This is my first post… I guess started because of a comment on the previous post by Jon. I was in the middle of writing a long comment, then decided to flesh it out and add some references.
I used to almost buy into the Peak Oil idea, the idea that we’ll run out of oil someday and face an energy-starved Apocalypse. I never believed that last part because I’ve always been a big believer in nuclear power and realized America had vast amounts of coal (which can be converted into oil products via the Fischer-Tropsch process which was used extensively by Nazi Germany and then later by apartheid South Africa). But I figured that it would at least mean we’d eventually be forced to use renewable energy and nuclear power at some point.
But then I learned about Oil Shale (not to be confused with fracking) or kerogen shale, basically rock that has semi-solid organics inside that can be extracted into oil. https://en.wikipedia.org/wiki/Oil_shale
Turns out the US has the biggest such deposits in the world. Much more such oil than Saudi Arabia has traditional oil. Like 4 trillion barrels of oil shale (in place). More than ten times the size of the in-place reserves of the Bakken formation (shale oil… tight oil… basically, oil that is extracted by fracking). Of course, this is expensive to extract. But as technology improves, and the price of oil is high enough ($50? $100? $200/barrel?), it can be extracted, just like the tar sands of Canada.
I’m a techno-optimist. I think technology will allow us to continue getting better and better at extracting carbon from the ground. We have hundreds of years of coal (at least in the US) using current reserves and methods. Total estimates of the amount of proven reserves of coal are just under 1 trillion tons, of which the US has over a quarter. To put that in perspective, the atmosphere contains about 3 trillion tons of CO2. But remember that burning carbon combines it with 2 atoms of oxygen, meaning that if you burned all the world’s proven coal reserves right now, you’d literally double the atmospheric concentration of CO2. (Note: if you burn it slowly over decades, about half is absorbed, i.e. by the ocean in the form of carbonic acid…)
Using more advanced tools, we have tens of thousands of years. Basically all of northern Alaska has coal underneath it (thin layers, but still): http://groundtruthtrekking.org/Issues/AlaskaCoal/HowMuchCoal.html
The total amount of in-place coal in Alaska is something like 5 trillion tons. This is a much larger estimate than decades past. Yup, about 5 times the proven reserves of the entire world! Burn that immediately, and we’d multiply the atmospheric concentration by roughly 6x. Who knows how much is underneath northern Canada or Greenland or Russia… Or countless other places in the world.
We keep finding more carbon underground. The Shale Revolution is proof of this. Tar sands in Canada is proof of this. Oil Shale is proof of this. We. Won’t. Run. Out.
But the problem is that, given current climate models (which no doubt most of you have problems with) we can’t even afford to burn all of the currently proven reserves of coal, let alone ten or a hundred times that much as technology improves. That would put as much CO2 in the air as there was when the Sun was significantly less bright (young stars like the Sun are a little dimmer than stars the Sun’s age), meaning the climate would be FAR warmer than it was last time the atmosphere had that much CO2.
We’re not talking about 4 degrees F difference, we’re talking 20 degrees F. Probably much more (depending on how good we get at removing coal from the ground …and depending on poorly-understood but possibly-disastrous feedback mechanisms). Even if you think the climate’s sensitivity to carbon dioxide concentration is much less than what the models suggest, at some point, technology will allow us to burn enough fossil fuels to STILL dramatically change the Earth’s climate. The Earth doesn’t have quite as much carbon as Venus, but if you include all subterranean sources of carbon, it’s a lot closer than you might think.
The atmosphere of Venus is 90 times more dense than that on Earth and it is made of 96.5% of CO2 and a 3% of nitrogen. This means that both planets have the same amount of Nitrogen on their atmospheres. Surprinsingly the CO2 on Earth is stored on calcite type rocks and if we would convert the CO2 on these rocks into atmospheric CO2 it would amount to the same amount of CO2 that there is on Venus’ atmosphere.
This is why it’s critical to develop carbonless energy sources AND intentionally move away from fossil fuels: technological progress will pretty much guarantee we won’t run out of fossil fuels. The physics of CO2 insulating the planet is well-understood from the spectroscopy of gasses and fundamental physics, but the feedback mechanisms are not well-understood (if you’re going to be skeptical of the models, this is where you should look). But even if you neglect ALL feedback mechanisms, you’re still talking about perhaps 10-20 F increase in temperature plus a large increase in atmospheric circulation (i.e. weather) if you burn all this CO2. Throw in some feedback mechanisms (melting and degassing of permafrost, methane clathrates), and who knows.
Luckily, energy is everywhere. In the wind, in the water, in sunlight, in the Earth, and even in atomic bonds. We can easily find better ways to harness useful energy than burning things. And of course, we aren’t going to find another planet nearby which has vast amounts of both oxidizer and fuel, so if we’re going to expand to the cosmos, we need to solve these problems anyway. This post is to provide motivation for some later posts, where I discuss all the various ways we can produce abundant energy.