Installation by Brian Nicholson, Coleshill (click on image to enlarge)

We pave over green areas and increasingly pollute the natural systems on which we depend.Not surprisingly, species extinction rates are at levels not seen for millions of years. Meanwhile, the human population is projected to swell to 10 billion by 2050, and after that, who knows? It is not clear that a world with a warming of 3ºC could sustain even the population projected for 30 years' time. It seems certain that we will face a very difficult time if we do not soon radically change course.

As a result, we have a number of protest groups trying to make us realise how serious the situation is. They want us to use our votes to get governments to avoid the inaction that would lead to such a disaster. And, of course, the main argument against burning fossil fuels and destroying ecosystems is that it will cause harm to future generations. All the protesters are therefore telling us that they are acting in the name of those generations. This is, however, a claim that is in fact difficult, if not impossible, to justify.

Not only for pragmatic reasons among those of us who do not have children, but philosophically, it proves surprisingly difficult to explain what exactly would be wrong with bequeathing an environmental disaster to future generations. The roots of the problem were identified 30 years ago by the British philosopher Derek Parfit in his book ‘Reasons and Persons’. He pointed out that, identity, the particular person you are, is a precarious thing.

Even minor changes in your parents’ behaviour or environment before your conception would almost certainly have resulted in someone else’s birth rather than your own. I sometimes wonder at the chance which brought me into being. How was it that the particular gametes from my parents which combined to produce me were not other gametes which might have combined to produce someone-else? Perhaps a later or earlier romantic night may have produced someone younger or older, taller or shorter, or perhaps Pauline instead of Paul. Certainly I would not have existed. It's a bit like the effect on the future of a time traveller going back in time and interacting with his predecessors. It would take so little to have a major effect on subsequent events.

Similarly, if we made the massive changes to our lives necessary to avoid foreseeable environmental damage, it is very likely that the lives of the future generation we are apparently trying to protect would not improve; in fact, most of them would not even exist.  So then in providing their replacements with a better life than the never to be born generations would have had, we make a far-reaching decision. We decide, for those who would otherwise have been born, that their lives would have been so unbearable that it would be better for them never to exist. Which, ironically, is the same reasoning used by eugenicists to prevent certain categories of humans being born. A rather strange concept.

So then, do future generations have a 'moral' right to our preventive action? Given the difficulty of knowing whose interests we should prefer, perhaps a different approach is needed. Parfit himself came to the conclusion that there must instead be a “duty of beneficence” that simply requires us to bring about as much good as we can in the world, irrespective of who exists in it. The great advantage of a duty of beneficence is that it tell us that we ought to protect the environment, because a stable climate and rich ecosystems make for a much better world than the one we are currently destined for. But, we are still left asking for whom we are trying to create that better world.

And then there is a problem with a general duty of being kind to people: it tends not to be a very powerful motivator. The suggestion that we should try to improve others’ lives doesn’t have much of a following. The avoidance of deliberately causing actual harm to people however is quite motivational, and most people will go out of their way to comply with it. Murder, for example, is a great deal less common than a failure to donate to live-saving charities, although the end result may be the same. Thus we find ourselves faced with a dilemma. We can’t appeal to future generations’ rights against harm to explain why we must change course now because, in order to prevent harm occuring to the people actually born in the future, we have to destroy the existence of those who would have been born in the absence of our meddling. Yet appealing to general duty of beneficence to others doesn’t give us much motivation to act. Is there a way out?

My view is that, as a species which mainly acts in our short-term interest, the principal reason for trying to prevent future disaster is the interest of those alive now, including me; particularly me. As a species, we are already instinctively committed to ensuring that we and members of our family, whether immediate or extended, have a good future. We do not need to know who those people may be: it is sufficient that they have, or will have, a genetic link with us. And then there are our friends or partners. We would be upset if our actions or their lack caused harm to them or to their families.

Mainly, though it seems to me that my motivation is me.  I have no wish to contemplate spending my final years in an increasingly dangerous and chaotic world. What I would prefer is to have a society which could look after people such as me. I accept that it means that I will have to make some sacrifices in order to stop the world’s climate going completely awry. There remains the question of how far I am prepared to go but, in principle, I am on board. I am happy therefore also to support financially the endeavours of medical researchers and other scientists who aim at the improvement of the human condition, even though I understand that the goals towards which they are working may be attained only after I myself am gone. Of course, I hope that they’ll get on with it to produce what I need when I finally need it.

But we also engage in activities which have no immediate physical benefit to us, but which give our lives meaning, such as the practices of philosophy, literature, sport and religion – well some of us engage in some of them. We engage in activities which we find interesting and which, mainly, we see as tying us in to the common humanity of the past and which we can imagine going on in the future.

The side-effect of this is that they in fact help to transmit knowledge, traditions or achievements across generations. The unspoken value of these endeavours in fact depends on the expectation that humans will survive long after we ourselves are dead. And so I suspect that we depend emotionally much more than we may realise on the survival of humanity far into the future – and not just its bare survival, a depressing thought, but its survival under conditions that enable it to flourish and carry on the traditions that give our own lives so much of their meaning and purpose. We want our lives and the lives of those around us to go well, which means we want our pursuits to be meaningful and the things we care about to survive.

Perhaps sub-consciously, therefore, we depend on the well-being of future generations to make worthwhile much of what we do and care about, even if we won’t be around to appreciate it.

So then, if we do nothing about climate change, we ourselves have much to lose. It will undermine the ability of future generations to secure much of what makes our own lives meaningful. And we find the prospect of that likely lack of meaning difficult to accept. We cannot easily align ourselves with the nihilism of Louis XV when he said to Mme Pompadour: ‘après moi c’est le déluge’.