Energy and Human Ambitions on a Finite Planet(escholarship.org) |
Energy and Human Ambitions on a Finite Planet(escholarship.org) |
"Hands down, solar is the only renewable resource capable of matching our current societal energy demand. Not only can it reach 18 TW, it can exceed the mark by orders of magnitude." (Section 13.9)
"We would likely not be discussing a finite planet or limits to growth or climate change if only one million humans inhabited the planet, even living at United States standards. We would perceive no meaningful limit to natural resources and ecosystem services." (Section 3.5) An energy source that is thousands of times more abundant than fossil fuels is basically equivalent to having one one thousandth the population.
While I must acknowledge the truth that converting things to run on electricity will be a large engineering and logistical challenge, and that battery production must be scaled up (as well as converting some loads to run where the sun is shining), both of these challenges pale in comparison to the money part of that first quote: "exceed the mark by orders of magnitude." In other words, even if we could only store electricity at an efficiency of 1%, we'd be fine. (In actuality, we ALREADY store electricity at efficiencies over 80 times that.)
Ecosystem services, availability of raw materials, and many other challenges exist as well. However, all of them are meaningless in the face of "we would perceive no meaningful limit to natural resources." Having an energy source that is thousands to millions of times more abundant than the ones we use today lets us substitute energy for basically all of our needs. (Need clean water? Energy + dirty water = clean water. Need more steel? Dirt + energy = steel. Need to remove CO2 from the atmosphere? You can do it, at only the cost of several times the energy you got putting the CO2 into the atmosphere, which is only a few % of the future energy budget from solar. Think of it this way. In the past, we relied on cutting down forests for heat. Putting the forests back would have seemed like an insurmountable task, because our fuel came from the forests. But now that we run on fossil fuels, which are approximately 100x more abundant than forests, putting the forests back is a matter of politics and land usage discussions, not one of practicality.)
In other words, we are the only ones we have to blame if the future is not MUCH wealthier than the past, both per person and also for our total economy.
Regardless, I think the book remains useful for its intended audiences as a quantitative assessment of available energy sources given our growth path.
[0] "The rookie mistake here is assuming that adults are in charge." (p. 134)
Completely blanketing the Earth in solar panels gets us a few hundred years more (thanks to the fact that that solar energy is already hitting the planet whether or not we use it for electricity), but that's assuming we've developed panels with magical levels of efficiency and we're okay with 0% of sunlight reaching the Earth's surface.
Four hundred years of sustained energy growth at current levels is the most that could happen on this planet under comically-implausible circumstances, and when we reduce the absurdity even just a bit (greenhouse gases still exist, we won't blanket the planet in perfectly-efficient solar cells), we optimistically might get two hundred years more before we hit an energy wall that cannot be overcome without a complete overthrow of thermodynamics as we understand it.
Is that still a lot of growth? Sure. But it's about the same window of time as the industrial revolution until now.
> "Fusion is therefore a complicated and not particularly cheap way to generate electricity. Meanwhile, we are not running terribly short on renewable ways to produce electricity: solar; wind; hydroelectric; geother- mal; tidal."
Fusion is the key to long term success for humanity. It paves the way to essentially unlimited cheap burstable power.
In the even longer term plasma fusion offers a way to create the heavier elements that we are running out of here on earth. Forged in a manmade nuclear furnace.
These pesky climate problems can be solved. We just have to mine ideas out of nature now instead of minerals.
If you're trying to think about humanity's long term prospects fusion should be the crown jewel, not an after thought you handwave away. I believe today we spend somewhere on the order of 1% of what we should be spending on fusion research.
Brilliantly said. I believe a lot of resistance to the idea that our way of life is unsustainable stem from grief that the future that we were "promised" by the last century of media and marketing isn't coming. The first step towards adapting to the imminent collapse of the high-consumption lifestyle due to energy and resource limitations is to process this grief.
What do you think a sustainable way of life looks like? In terms of both global population size and typical life experiences.
That's why I expect we're headed for tragedy- we can't and won't collapse everyone's consumption to that level. The people who consume the least will be the most hurt by the ecological consequences of what we in the high-consumption regions of the world do.
Label the first column C for capital. This starts at 1.
Label the second column T for total resources extracted. This starts at 0.
Label the third column r for resources extracted this step.
Label the fourth column E for extraction efficiency.
Label the 5th column m for maintenance. Make it proportional to capital.
Now, for each step:
E is some positive function of T with a negative slope. It doesn't have to have a finite area under the curve (you don't have to assume total resources to be finite, in other words). You just have to assume that the next unit of resources to be extracted requires a bit more effort than the last one. Use E = .1*exp(-.01*T) or something like that.
r = C*E
m = C*k where k is any positive number between 1 and 0- .01 is a good constant to use.
C += r*q - m where q is again some constant, say .2
T += r
Now observe the behavior of the system. Plot the value of C over time. For the above constants you'll want to include about 3000 steps.
(Edit: forgot the maintenance term)
from math import exp
k = .01
q = .2
C = 1
T = 0
E = lambda T: 0.1 * exp(-0.01 * T)
for step in range(3000):
r = C * E(T)
m = C * k
C += r * q - m
T += r
print('%5i %g' % (step, C))So much so that this trivial exercise imparts real wisdom and is definitely not mental masturbation.
The issue, of course, is in step 2.
Figured this out decades ago.
rule of 70tells us that the time it will take a system or collection to double in size is 70 divided by thepercentage growth rate. The time units depend on how the time over which percentage growthis expressed—like 2%per dayor 2%per year, for instance. The rule works most accurately forsmaller growth rates, under 10%.
Actually showing 1.10^7 = 1.949 vs 1.01^70 = 2.007, so you can approximate by dividing percentage by 70 between 1% and 10% is fine. Stating it as true in the text then adding a note well no not actually latter on is problematic.
He does walk the reader through a lot of “back of the napkin” math, in order to help the reader get an intuitive sense of the models he’s using. But my impression overall is that he backs those hand-wavey calculations up with more serious calculations throughout the book.
He goes so far as asks someone to do the approximation across several hundred years of compounding. And sure it get’s a big number but one no even close to accurate.
I’m currently leaning in this direction myself. Not necessarily just this, but “big filter ahead” (or lots of small filters). Perhaps it will be this, perhaps it will be a Jonestown massacre but with entire O’Neill cylinders instead of individual people, leading to a Kardashev II scale Kessler syndrome.
The only heavy element that we actually "use up" to any significant degree is uranium, which is consumed for energy, but if we had cheap fusion energy uranium consumption would plummet. Even if we could make artificial uranium it would be a net-energy-losing process to make artificial uranium with fusion power instead of using fusion power directly.
Helium would like a word with you.
The thing is, it's not just climate that's the problem. The "pesky" problem is that we've crossed or are soon crossing most planetary boundaries[1] at the same time.
Fusion doesn't stop and reverse biodiversity loss, chemical pollutants, land-system change, biochemical flows, ocean plastic buildup and ocean acidification.
To stop the ecological collapse, the necessary condition is that the global North drastically reduces material flows and energy consumption. With less energy use, fusion also becomes less critical.
the problem is the human psique, not technological capabilities.
And you're right. We're only a bit over two hundred years away at 2.3% annualized growth in energy use from noticeably raising Earth's surface temperatures just from a thermodynamic perspective. And that's completely ignoring the effects of greenhouse gases.
No, it doesn't. The obvious cause of the huge economic growth over the past 150 years, which is what the author focuses on, is population growth. World population is expected to level off in this century.
The author also assumes, incorrectly, that GDP--money spent on goods and services--is the right measure of overall wealth. It's not. The author even discusses "decoupling", the fact that many types of wealth require little or no physical resources to produce, but fails to realize that the long term outcome of this will not be to raise monetary GDP more and more, but to make monetary GDP less and less of an accurate measure of wealth production.
Finally, the author misunderstands basic economics when he says (p. 25): "A limited life-essential resource will always carry a moderately high value." This is a common misconception. An obvious counterexample is air: air is a limited resource (Earth's atmosphere contains only a finite quantity of it), it is life-essential, but it is free. Why? Because it costs nothing to produce. And if the cost of production of other life-essential resources, like food, were reduced, those things would also become cheaper. (In fact, that has already happened to a large extent in the developed world: over the past 150 years, the fraction of people involved in food production has dropped from about 19 in 20 to about 1 in 20. The main reason food is not much cheaper as a result of this is political: governments artificially manipulate the markets for food, for example by paying farmers not to grow certain crops. This is fixable without any increase at all in our expenditure of physical resources.)
Kinda I suppose. But the whole spreadsheet 'try this' trope is already unnecessarily hostile. You could put everything that spreadsheet exercise demonstrates into words.
And that's my main argument too. This equation/exercise is so simple as to be useless.
Human systems are multi-variate to the degree that a simple equation -- in this case showing that reliance on extractables is bad because their availability exponentially increases at the same time humans exponentially rely upon them more -- does not mean much of anything in the larger picture.
This equation sidesteps human ingenuity, free market adjustments that will be made, predicted population decline in developed countries, and if the equation did apply, where on the timeline of the curve would we be.
And those are just some of the criticisms of viewing the world through such a simple myopic lens.
The third assumption, that capital increases as a constant proportion of resources extracted, is even more questionable. I think it's fair to say that we are able to do more with less now than we could in the past. You might say that that is a function of the existing capital too. So what happens if you try something like C += r*q*(1 + .01*C)? Do you still get a peak?
And of course, there's the assumption that the next bit of resources you extract is a little harder than the last bit. Statistically this has been true for some time now, but you could imagine this rule reversing, at least temporarily, if we gained access to some new resource, say, asteroid mining.
So there's plenty in the model to attack, if you take the time to really consider it.
I do realize too that my model makes assumptions- which have not been demonstrated to be true. So, that’s where I would attack it. Which assumptions are false?
I'm not saying that this applies to your arguments, but what I notice among many people and groups claiming to be concerned with our impact on the environment is more of a fetishism towards doom and pushing forward a notion of personal sacrifice for billions of people, while actively making any excuse for decrying numerous suggestions for technologies and social advancements that could possibly let us make the world cleaner while also being able to live better on a much broader scale.
That kind of thinking teeters on the verge of pseudo-religious, ideological instead of being something reasoned and practical.
Bad news, I’m afraid: If you keep the population and technology constant, the maximum sustainable consumption per person is lower than basic metabolic needs. Either the tech or the headcount needs to change, and nobody is going to let it be their head that gets dis-counted.
The main reason for this isn’t energy (current tech includes really cheap PV we just have not yet gotten around to building but could and likely will), it’s phosphorus. Phosphorus is mined for use in fertilisers, it isn’t renewed, the run-off flows into oceans.
Only thing we know of that might help is more tech, and the tech seems like it needs high-consumption societies to get proper funding.
Naturally, if you can get good research going without that, that’s a massive win for everyone, not just in this aspect.
world population is leveling off because we're approaching many of these limits to growth and that's affecting the enabling factors for continued population growth.
> The author also assumes, incorrectly, that GDP--money spent on goods and services--is the right measure of overall wealth. It's not. The author even discusses "decoupling", the fact that many types of wealth require little or no physical resources to produce, but fails to realize that the long term outcome of this will not be to raise monetary GDP more and more, but to make monetary GDP less and less of an accurate measure of wealth production.
I agree with this.
> "A limited life-essential resource will always carry a moderately high value." This is a common misconception. An obvious counterexample is air: air is a limited resource (Earth's atmosphere contains only a finite quantity of it), it is life-essential, but it is free. Why? Because it costs nothing to produce.
you conflate value and price here. obviously atmosphere is not currently metered. That doesn't mean we don't place a high value on clean air.
> And if the cost of production of other life-essential resources, like food, were reduced, those things would also become cheaper.
I'm not doing that. I'm pointing out that the author of this paper is doing that. He is assuming that everything of value is captured in the GDP, i.e., in money spent. But as you acknowledge, this is false, and that invalidates his argument.
> https://en.wikipedia.org/wiki/Jevons_paradox
The Jevons paradox does not say things don't become cheaper when their cost of production is reduced. So it is not an argument against the statement of mine that you were responding to here.
Also, if we are talking about life-essential resources like food (or air), which was what I was talking about in the comment you responded to here, the Jevons paradox is of limited applicability if it applies at all, because demand for such resources is constrained. Even if food were free, people would not eat an unlimited amount of it, any more than they now breathe an unlimited amount of air because air is free. The most important factor driving an increase in total consumption of such resources is population increase, so if population levels off, the resources consumed for these life-essential things will be naturally limited no matter how cheap they become.
Is it? My understanding is that as economies become richer, healthcare improves, infant mortality decreases and parents reduce their birth rates because they need less children to “hedge their bets”.
Also lifting everyone to the living standard of highly developed countries will require significant amounts of resources and significantly increase energy consumption, this however is also more like a one-time expense and I would therefore ignore it, too.
How does dependence on technology demand growth? Because resource extraction becomes less efficient as we deplete available sources?
actually they are generally below replacement level, which (if not augmented by immigration) would itself lead to a collapse as people leave the workforce and there are fewer laborers to replace them. But people think we manage this labor shortage with technology, which leads us back to the requirements for more energy and capital development to maintain the same lifestyle.
> Also lifting everyone to the living standard of highly developed countries will require significant amounts of resources and significantly increase energy consumption, this however is also more like a one-time expense and I would therefore ignore it, too.
why do 'highly developed' countries need vastly greater resources to maintain this living standard if its a one-time expense? the greater standard of living your referring to requires continually expanding quantities of inputs in terms of energy and labor, aka 'economic growth'.
> How does dependence on technology demand growth?
its more related to the specific technologies we've chosen to build our society upon, but this technologies generally depend on these improvements to sustain themselves. For example, electric cars require batteries which require raw materials to be mined, recycling batteries requires chemical industry that is predicated on all sorts of inputs, themselves coming from nonrenewable sources.
There are literal physical limits here that can't just be handwaved away by space magic. Higher energy use in a finite spherical volume fundamentally results in increased temperatures when your only way of getting rid of that heat is radiation (and not convection or conduction). And we can't just beam that heat away with space magic either thanks to entropy.
Thermodynamics gives us no tools to deal with this problem outside of increasing the spherical volume of Earth (and therefore its surface area).
Which is extra good as this offsets other parts of the world. I would also guess that it is probably easier to provide incentives for people to have more children once this becomes necessary than trying to prevent them from having too many children, but that is not much more than a gut feeling.
But people think we manage this labor shortage with technology, which leads us back to the requirements for more energy and capital development to maintain the same lifestyle.
If we permanently fall below replacement-level fertility, we will just die out and no amount of investment will fix this. The only solution is to match replacement-level fertility which will provide a stable population and workforce and hence require a stable amount of economic activity to achieve a stable lifestyle. The obvious caveat is of course that the economic activity must not deplete any non-renewable resources.
why do 'highly developed' countries need vastly greater resources to maintain this living standard if its a one-time expense? the greater standard of living your referring to requires continually expanding quantities of inputs in terms of energy and labor, aka 'economic growth'.
The one-time expense is to lift someone from say 2,000 kWh/a to 40,000 kWh/a which requires adding the difference in production capacity. After that this person will of course consume 40,000 kWh every year and we will have to produce those 40,000 kWh every year, but I don't think that constitutes economic growth. Economic output is quantified as absolute output over some period of time, not as cumulative absolute output.
For example, electric cars require batteries which require raw materials to be mined, recycling batteries requires chemical industry that is predicated on all sorts of inputs, themselves coming from nonrenewable sources.
I still don't see how this requires continued growth if we assume constant output.
A world where energy consumption increases fiftyfold is a century and a half away and would be brushing up against the point where we are noticeably increasing the equilibrium temperature of Earth sans any greenhouse gases. Hitting the thermodynamic limits of Earth's ability to radiate heat into space isn't a far-fetched fantasy, it's terrifyingly close.
Edit: Also, your numbers are quite simply incorrect. The 70% of sunlight that doesn’t bounce back into space is about 35,000TW, far from the hundreds of trillions of terawatts you claim. At 2.3% energy growth for the next 275 years, we’ll be adding 7,000TW to this number. That is easily enough to noticeably increase Earth’s equilibrium temperature, and far less than this will be necessary to do so given greenhouse gases which reduce our ability to radiate heat into space.
The Earth receives 340 W / m^2 on average (not accounting for albedo) [1]. The surface area of the Earth is 510 trillion m^2. Humans release 160,000 TWh / year (18.5 TW) [2]. That means the input power from the sun is 9350x what humans release into the atmosphere. If wind and solar play a larger role in the energy mix then the picture looks even better. I can't see how humans could increase power consumption by multiple orders of magnitude without solving so many other (more difficult) problems. Even if we did, playing games with albedo and/or orbital sunshades are on the table with the comparatively meager means we have today. Any future society using that much power surely could address these issues with ease.
Also, expecting constant growth for the next 275 years isn't really a good projection of current trends. We're already seeing negative 2nd derivatives in energy production and population. There is nowhere left to expand in to. The world has become very small very fast.
1. https://earthobservatory.nasa.gov/features/EnergyBalance/pag...
The whole point of this debate was that fusion will not unleash a new era of unlimited cheap energy. My argument is that not only will it not, it can not. Will we have more energy available to us than before? Certainly. But all it will do is push us closer to fundamental thermodynamic limits of the Earth's ability to radiate excess heat into space.
Replacing 18.5TW of current power generation with 185TW (10x!) of fusion capacity will already start putting us frighteningly close to those limits. 10x on top of what we have today sounds like a lot, but nearly 90% of the global population today lives in poverty. Bringing them up to a developed-world standard of living will likely eat up well over 100% of that additional budget. Can we augment that with solar? Certainly! But this is hardly "unlimited" energy. A 10-fold increase in energy output will buy us maybe 150 more years of growth.
You may not be happy with it it, but this is the graph of Earth's equilibrium temperature given a consistent 2.3% annual increase in (non-solar) power generation:
https://dothemath.ucsd.edu/wp-content/uploads/2011/07/tmp.pn...
I encourage you to run the numbers yourself. They are correct. And this is treating the Earth as a perfect blackbody which it is not. These numbers are worse when you consider greenhouse gases, even if we manage to somehow go back to pre-industrial levels of carbon in our atmosphere.
