Sustainability, ethics, and the needs of future generations

When people speak of sustainability or sustainable development, they almost always use the Brundtland definition of sustainable development, being human development which

"meets the needs of the present without compromising the ability of future generations to meet their own needs"

Leaving aside the question of what is meant by development and whether such a thing can ever be sustainable, long term, a couple of things occurred to me in reading through the latest batch of assignments from my final year chemical engineering students.

One of the central concerns in sustainability is that our behaviour affects others: in different geographical areas, but also in time. Recognising that it's appropriate to consider the interests of these others in choosing our own behaviour, is recognising that sustainability questions are fundamentally questions of ethics.

Now ethics can be tricky, but one of the really important principles in doing the right thing is the idea of informed consent. Make sure that the others who will be affected by your choices are sufficiently aware of what's at stake to understand where their own interests lie, and then listen to their views before deciding what to do.

The big problem with considering the interests of future generations is that they don't exist yet, so we can't have this conversation with them. We are left with the much less satisfactory alternative of imagining what it would be like to be the future generations and making the choices on the basis of a set of assumptions about them. What makes this especially problematic is that we don't know who these people are and what their needs are; and the further we look into the future the more of a problem this becomes.

Let me give you some examples of what I mean.

What if the future features unlimited technological growth?

The 20th Century saw remarkable human progress on many measures. It is easy to think (and indeed many people think) that this progress will continue. Cancer will soon be cured, we'll all have flying cars and there will be a colony on mars. After that, who knows? Probably an interstellar society linked by spacecraft with warp drive propulsion or something even cooler than that! Things we can't even imagine now!

What will the needs of these future people be? What should we do today, if we feel a need to be fair in balancing their needs with ours? This is a very difficult question. Technology can seem like magic, making essentially anything possible. With unlimited technological progress, it looks like we don't need to worry about future generations meeting their pysiological needs. Possibly we should preserve parts of our ecosystems and some of our old infrastructure for sentimental / cultural / historical reasons. The future generations might like to visit the cradle of their species from time to time, which will help meet their need for a sense of identity and history.

What if the future is only a bit more advanced than now?

With some understanding of physics and biology we come to understand that some things are not possible and will never be possible. The warp drive will never happen. The colony on mars looks unlikely - technologically possible (maybe), but very, very expensive and not a pleasant place to live. We might suppose that progress will continue, perhaps at a slower pace than now (as a worst case scenario). We understand that technological solutions to problems are expensive, and that more difficult problems entail more expensive solutions.

How do we balance our needs with those of these future generations? They will have a more advanced society than ours, with clean energy, low levels of pollution, recycling and re-using all of their materials - a "circular economy". To look after their interests, we should be careful to not damage the natural environment too much, so as to not burden them with too much in the way of clean-up or adaptation measures. We should not make valuable resources difficult or impossible to recover.

For example, helium has very particular technological uses (mainly cryogenic cooling - nothing else can cool things down to 4.2 Kelvins like helium can). Future generations might need this ability for their technologies, so we shouldn't carelessly allow this non-renewable resource to escape into the atmosphere. When we do, it quite quickly floats to the top of the atmosphere and escapes into space where it is gone forever. Similar story for phosphorus. It's essential for life, not renewable, and not substitutable by anything else. It can be recycled (and is recycled naturally - very slowly) but if we keep flushing it into the ocean, that makes things more difficult for the future generations because it becomes extremely dilute (read: expensive to recover).

With a future like this we can probably delay immediate action on some of our trickier problems because they may become easier to deal with in future. For example, almost none of the spent nuclear fuel we have produced over the last 70 years of nuclear power generation has been secured in long term storage. It is mostly held short term (years) in special cooling pools or in intermediate term (decades) dry cask storage, both of which require active technical and security management. This is probably reasonable because the future generations will have better disposal technology than ours, but also because this waste product might be a resource in this future. Breeder reactors, for instance, might be made safe and economical, allowing future generations to burn up and make safe our waste, generating a large amount of energy in the process.

What if the future is less advanced than now?

This can be hard to imagine. It's quite literally an article of faith for most that technology only ever improves, or at worst, remains static. That society "improves" with time - education standards go up, as does wealth and life expectancy with improved medical technology, more enlightened public policy and decreasing inequality and violence - is taken by many as a given. That's been the experience of most over our lifetimes, the lifetimes of our parents and grandparents.

That's been our recent experience, but there is no law of nature that makes it so.

Historically there are plenty of periods where all of these things go the other way. Technology is lost, literacy becomes uncommon, the economy contracts along with the population, often along with a rising spiral of political violence. 

It's called social collapse.

It happens to almost all societies, every 200 to 400 years or so. It happened to the ancient Greeks, the ancient Romans, the ancient Egyptians, the Harappans, the Mayans, the Greenland Norse, the Chinese (multiple times), Vietnamese (multiple times), Easter Islanders - it's a really long list. It generally happens when complex societies grow up against resource limits. They become complex in order to use resources efficiently, but it requires a lot of effort. The burden of the effort falls primarily on the lower social classes, for whom life becomes more difficult as real wages fall. This leads to enrichment of the elite social classes, but loss of tax revenue for the state. The state becomes unable to enforce peace between increasingly combative elite factions. Internal conflict and a weakened state make the civilisation vulnerable to disturbances like natural disasters, external aggressors, climate change, etc. Any number of events can be the final push over the edge that starts decline, but the internal social dynamics put the civilisation in a weak and vulnerable position in the first place.

If you're the type that takes notice of these things, you'll have been seeing the warning lights for these things blink on one by one as our modern society walks into the same situation that all the complex societies before ours did. We are hitting resource limits. The economy has stopped growing. We have stagnant wages, falling birth rates, falling tax revenue, economic (GFC) and political (Brexit, Trump) instability. Climate change. Increased political violence. Check, check, check, check, check.

This isn't the point yet, but we're getting there.

Suppose that social collapse happens to us, at some point. Based on the evidence, it's very unlikely that there will be a global industrial society anything like ours, 100 years from now. Even for the next 50 years, it's looking pretty iffy.

Now we're at the point: future generations maybe only 100 years from now are quite likely, the way things are going, to have less technological capability than we do, not more. This is not to imply that our great-great grandchildren will be living in caves and hitting each other over the head with rocks. What we will probably have are societies less globalised, with fewer people than now, using simpler technologies that are easier to sustain. 

They won't have a use for spent nuclear fuel, but they will certainly be harmed by it if we don't make it safe in deep long term storage while we're still able to. 

It's also likely that they won't have any use for helium, so as a sustainability issue we can probably stop worrying about that  one. Only advanced technological societies need helium.

What they will need is a functional ecosystem they can grow food in, free from poisons that will cause unnecessary suffering. 

What we imagine in the future, affects our ethics in the present

So, what we imagine things will be like in the future, affects our ethical calculus in the present quite a lot. The technological views of the future seems to explain quite a bit about the things that people worry about on behalf of future generations. The high levels of concern on preserving pockets of ecosystem beauty, and the rather lower levels of concern for broad ecosystem function. The high profile of space research including searching for Planet B and the limited work on cleaning up the messes we've already made (and continue to make) on Planet A.

To be ethically competent we need to think about a range of realistic probabilities for the world that future generations will live in, and what their needs and capabilities might be. Not just accept without question the narrative than mankind is destined to ever greater achievement. That can give us a dangerously distorted view of what future generations' needs might be.