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Shouldn't we wait until we are totally sure of what's going on before we do anything ?

september 2003

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Given what it would mean to live without oil, gas and coal, many political or business leaders (not to speak of each one of us...) are tempted to consider that we ought to be really sure of everything before we do anything. Alas, this bet, in the present case, is not very far from the russian roulette.

What determines a climate ?

A climate is defined mainly by the mean values of a number of variables, the main ones being temperature and pluviometry. These mean values are calculated over a 30 year period. Of course, the temporal pattern (all the rain falling in one episode or regularly falling all year round) is also of importance, as many other things.

This definition of the climate explains that when journalists ask their favourite question "are we looking at the consequences of climate change", what they like to do every time there is a hurricane, a flooding, a heat wave, etc, the answer given by the climatologists is invariably : it's to early to say so.

What else can they say : we will know in 2030 if the climate is different from that of 2000 ! But when we know, it's too late to reverse the evolution....

Indeed, when we are able to state, through non questionnable physical evidence, that the phenomenum has become explicit, we will then be very much engaged into a process irreversible for at least a couple centuries, if not more, because of the time of residence of the CO2 in the atmosphere.

Because of that considerable inertia of the process, not doing anything now and waiting for new breakthrough in science before acting should we deem it necessary, is already taking the bet that no major catastropha will happen in the future.

It is obviously a significant bet, and whose winners or losers will not necessarily be us (though a nasty surprise cannot be ruled out at any time) but our kids or grandkids, that can't give their opinion today, but will only be able to assist, powerless, if a major turmoil should it happen as a consequence of a present behaviour.

In addition, nobody can assume that some regions of the world will be spared. It is therefore a heavy responsibility towards our close descendants to choose not to tackle the problem today.

This issue, global and irreversible on a time scale of a couple of (human) generations, is a novation for our species. "Classical" pollution problems generally correspond to a situation mostly reversible, and, if not, geographically restricted. In other terms, the issue is either global but reversible over a couple of decades (hole in the ozone layer, whales, DDT in sea birds, etc) or irreversible but local (vanishing of the Aral sea, for example).

In the first case, the "solution" is to halt the degradation process before it's too late and patiently wait for the previous situation to restore itself, and in the second the "solution" is to accept that what is lost is lost but to act so that there are no further degradations.

Here, it is not possible, as we usually do, to think in terms of established problems, that we will manage once they exist, because they may well not be managable, and once we know it, it's too late ! (this points leads to all the debates on the "cost of climate change" being a little vain : climate change has an avoiding cost, but has no reparation cost, and no global cost). We can only behave in terms of risk management. But we are sometimes familiar with risk management : it's preciseley for that function that we have designed insurance companies.... Here the insurance premium is a quick decrease in the CO2 emissions (and that of other greenhouse gases), with the particularity that no gain or loss can be given a monetary counterpart that is not hypothetical.

It might have a cost (but some economists state that it would generate net jobs), but it would prevent us from a phenomena for which we don't know how huge it could be and that would last for a couple of centuries at least.


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