, usually that doing so will be relatively easy

Fair comment, but I don’t think I understate the cost, difficulty, or challenge of rebuilding of the global energy system, nor automatically assume people in the future will use as much energy as we do today. Saving the biosphere justifies major lifestyle changes.

He goes on to say: “[t]o suggest that we can make massive global political changes without anyone making individual changes represents magical thinking”. That’s not what I have been saying at all. My point is that it’s wrongheaded to argue that only people who don’t use oil can call for decarbonization and further that efforts at addressing climate change through voluntary individual action are hopeless. People will definitely need to make changes, but they won’t for the most part be voluntary and individual. People don’t individually decide what sort of power plants get built, where our raw materials come from, or how any part of our integrated, technological global society functions. A lot of those systems have actually been set up by larger entities like corporations and governments making choices, but so far that decision making doesn’t reflect a determination to control how much fossil fuel gets burned and thus how much climate change gets imposed on the world. Decarbonization requires large scale political change and the relevant criterion for evaluating our individual behaviour is whether it is promoting or impeding that transition.

Dr. King then goes on to talk about sea level, challenging my prior claim that there are “centuries of experience that the sea level is always at more or less the same height”. Oddly, he then includes a chart that directly supports my point. It shows sea level going back to 1880, and shifting from about 125 mm below the zero axis to about 50 mm above. Compared to what is being induced by us melting the Greenland and West Antarctic ice sheets, the variation he shows is trivial. As described in the sea level rise portion of the U of T divestment brief: “A 2009 Science article examined the relationship between atmospheric CO2 concentrations and ice sheet stability. The paper identifies how the last time global CO2 concentrations were at current levels, global temperatures were between 3 ˚C and 6 ˚C hotter and sea levels were ’25 to 40 meters higher than at present’.” Expected sea level rise resulting from business-as-usual fossil fuel use is of the order of 1 m to much more: well outside the scope of what anatomically modern humans have experienced, and certainly way beyond what our present-day seafront infrastructure was built for.

Dr. King doesn’t provide much of a response to my using David MacKay’s book as evidence that there is enough renewable and fission energy available to more than replace our current fossil fuel use. In the same paragraph, he argues that somehow the creation of hydrogen-powered airliners is a critical missing part of decarbonization. First, I don’t assume that people will or should be able to fly anywhere near as much as they currently do. Second, I make clear in my post that decarbonization is a progressive process that needs to begin with the fossil fuel use that’s easiest to eliminate before moving to the harder stuff. If you want to keep using them, planes and rockets need energy dense fuel so they’re both part of the hardest to shift portion of our emissions. I would be happy to see air travel become much rarer and more expensive, and accept that such a shift is probably a necessary part of our overall decarbonization effort.

On raw materials, Dr. King says:

Petrochemicals represent a treasure trove of stored chemical energy that simply cannot be replaced given our current scientific knowledge and energy systems.

I wasn’t saying that replacing fossil fuels will be easy. I have been consistent in saying it’s one of the greatest challenges humanity has ever faced and it’s far from clear whether we will manage it. That said, there is no basis for saying that fossil fuels are an irreplaceable raw material. If their precursors could be made by plants out of air and sunlight we can do the same thing: quite possibly at a smaller scale than today’s petrochemical-fed industries and at a higher cost, but again I accept that many things in a low carbon future will be rarer and more costly than they are now.

It might affect Dr. King emotionally to know that I have actually done a lot personally to reduce my fossil fuel dependence and contribution to climate change. I have structured my life so that I can do everything essential on foot: easily able to walk to work and to complete necessary errands. At times, I go weeks at a time without even taking public transit. I have never had a driver’s license or owned a car. I last flew in 2007 and the last time I visited my family and hometown was in 2009/10 by Greyhound, which we calculated would be substantially less greenhouse-gas intensive than flying. I live in a single room on a floor shared by three people. I don’t bring this stuff up in response to hypocrisy allegations because I think the whole ‘only someone who doesn’t use fossil fuels can or should call for decarbonization’ is logically unsound. It’s perhaps worth mentioning here in response to Dr. King’s argument that only people who have chosen to greatly reduce their footprint can know what sort of future they are calling for. I think I have such an idea and, if the alternative is imposing the kind of massive threat that we currently are on people in the future and non-human nature, I think those sacrifices and more are not only acceptable but mandatory.

The emotional tone of Dr. Blair’s post is a bit exasperating in that he seems to think that his level of contempt toward the caricature he has developed of me is itself somehow an argument. He and his supporters have gotten into a big huff because I blocked him on twitter. This easily bleeds into the utterly indefensible argument that anyone who you care to talk to has the obligation to listen to you, and to do so on a platform of your choice (brilliantly lampooned by XKCD). As most people now seem to accept, twitter is a pretty awful place made marginally more tolerable by the ability to block people. I routinely encounter climate change deniers and twitter users who don’t even try to respond to substantive arguments but who simply hurl abuse. If I didn’t block them, they would dominate my timeline. Furthermore, I think I have every right to block people whose tweets I don’t want to see: a category that still includes Dr. King and the other twitter users who took a personally interest in the matter of this banning who followed on after him in arguing that blocking him was very, very wrong.

Another basic error in Dr. King’s post shows in the title: “When political scientists do environmental science the results are not always pretty”. The question of what we ought to do in response to climate change certainly requires science to answer. We need to know how much warming will result from how much coal, oil, and gas burning and what consequence a given level of warming will have for humanity and the rest of nature. Actually deciding what to do, however, goes well beyond environmental science to incorporate politics, economics, and most fundamentally ethics. Condemning people in the future for thousands of years to live in a world which we destabilized and degraded through our selfish use of fossil fuels is a profoundly immoral choice. If we’re not going to make it, we need to stop producing new fossil fuel production, transport, export, and use architecture in rich and highly polluting places like Canada and then play a determined and good faith role in spreading climate-safe energy technologies globally. That’s not the “Chinese Communist Party and Russia’s Vladimir Putin” view, as Dr. Blair rather childishly alleges. That’s survival politics in the 21st century. The alternative is not to keep the cozy fossil-dependent world we have now, but see how rich and prosperous we can remain as devastating global change is making large parts of the planet uninhabitable and huge numbers of people start fighting over what’s left.

Overcoming fossil dependence and building the world we want

Don’t you hate it when people who use fossil fuel based products for everything from travel to medicine to telecommunications criticize the fossil fuel industry or say that we shouldn’t build big new fossil fuel projects? We have a civilization that depends so much on fossil fuels, and yet these environmentalists want us to stop investing in them and to move to other forms of energy!

I have seen this general objection many times. Here’s a sample:

  • @rigger1977 — You start the march Milan. Throw away all products made from petroleum.
  • @trevormarr1 — Milan, @JustinTrudeau and @RachelNotley please list 10 things you use daily that exist strictly GREEN & will not require any oil/fossil fuel influence in their existence, we can wait! Try not to look like a hypocrite as you waste Canada’s opportunity! Let’s see how GREEN u live?
  • @glen_lees — If there are all these options one would expect that you use zero fossil fuels
  • @MHallFindlay — Personal insults don’t add to the debate. Just curious: When was the last time you flew somewhere or drove a car? Demand is a key component.
  • @CdnLadybug — And do you drive a car, use a cell phone or any products whereby oil products have been used to produce it? ALL forms of energy necessary.
  • @sinclair_pam — You yourself preaching from a fossil fuel device…how will you keep the hysteria alive without social media…brought to you by fossil fuels
  • @jglapski — You used fossil fuels tweeting this hypocrisy.
  • @aybren — So how will you stay warm this winter when you stop using all fossil fuel products?
  • @brucelabongbong — If you hate oil and it’s products……stop using them….simple…..
  • @lamphieryeg — Tell you what, Milan. When you give up fossil fuels, let us know. Till then, see ya.

Yes, environmentalists do want to end investment in fossil fuels and shift instead to other forms of energy. And your hypocrisy objection is a lot less substantial than it may seem.

There are three parts to the counterargument: climate change makes it necessary to move on from fossil fuels, we have alternatives to them as both sources of energy and feedstocks, and system change happens at the political level and not at the level of individual choice.

Let’s begin.

1. Climate change makes it necessary to replace fossil fuel energy

Whenever we burn coal, oil, or gas we add carbon dioxide (CO2) to the atmosphere. That greenhouse gas reduces the amount of infrared (longwave) radiation which the Earth emits to space. This is incontrovertibly well established. We can directly observe the reduced outgoing radiation as well as the resulting temperature increase, since energy that isn’t being lost to space inevitably warms the planet system.

Describing all the consequences of warming so far exceeds the sensible scope for any blog post. The authoritative source is the Intergovernmental Panel on Climate Change. Their fifth assessment report covers impacts from sea level rise to loss of glaciers and snowpack, worse extreme weather, more serious wildfires, the acidification of the oceans from CO2 in the atmosphere, adverse effects on agriculture, and adverse impacts on human health. A report I helped write for the University of Toronto goes through many different forms of harm and the evidence for each of them (p. 25–60). All these impacts worsen as the level of CO2 rises.

The consequences to date are bad, but it’s vital to understand that the harm arising from fossil fuel use is delayed. It takes decades for the greenhouse gasses (GHGs) added to the atmosphere to have their full effect. In this sense it’s a bit like the delayed effects of alcohol. If you drink two bottles of wine in 20 minutes you probably won’t feel too drunk at minute 21, but you have set yourself up to be excessively drunk once the wine has entered your blood and brain. However bad climate change’s effects are today, that’s just a taste of what is already coming, and far far worse will be coming if we don’t stop adding GHGs to the atmosphere.

How bad could it get? Since the United Nations Framework Convention on Climate Change (UNFCCC) was negotiated in 1992 a consensus has emerged among scientists and policy-makers that warming the planet by more than 2 ˚C above pre-industrial temperatures would be “dangerous”. Some communities face grave risks at much lower levels of warming as even small amounts of sea level rise and other disruption threaten them. Under a “business as usual” scenario, the IPCC expects global CO2 to rise from the present level of about 400 parts per million (ppm) to over 700 ppm by the end of the century, with a corresponding temperature rise of over 4 ˚C. That doesn’t sound like much in the context of the weather outside or where you set your thermostat, but that kind of climate change is massively beyond anything anatomically modern human beings have experienced in the 300,000 years or so that our species has existed in its current form.

All around the world, human systems have been built to function in the climate where they now exist, based on centuries of experience that the sea level is always at more or less the same height, rivers have a certain volume, certain areas are good for growing crops, etc. Causing warming of well over 2 ˚C would invalidate all those assumptions, producing enormous challenges for human beings everywhere, massive new flows of migration, and almost certainly military conflicts as desperate people from one area are forcibly blocked from moving somewhere else. That’s the kind of world we get for people who are young today if we keep using fossil fuels and, because CO2 remains in the atmosphere for long periods of time, that disruption would continue for thousands of years.

As James Gustave Speth explains:

How serious is the threat to the environment? Here is one measure of the problem: all we have to do to destroy the planet’s climate and biota and leave a ruined world for our children and grandchildren is to keep doing exactly what we are doing today, with no growth in the human population or the world economy.

Sticking with fossil fuels is an option, but it’s an option with almost unimaginably horrible consequences. If we care at all about the welfare of those who will live on the Earth after us, we need to do our utmost to stop choking the atmosphere with CO2.

2. We have alternatives for both energy and raw materials

There is actually far more renewable energy available than there is in fossil fuels. That can be worked out intuitively as follows. Even if we used 100% of global fossil fuel production to try to heat the oceans, if the sun stopped warming the Earth they would nonetheless cool and eventually freeze to the bottom. My MIT Physics of Energy reference card says that the solar power incident on Earth is 174 petawatts (million billion watts). A large nuclear reactor has about one gigawatt of output, so the sun constantly striking the planet has energy akin to about 200 million large nuclear reactors (whereas we have actually built about 400 of them). The same card shows that complete fission of 1 kg of uranium 235 would produce 77 terajoules of energy, whereas monthly US electricity consumption is about 1 million terajoules. We can’t actually capture and use all the energy in either of those cases, but those figures can give us some initial hope about energy options aside from fossil fuels.

Cambridge physicist David MacKay released a free book that goes through all of our energy generation options, including fossil fuels with carbon capture, and the end result is that it’s entirely possible to have a global civilization where everyone alive gets as much energy as the average European today without altering the climate. It requires a vast new global energy infrastructure based on some combination of climate-safe options, but we need to keep massively investing in energy regardless of what form we choose. Keeping the global fossil fuel industry going will cost tens of trillions of dollars per decade according to the International Energy Agency. Is it smarter to invest that money in fossil fuel energy which has volatile prices, is unevenly distributed, and which theatens to wreck the habitability of the planet or is it smarter to invest in a post-fossi-fuel decarbonized global economy which can support human prosperity indefinitely?

In addition to pointing out how 85% of global energy use comes from fossil fuels, people who advocate continued investment in the industry point to the importance of fossil fuels as a feedstock, often pointing out how electronics or medical equipment are made using fossil fuels. The main response to that is that we use fossil fuels as feedstocks because the technology to do so is broadly distributed, and fossil fuels are cheap because we ignore most of the costs their use imposes on others. Fossil fuels aren’t made of anything special chemically. We can get carbon and hydrogen from all sorts of carbon-neutral sources. It’s just a question of investing in the right capabilities and breaking our dependence on old feedstocks and processes. We need new ways to make agricultural fertilizer without natural gas, run farming equipment without diesel, manufacture steel without coke, and make low-carbon concrete or concrete substitutes. That doesn’t need to happen all at once, and some fossil fuel uses will be much harder to displace than others, but the sensible thing to do is to start with the cheapest and easiest substitutions and work from there toward the harder ones. That’s a big part of what carbon prices of various sorts are meant to achieve.

3. How change happens

If your town is dumping untreated sewage into a river which then flows past other towns where people use the water for drinking, you might rightly object to the choice your community is making. Is the solution to build a home sewage treatment plant so that your share of the problem goes away? Or is it perhaps to stop urinating and defecating altogether?

In this case, it’s obvious that the only way to meaningfully change the situation is to convince the general public and decision makers to change the system for everyone. Exactly the same dynamic applies to climate change. It may be laudable when individuals work to reduce their personal CO2 footprint, but we all live in a society where fossil fuels are dominant. A slight reduction in demand arising from the voluntary choices of a few concerned people won’t resolve that.

If we want to prevent a global catastrophe arising from fossil fuel use we need to go way beyond what voluntary consumer choice and the operation of markets will do alone. We need top level political change and the replacement of today’s leaders, parties, and policies with new ones that appreciate the seriousness of our problem and who share the determination to overcome it. That’s part of what tweets opposing new fossil fuel projects are meant to achieve, and that’s why it’s rather missing the point to call out the people making them for not having zero personal emissions.

There are huge opportunities to be captured in the transition to global decarbonization. To begin with, we can overcome all the problems caused by fossil fuels. That includes climate change, of course, but there is also the way fossil fuel profits fund unsavoury regimes (another favourite weak twitter argument is that opposing new fossil fuel infrastructure in Canada is akin to professing love for Russia and Saudi Arabia), the air and water pollution, the habitat destruction, and all the problems that arise from fossil fuel price volatility. We can also build a dramatically more equal global energy system, replacing the one where a privileged subset fly constantly and live in massive poorly insulated houses with one where everyone on Earth has what they need to live a safe, dignified, and prosperous life. Getting there might require deep changes in our political and economic systems, and it will likely put an end to activities that are only possible with wasteful and intense fossil fuel use, but moving to an equitable arrangement is surely better for most of those alive today as well as for most of those who will follow us in the future.

Beyond all that, we have a chance to move from the energy system that has been built in the 250 years since the industrial revolution — which relies on resources which are non-renewable and located primarily in a few parts of the world, and which is causing climate change that threatens a planetary catastrophe within our lifetime — to an energy system that relies on the energy constantly bombarding the Earth from the sun, the leftover heat deep inside the planet, and fissionable materials. That new energy system could power human civilization indefinitely, allowing for thousands more years of safe and enjoyable human lives; the continued development of art, culture, medicine, and scientific knowledge; and the preservation of the beauty and sheer existence of the countless species now being driven towards extinction by our fossil fuel use.

Resistance to World Health Organization Ebola efforts

Another case of conspiratorial thinking, selfish politicians, and conflict threatening to make a deadly serious threat into a dire global emergency:

Pockets of “reluctance, refusal and resistance” to accept Ebola vaccination were generating many of the new cases, Salama said.

“We also see a very concerning trend. That resistance, driven by quite natural fear of this terrifying disease, is starting to be exploited by local politicians, and we’re very concerned in the run up to elections, projected for December, that that exploitation… will gather momentum and make it very difficult to root out the last cases of Ebola.”

Some people were fleeing into the forest to escape Ebola follow-up treatment and checks, sometimes moving hundreds of kilometers, he said.

There was one such case to the south of Beni, and another to the north, close to the riverbanks of Lake Albert. Both were inaccessible for security reasons.

Neighboring Uganda was now facing an “imminent threat”, and social media posts were conflating Ebola with criticism of the DRC government and the United Nations and “a range of conspiracy theories”, which could put healthworkers at risk.

Ebola was a particular fear of mine in childhood, and it remains very worrisome and uncomfortable where we now live in a world where periodic outbreaks are now treated largely as business as usual.

Bright or invisible rocket exhaust

LOX and RP-1 never burn absolutely clean, and there is always a bit of free carbon in the exhaust, which produces a luminous flame. So when you’re looking at TV and see a liftoff from Cape Kennedy—or from Baikonur for that matter—and the exhaust flame is very bright, you can be sure the propellants are Lox and RP-1 or the equivalent. If the flame is nearly invisible, and you can see the shock diamonds in the exhaust, you’re probably watching a Titan II booster burning N2O4 and 50–50.

Clark, John D. Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press Classics, 2017. p. 96

One-way rocketry

Finally somebody in authority sat down and thought the problem through. The specifications of JP-4 [jet fuel] were as sloppy as they were to insure a large supply of the stuff under all circumstances. But Jupiter and Thor [ballistic missiles] were designed and intended to carry nuclear warheads, and it dawned upon the thinker that you don’t need a large and continuing supply of fuel for an arsenal of such missiles. Each missile is fired, if at all, just once, and after a few dozen of them have been lobbed by the contending parties, the problem of fuel for later salvoes becomes academic, because everybody interested is dead. So the only consideration is that the missile works right the first time—and you can make your fuel specifications just as tight as you like. Your first load of fuel is the only one you’ll ever need.

Clark, John D. Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press Classics, 2017. p. 95–6

Pre-computer rocket propellant chemistry calculations

[Calculating rocket fuel performance mathematically] gets worse exponentially as the number of different elements and the number of possible species [of reaction products] increases. With a system containing carbon, hydrogen, oxygen, and nitrogen, you may have to consider fifteen species or more. And if you toss in boron, say, or aluminum, and perhaps a little chlorine and fluorine—the mind boggles.

But you’re stuck with it (remember, I didn’t ask you to do this!) and proceed—or did in the unhappy days before computers. First, you make a guess at the chamber temperature. (Experience helps a lot here!) You then look up the relevant equilibrium constants for your chosen temperature. Devoted and masochistic savants have spent years in determining and compiling these. Your equations are now before you, waiting to be solved. It is rarely possible to do this directly. So you guess at the partial pressures of what you think will be the major constituents of the mixture (again, experience is a great help) and calculate the others from them. You add them all up, and see if they agree with your predetermined chamber pressure. They don’t, of course, so you go back and readjust your first guess, and try again. And again. And eventually all your species are in equilibrium and you have the right ratio of hydrogen to oxygen and so on, and they add up to the right chamber pressure.

Next, you calculate the amount of heat which would have been evolved in the formation of these species from your propellants, and compare that figure with the heat that would be needed to warm the combustion products up to your chosen chamber temperature. (The same devoted savants have included the necessary heats of formation and heat capacities in their compilations.) And, of course, the two figures disagree, so you’re back to square one to guess another chamber temperature. And so on.

Clark, John D. Ignition! An Informal History of Liquid Rocket Propellants. Rutgers University Press Classics, 2017. p. 84 (italics in original)