I promised the listeners some followup to this past Friday’s show and here it is. First, you should know that I’m an energy nerd. I have been for years. I pass a lot of my free time reading technology white papers. These are long, arcane papers that generally require that one has some sort of a background in engineering or at least cursory knowledge of physics. The energy industrial, in general, is very complex. One needs a deep knowledge base in order to make informed decisions…. or to at least avoid being duped by policymakers and industry stakeholders. That’s unrealistic for most of our listeners. That’s why I’m here. Let’s begin.
First, let’s address the question of how many people Earth can sustain for an extended period of time. This question has been addressed by many over the centuries. The first example that pops into mind is the British economist Thomas Malthus whose Essay on the Principle of Population
held that limits to agricultural productivity were the ultimate barrier to perpetual growth. Over 100 years later, The Club of Rome published a book entitled The Limits to Growth that had a similar premise but tried to account for agricultural productivity that was subsidized by ammonia produced by/from fossil fuels. There’s a great slideshow here that summarizes the later work: http://limits-to-growth.org/the-limits-to-growth/
I’m going to cut to the chase. If you read these works and their criticisms you’ll eventually run into one truly hard limit: Phosphorus.
Phosphorus is a key elemental building block for DNA and RNA. There are no substitutes. Without it, life as we know it doesn’t exist. There’s a fixed amount of Phosphorus on earth and that doesn’t really change which is a good thing. Instead, it simply moves from areas of high concentration, such as phosphate rock, to areas of diffusion, such as being randomly dispersed in the soil or ocean sentiments. Phosphorus can still be recovered from these diffuse sources but doing so is kind of like the difference between simply picking up a red marble off of a table and having to dig through a garbage can full of black marbles to find a red marble.
Phosphorus availability, then, is a question of energy. If you do some back of the envelope math, you can reasonably conclude that earth’s long-term carrying capacity limit is somewhere around 1.5billion people… which is 5.5billion people less than we currently have.
Population reduction isn’t a pleasant thing. The range of experiences depends on the time frame. For example, consider the fastest shrinking population on earth: Russia. A variety of factors, such as chronic wealth inequality, has drastically reduced Russia’s birth rate. This is a slow population reduction and I guess one could deem this to be depressing. Another instance of population reduction took place during the Black Death in the mid 1300s. The world’s population fell by, 100million, about 25%, in about two decades. One could deem this to be horrifying. Now consider moving from a world with a population of 7billion to a population of 1.5billion.
How is this to be done? If this is done quickly by pushing things to the limit and allowing resource wars to break out it’s going to be quite ugly indeed. During World War II, ~3.7% of the world’s population died between 1939 and 1944. That’s not even close to the 79% population reduction that we need. So, “quick” is bad. Very bad. Way worse than World War II bad.
Slow is preferable, and, if you followed my paragraph about phosphorus production, slow is going to require energy. So where do we get this energy from?
First, let’s cross some things off of our list.
Wind power won’t cut it. Its variable nature means that electrical grids don’t really benefit from production above 5-10% of total demand.
Ocean power just isn’t a great option. It’s an incredibly hostile environment and the available resource isn’t as great as you’d imagine.
Geothermal power is limited in its potential scope.
Coal and gas are finite by definition.
Conventional nuclear can’t really supply more than it currently does.
Photovoltaic solar works nicely in sunny areas but can only provide up to about 40% of power demand as storing huge amounts of electricity isn’t feasible at the moment.
Concentrated Solar Thermal is a comprehensive solution but only for the Southwestern U.S, Australia, South Africa, MENA, and part of Chile.
The one true silver bullet in our energy arsenal is nuclear. Now that’s probably going to freak a lot of people out. When I say nuclear almost everybody reading this is going to think FUKUSHIMA! SCARY! RUN! YOU’RE CRAZY!
What’s amazing to me is that people tend to forget that Fukushima was a tsunami first. Even the internet seems to think it was primarily a nuclear disaster. If you Google “fukushima deaths” the first link that comes up is a Wikipedia article entitled “Fukushima Daichii Nuclear Disaster”. The third link is entitled “Fukushima estimated deaths from radiation.” WHAT THE HELL INTERNET? The tsunami killed ~18,000 people. The reactor itself didn’t kill anyone immediately or thus far as far as I know/can find. The high end of estimates of long term premature deaths due to cancer is ~1300.
Fukushima along with Chernobyl are examples of the absolute worst practices in nuclear energy. Light-water reactors being built today are several orders of magnitude safer than Fukushima which, itself, was probably two orders of magnitude safer than Chernobyl. The LFTR, a prototype of which was built in the 1960s at Oak Ridge National Laboratory, is probably at least two orders of magnitude safer than the safest reactors built today.
What are these “orders of magnitude” you ask? Nuclear engineers perform Probabilistic Risk Assessments (PRA) on reactors. These vary in their criteria but a simplified way of looking at it is what is the probability of the core being breached? State of the art light water reactors have a PRA of one incident in every six million years.
Is that an acceptable risk? What happens if there is a core breach? Is it the end of the world? If an LWR has a core breach the incident range is basically anywhere between Three Mile Island and Chernobyl. People still work at the other reactors at TMI today and live close by. The original Chernobyl exclusion zone had a ~25 mile radius. Mother nature didn’t care, though, as wildlife is now abundant within said exclusion zone.
Let me ask another question: is it an acceptable risk to continue burning fossil fuels willy nilly? Climatology, like economics, is full of interdependent variables which makes accurate predictions hard to come by. However, if one were to look at future climate change through the lens of a statistical cost/benefit model (like an options trader or a poker player), our current course of action appears to be irresponsible at best. Even if there’s only a 1% chance of climatologists being right about global warming, is it worth the risk when we have other viable options? I’d say no.
So nuclear looks like a good idea. However, I have some bad news regarding the LFTR: it’s probably not going to happen in the U.S. due to regulatory red-tape. That’s ok though. GE has had a cousin of the LFTR under development for quite some time called PRISM and they’re quite serious about building at least one.
So what should our listeners do?
Stories are like computer programs for humans so make sure you tell the right story. If someone believes in the fossil-fuel burning perpetual-growth status quo tell them the story I’ve told you above or send them over to the Punkonomics page where I’d be glad to chat with them. Telling the right story makes a bigger difference than you think. It’s at least half the battle.