wager could only be checked in the afterlife, whereas it will be possible to check our wager here on earth relatively soon, since the vast majority of those who currently inhabit our planet will still be alive.
I shall therefore consider the two principal reactions to climate change — the inadequate and then the adequate one — and try to imagine the consequences each of them would entail.
The first hypothesis is that no major step change occurs. Some countries make efforts to limit their greenhouse gas emissions; others react more half-heartedly with no more than cosmetic measures, so as to avoid appearing to be bottom of the class. Still others do nothing at all, for fear of harming their economic activity or upsetting their consumption patterns, and therefore continue to pollute quite happily. As a result, the concentration of carbon dioxide in earth’s atmosphere keeps rising.
On this reckoning, where will the world be in thirty years? If we believe the majority of scientists, as well as the United Nations and all the international organisations which keep sounding the alarm, we will be on the brink of apocalypse, because we will have passed the point at which we can prevent our planet from running totally out of control. Without going into too much detail, I shall limit myself to signalling two pieces of evaluation data which strike me as particularly worrying.
The first is that the rise in the planet’s temperature, which is a consequence of the greenhouse effect, will cause the evaporation of water from the oceans, which in turn will increase the greenhouse effect. In other words, we could enter a vicious circle of warming which will no longer be dependent on anthropogenic greenhouse gas emissions, but will accelerate by itself and become virtually impossible to stop. When do we risk reaching this tipping point? Opinions vary, but some think that it could kick in as early as the first quarter of this century. What is certain is that the longer we take to react, the more painful and costly the efforts we shall have to make.
The second piece of data, which points in the same direction, is that dramatic climate events may happen very suddenly, much more so than is currently thought. By way of example, it is thought today that the last swing from a glacial to a temperate period, which took place around 11,500 years ago, happened not by a slow process over centuries or millennia, but suddenly, in no more than a decade. Moreover, numerous scientists who have been studying climate-related phenomena for decades have been constantly surprised by the rapidity of changes, which often go far beyond the forecasts of what was thought plausible. All of which means that we must not imagine that everything we are talking about will not have consequences before the end of this century or into the following ones. We really cannot tell, and it would be wise to start preparing immediately for the worst-case scenario.
In thirty years — I am sticking to this figure so as to remain within the framework of a period which is meaningful in terms of a human lifespan, and which allows my generation still to speak of ‘us’ — we may not have witnessed all the changes which loom on the horizon, but we will already have had some devastating examples. And more seriously, the whole of humanity will have to endure a state of emergency for decades and the imposition of heavy sacrifices which will be difficult to bear without even the assurance that we can still prevent our descent into the abyss.
What if the majority were wrong? What if the future vindicated the dissenting minority which rejects the cataclysmic forecasts, mocks their alarmism and questions any link between our gas emissions and global warming; and which sometimes does not even believe in the reality of global warming, reckoning rather that we are witnessing natural temperature cycles which oscillate down then up, then down again, for all sorts of reasons which depend much more on the sun’s activity than humans’?
Once again, I am not qualified to refute these arguments and I want to suppose here that they could turn out to be true. If that is the case, we could not but rejoice. Many people would have to eat their hats with whatever grace they can muster: scientists, political leaders, international officials and everyone who believed them and relayed their fears — including me, if I am still around.
And now for the second hypothesis: humanity takes action. Benefiting from the political changes in the US, we see a major step change. Draconian measures are taken to reduce significantly fossil fuel consumption and carbon concentrations in the atmosphere. The rate of global warming slows, sea levels do not rise and no major drama linked to climate change takes place.
At this prospect, I imagine a debate between two scientists thirty years from now. One belongs to the majority consensus and supports the view that it was thanks to this step change that humanity escaped a global catastrophe which would have threatened its survival. The other belongs to the dissenting minority and continues stubbornly to insist that the dangers were grossly exaggerated and even simply an illusion. It is unlikely there would be agreement between them. Since the ‘patient’ is still alive, how can it be conclusively shown that he was in mortal danger? The two doctors by his bedside could debate indefinitely.
However, at one point in their discussion, the first scientist might say to the other: ‘Let’s forget our past quarrels and simply ask ourselves: isn’t our planet much healthier as a result of the course of treatment it followed? I will continue to maintain that it was in mortal danger and you will continue to doubt it, but weren’t our countries right to reduce their consumption of fossil fuels and their pollution from factories and power stations?’
And that is the basis of the wager I have formulated about climate change: if we proved incapable of altering our behaviour and the threat turned out to be real, we would have lost everything. If we did manage to change our behaviour radically, and the threat turned out to be illusory, we would not have lost anything at all. Because the measures which would allow us to face the threat of climate change are in reality, when you think about it, measures which are worth taking in any case — in order to reduce pollution and its harmful effects for public health; in order to reduce the threat of poverty and social upheavals which climate change could provoke; in order to avoid savage conflicts for control of oil fields, mining regions and water supplies; and in order for humanity to progress in greater serenity.
Consequently, it is not up to the majority of scientists to show that the threat is real. It is, rather, up to the dissenting minority to show irrefutably that the danger is completely illusory. The burden of proof is reversed, as a lawyer might put it. It is only if we are absolutely sure that this mortal danger does
Of course, such certainty is out of the question. The stakes are so high that no one — no researcher, industrialist, economist, political leader, intellectual, no sensible being — could take the responsibility for asserting, against the view of the vast majority of scientists, that risks linked to climate change do not exist and that we should simply ignore them.
In this field more than the others, all we can do is anxiously wonder which path humanity will take — that of a step change or that of business as usual.
The times we are living in give contradictory signs. On the one hand, our awareness is real and the weight of the US, which too long pushed down on the wrong side of the scales, should now tip the balance in the opposite direction. However, the hoped-for step change requires a level of solidarity and even a profound bond between nations which is not easy to achieve. And it demands sacrifices.
Are the countries of the North prepared to disrupt their way of life? Are emerging nations, especially China and India, ready to put at risk their economic take-off, the first chance they have had in centuries to escape underdevelopment? That supposes at the very least vast concerted global action, from which everyone gets something and no one feels hard done by.
I want to believe that such an effort is possible, but I cannot easily overcome my worries when I look at our world: a world characterised by profound asymmetry in international relations; a world in the grip of identity-based tribalism and supreme selfishness, in which moral credibility remains a rare commodity; a world in which great crises generally push nations, social groups, companies and individuals to protect their own interests fiercely rather than demonstrate solidarity or generosity.
