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Earth: Priceless

Christmas is the season when prices, costs and value are on everybody’s mind. At least when trying to estimate how much a present is worth to a friend or family member (and the value of our own happiness at their happiness): is it really worth the price in the store? Lee Billings recounts a fascinating discussion with the astronomer Greg Laughlin and natural capital expert Taylor Ricketts about How Much Money Would an Earth-Like Exoplanet Really Be Worth to Us? A closely related question is of course: what is Earth worth?

The price is right?

Greg Laughlin once developed a valuation formula based on solar mass, planet mass, temperature, age, visibility etc., calibrated by the land price of the 1803 Louisiana Purchase. Applied to Earth it gives a price of 5 quadrillion dollars, which is about 100 times the Earth’s current yearly GDP. This was largely an ad hoc estimate to show how valuable exoplanet searches could be rather than an attempt at estimating the real value of Earth.

Robert Costanza et al. estimated the value  of the world’s ecosystem services and natural capital in a 1997 Nature paper. They concluded “For the entire biosphere, the value (most of which is outside the market) is estimated to be in the range of US$16–54 trillion (1012) per year, with an average of US$33 trillion per year. Because of the nature of the uncertainties, this must be considered a minimum estimate.”

This estimation is very much based on instrumental value: the value the ecosystems have to us, and what we are willing to pay to sustain them. Costanza et al. also clearly point out that there may indeed be moral values that matter, but they represent different sets of dimensions and languages of discourse that make them hard to make valuation and choices. Measuring ecosystem service value in dollars is far likely to convince politicians than a lecture on just how much human dignity is embodied in a proper relationship to nature.

In the following I will be more interested in some form of moral value than dollars, but there is some benefit in remembering that economics is about reasoning under scarcity. If something is ubiquitous we rarely have to consider its value. But Earth seems to be unique.

Infinitely valuable?

One could argue that Earth is unique, and hence infinitely valuable. But there are many unique things that are worthless – unless I am Andy Warhol I cannot sell the contents of my trash-can, despite that this configuration of objects never having occurred and never will recur across the span of universal history.

In Billing’s discussion the claim was made that the proper value of the Earth is infinite since without it we cannot exist.

But this claim has some problems.The world might not have enough money to pay for a replacement Earth, and we might be willing to pay all our money or resources to save ourselves and the planet. But if we truly believed the value was infinite we would never take any actions we believed had any chance of ending the planet. I am not just thinking of people’s revealed preferences in environmental matters (but then again, such revealed preferences often suggest we place a rather low value on our own lives) but also existential risks – people seem far more gung ho about setting off potentially risky physics than an infinite value would imply.

Another problem is that this value is tied to us. Yes, the Earth may be essential to us, but if we did not exist that value would merely be undefined. It is a very similar case to the Lucretian argument that death is not a problem, since when we are dead we do not exist and cannot be harmed. We could just claim Earth’s present is infinitely valuable to us, but not the future after us (the past might also be valuable, since without it we would not exist).

However, one might argue that there is intrinsic value in the environment. There are animals that likely value their existence to some extent, and environmental ethics has discussed whether ecosystems or even abiotic environments have an intrinsic value. But it is not clear that this value becomes infinite: yes, each individual being needs the world to survive and would rationally (if they could) sacrifice value up to their own lives to maintain it, but there are just a finite number of beings. Humans are slightly unusual in that we can foresee vast futures and have preferences over them: we might actually be willing to give up more than animals in order to bring about fantastic futures for our remote descendants. In fact, some such preferences might mandate that we sacrifice the current world for a future, far better world.

Billings also brings up the problem that there are hierarchies of infinities – some things are more important than others, despite being immeasurably important. Preventing the extinction of ten species might not be “numerically” different from preventing the extinction of one species, but it has priority. One value such as human dignity might have priority over another value such as the value of an ecosystem. Here we might end up quarrelling about what values have priority or even whether it is possible to determine. Some systems might find the end of the world preferable to some outcomes (“Fiat iustitia, et pereat mundus”?)

Best used before year 1 billion

Laughlin points out that in the long run the Earth will go away anyway because of the Sun’s expansion into a red giant. So there is only a finite number of habitable moments to go around. Of course, he also points out that we could move the planet using the right technology. That actually leads to a cost calculation: how much effort and risk would it be worth to save the planet?

Some commenters at Io9 think the question is pointless since a civilization able to do such things must surely be a post-scarcity society. But it would still be bound by the laws of physics, having only a finite amount of matter, energy and time available, and these things could be used for many different desirable  aims: opting to do one thing precludes others, and the economics of opportunity costs would be relevant.

Of course, we might apply economic discounting to the future value of Earth. As have been noted in the discussion about climate change, this typically cuts off most of the future. Even with just a 0.1% discount rate anything happening beyond a thousand years into the future does not matter. So the total present and future value would be something like the total annual value of Earth times a few hundred. As John Broome has argued, maybe discounting is the wrong thing to do for something that isn’t a commodity (like welfare). This might well apply to the value of the world too: inherent value likely doesn’t discount, and if there are future people valuing the world they will of course not value it less because they are far away from us.

One way of estimating value is to compare what the energy needed to move the Earth could be used for. The move would require 8.7 × 1032 joules of energy, which is about 26 days of current solar output. Using the estimates in Nick’s astronomical waste paper we get a rough estimate that an advanced civilization could run 1025 human-like minds at human speed using solar output; losing 26 days of that would be 7 × 1023 person-years. For comparison, there have been about 100 billion people ever and if they all lived to 50 that means human history so far is just 5 × 1012 person-years. I have no idea if that means Earth is better used as raw material for a vast posthuman infrastructure or whether those beings would value it so highly that they would undertake a project costing more than all of current human history.

How much, earthling?

Elon Musk estimates a Mars colony program for $36 billion. He is at least partially motivated by a desire to reduce existential risk which would presumably make nearly any price worth taking, but one could of course argue that if the 80,000 colonists split the planet each would get 1809 square kilometres each to play on (slightly less than the area of Mauritius). Still, the project might not necessarily be a good deal; using Laughlin’s formula I get a Mars price of just 28 billion dollars.  The real problem is of course that Mars is cold and barren: while it would be great to have somebody live there permanently and some value in learning and experiencing this unique world, it lacks a lot of what makes Earth valuable: its life, its history.

Imagine that aliens arrived and asked to buy Earth. What price would be worth it?

It seems likely we would not accept any price lower than having somewhere else to live. This is the instrumental value of Earth to us. Most likely we would also want the parts of the biosphere we value for their own sake to get somewhere to live. So the aliens better give us at least another habitable exoplanet.

But many would likely argue that there is plenty of value inherent in Earth being Earth – our old home, where our species evolved and had its history. To some this is not just affection value but something deeper: consider the reactions of people in Israel if somebody suggested they sell off the Promised Land – it has a particular kind of relational value at the very least between people, and according to many, between the people and God. You don’t sell your Christmas presents from people who love you, since they are gifts that entail certain obligations given your relationship (so at least you will not tell them what happened to that hideous sweater or painting).

Even if one does not view the world as a literal gift from God, one could argue that we have a relationship with it that is special in a similar way. We evolved here, as a part of the world. Even if the world is not a person and we do not have a social relationship to it, we might have acquired obligations to past and present entities. Ancestors wished their descendants to have good lives of  particular kinds (we tend to remember fondly those who we think wished for lives like ours, rather than their real wishes – I think we should be happy to disappoint selfish, bigoted and xenophobic ancestors). We have reason to be grateful for much of what they did and to some extent respect their wishes just like we hope the future will respect our wishes and think we have improved it.

So while I do not think the value of Earth is arbitrarily high, it is high to us. Maybe not to each individual; I can imagine both holdouts arguing that we must not sell the planet at any price and people thinking they would be better off if they got a Mauritius-sized piece of land. But there is a relational component to the messy emergent order that have evolved on this planet that persists over time, and since this order involves value-experiencing and social animals, some of which stretch their minds over vast ranges of time, we do have an obligation not sell off the planet too lightly. Conversely, if we want to buy the alien’s planet, we should be ready to pay a lot – it is probably better to terraform a new one rather than try to get a family heirloom.

In the end, a good present is not expensive but has plenty of meaning. At least this is what I will tell my family when they get their presents.

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3 Comment on this post

  1. Fascinating post. I think I see nature more negatively than before because of wild-animal pessimism (suffering and victimization).

    Imagine that aliens arrived and asked to buy Earth. What price would be worth it?

    It seems likely we would not accept any price lower than having somewhere else to live.

    Unless we get the compensation now and the aliens get the planet later. An interesting thought experiment could be this:

    Non-scary aliens arrive and politely offer us safe energy, goods, services expressed in dollar value, evenly distributed for all humans. There will be a vote, and if the majority agrees, humanity gets these gifts but in return, all human children born from now on won’t be able to have children of their own, and once the last humans lived out their natural life-span (with robot care for the elderly), earth is destroyed to make way for an interstellar art project.

    How many dollars would each human have to be offered for the majority to vote yes, assuming no coercion and secret votes? I think the answer is probably lower than most of us would think.

  2. I think there is a huge diminishing marginal return on Earths. Given that we do not currently possess the ability to live outside Earth, its values should be somewhere near the dis-value of an existential catastrophe. We should sell Earth if completely trustworthy buyers promised to simulate more than around 10^53 lives (times our subjective probability of no-doom if we don’t sell) elsewhere. But I think asking this question for civilizations with just one planet and without ability to live elsewhere might be meaningless, it will always be sort of “priceless”. Another more down to Earth (but still pretty far-fetched) calculation of Earth’s value is how much we should invest on colonizing another Earth, should we find one within our reach. This would perhaps be equal to the value of the existential risk reduction of having two planets. Yet another way of putting the question is how much we would be willing to pay to expand/reduce Earth’s surface. Either way, the value should be many, many times higher than the world accumulated wealth. So basically Earth’s value is “everything he have”.

    Another question is how much a random advanced alien civilization would be likely to pay for an Earth. I think this would depend more on Earth’s mineral composition than Earth’s capacity for life. Presumably, a really advanced civilization will find easier to terraform close-by planets than to find and buy habitable planets – they would probably won’t need to buy anyway. It seems Iron would be one of the most valuable elements, so Earth does not seem particularly valuable. Or it might be that intelligent life is some sort of cosmic diamond, extremely hard to find and costly to make. In that case Earth’s price would be really determined by how much humans we would be willing to sell with it. But this seems unlikely.
    Overall I think we are much more likely to have to buy another Earth (through terraformation or space exploration) than to sell ours, which is convenient since calculating the price of just one Earth seems way trickier.

  3. Before we start: I’m most amused that Nick Bostrom has done an energy / entropy version of the infamous Basilisk nonsense. Notes from the peanut gallery: it doesn’t work like that. ‘Singularity’ is not your friend, and it certainly isn’t through the eye of a binary field. (cf Conceptual Identity with Perfect Language – dominant AI problems)

    Old question:

    Q: What is the price [value; sic] of an egg?
    A: Whatever the buyer will pay for it.

    Now, is that an egg that can hatch a chicken, or an egg that is sterile, and doomed to the plate? A precursor to the ‘teach a man to fish’ parables, but contained within it is the same ethical question.

    What you failed to note in this essay is the function of systems, and indeed, time. A quick look at the paper evaluating the ‘worth’ of the planet:

    We must begin to give the natural capital stock that produces these services adequate weight in the decision-making process, otherwise current and continued future human welfare may drastically suffer. We estimate in this study that the annual value of these services is US$16–54 trillion, with an estimated average of US$33 trillion. The real value is almost certainly much larger, even at the current margin. US$33 trillion is 1.8 times the current global GNP. One way to look at this comparison is that if one were to try to replace the services of ecosystems at the current margin, one would need to increase global GNP by at least US$33 trillion, partly to cover services already captured in existing GNP and partly to cover services that are not currently captured in GNP. This impossible task would lead to no increase in welfare because we would only be replacing existing services, and it ignores the fact that many ecosystem services are literally irreplaceable.

    That’s not saying what you claim it does in your piece.

    The claim is far more drastic: that $33 trillion is the ‘cost’ of taking the planet for granted, and is already priced into our economic models as a hidden (“free”) benefit. i.e. if you break it, that’s the cost to replace something that is being broken as we speak, and that cost is greater than the current global GDP.

    Ethically, there’s a world of difference in the two positions. So, no, this isn’t an instrumental cost to us – it’s an attempt to define in economic terms the ‘free commons’ that your species takes for granted.

    I’ll not go into wider concepts about systems, biology (if I were you, I’d look into cutting edge research on just how much your gut fauna controls your ‘will’ / self if I were you, start from the mico internally then start working outwards, you’ll be surprised) and Time, as you’ve failed a very fundamental conceptual hurdle almost immediately.


    Get some Deep Green in your life. *cluck* … and Happy New Year.

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