Human beings may recognise the debt they owe to their forebears. We may even understand our interdependence to those who live on the other side of the world. But what about those yet to come? Marek Kohn explores the question of our intergenerational duties.
To do right by the future, one has to be able to imagine it. What will the world be like in 2100 and how will it be shaped by choices made today? What will it be like in 2200, or 3000; and how on earth can we work out what our responsibilities, if any, are to people living so many centuries from now? The farther the horizon, the more the scene whites out. Even the trustiest moral compasses are useless.
These questions are as pressing as they are elusive. Scientific projections indicate that human activities risk changing the climate and the planet’s ecosystems in ways that could be catastrophic and irreversible. If greenhouse gases cause the temperature to rise by several degrees, it may stay that way for many centuries, while the seas rise inexorably as they warm and expand. To avoid that risk, carbon emissions must be drastically reduced over the next few decades, which means taking strategic decisions now. Choices made in the next ten years could shape the world for the next thousand years.
Put like that, they sound like a moral imperative. But the trouble with the future is that it’s impossible to assess the risks or balance the costs and benefits. Rising seas will force people to retreat from the low-lying coasts on which many of today’s great cities are set. But will sea communications be as important to people in the future as they have been hitherto? Will future generations not devise technologies as impossible for us to foresee as the internet was a couple of generations ago?
Will the compound interest of economic growth not make our successors rich beyond our dreams of avarice? Do we owe them anything more than what’s left over from what we spend?
Some of the costs we risk imposing on them are relatively easy to identify, whether these are material losses such as that of coastal land or aesthetic losses such as the transformation of a landscape or the disappearance of familiar wildlife. Even if we disregard the possibility that these will not be considered as costly in the future as they look now, however, our moral obligations are not self-evident. Costs for the future generations have to be weighed against benefits for the present, and the latter’s claims are weighted by being actual rather than potential.
The deeper problem is that generations not yet born are themselves potential rather than actual. We cannot know who they will be; indeed, as the philosopher Derek Parfit has argued, who they will be will depend on our choices, as different actions will bring about different circumstances that will lead to the creation of different individuals. Whoever they are, they will not be able to negotiate contracts with us or reciprocate any good we do them. Reciprocity is what makes human relations go round; but we are stuck with the fact that posterity will never do anything for us.
Thus neither scientific projections nor ethical reasoning offer us a secure basis for establishing our proper relationship with the future. But the science warns us that we risk pushing many of the Earth’s great ecological and physical systems beyond their limits, and driving a significant fraction of living species to extinction. Future generations may need those species; and those species certainly need future human generations. Our cultural traditions do not lend themselves especially well to arguments that nature should be protected for its own sake, despite strongly promoting the intuition that it should. So we use the interests of future humans as a proxy for the interests of the planet. It’s not rigorous, but it’s right: we shouldn’t just write off half our fellow species because we’re struggling to spell out why not.
Nor should we give up on future human generations because we cannot specify our obligations to them. Given a degree of ingenuity and goodwill, it’s possible to draw the interests of future generations into present projects. The new Sir Leo Hielscher Bridge in Queensland, Australia, has been designed for a life of 300 years, on the grounds that a structure that does not need to be replaced for so long is good value for the community. Without painful ethical wrangling, this large but otherwise unexceptional civil engineering project has bound distant future generations into a contractual relationship with the present.
It may also be possible to tap into the power of reciprocity by linking the present with the future on one side and the past on the other. The reason that reciprocity makes the world go round is that it can be indirect: you do something for me; I do something for somebody else, and so on. Reasoning that a sense of obligation to past generations might encourage people to ‘pay forward’ to the future, Kimberly Wade-Benzoni, a professor of management, got students to advocate higher levels of fuel taxes by emphasising the taxes previous generations had paid. What we are prepared to do for the future may be influenced by what we believe the past has done for us.
There are, of course, future generations that can reciprocate what we do for them: our children and grandchildren. Not only are they the one element of the future people can be relied on to care about, but they are also the one element that people can readily imagine. We know our children, so to that extent we know something of a future that has our children in it. If we act with their future in mind, they may be encouraged to do the same for their children, and so on; saving the planet one generation at a time.
We may also find it in ourselves to generalize our concern for the next generation. You can ask the question ‘What kind of world are we leaving for our children?’ even if you aren’t actually a parent yourself. But if we do opt for a strategy that seeks to hand responsibility from one generation to the next, we still have to acknowledge that generations in the distant future may be living with the consequences of our actions. It’s the least we can do for them.
Marek Kohn's most recent book is Turned Out Nice: How the British Isles will Change as the World Heats Up (Faber).