Allocating a price to elements that condition our survival is, in fact, no more meaningful than knowing how much is worth our miserable existence. However a group of authors tried to perform that calculation a couple of years ago, and got to the following figures.
|TOTAL Marine ecosystems||21|
|Lakes and rivers||1,7|
|TOTAL Terrestrial ecosystems||12,3|
|TOTAL Marine + terrestrial ecosystems||33,3|
By services performed by the ecosystems
|Regulation of the composition of the atmosphere||1,3|
|Dampering of variations||1,8|
|Contribution to agriculture||3|
|Others (erosion control, soil formation)||3,6|
Annual value (world average) of the services performed by the ecosystems, in trillion dollars per year (10 to the 12th power dollars).
From Costanza et al. (Nature 1997).
Actually, as there would be no men in the absence of ecosystems, any figure suggested is necessarily arbitrary : how could we survive without water resources, or without a food production ? But let’s continue. Evocating trillion of dollars is meaningless for an individual : it is much more than what I will ever earn, and even much more than what any individual will ever earn. My objective is just to come to this simple application of elementary arithmetics : how much is it per person ?
We are presently 6 billion people on Earth. 33.000 billion dollars per year for “natural services” thus represents 5.000 dollars of services done for each individual, in rough figures. In other terms, we all have, with a way to calculate maybe no more inappropriate than any other one, an income coming from the “natural elements” which amounts to several thousand dollars per year. It might be interesting to compare this to the average GDP per person in the world, which is worth about the same (with this difference that we are unable to produce anything without natural elements !).
This can lead to the following conclusion : with a “Price Earning Ratio” (that is the number by which one must multiply the annual profit per share to get the price of the share) of 20 (these ratios vary between 5 and 100 at the stock market), the world natural patrimony is worth about 100.000 dollars per person.
Well the measures that aim at preventing climate change, that is dividing the greenhouse gases emissions by 2 in a couple decades, might cost, according to economists quoted by the IPCC, 1 to 2 points of world GDP at most from now to 2050, that is a couple hundred dollars at most by individual.
A basic – maybe too basic – economic reasoning can then be made : does it have a meaning to avoid spending a couple hundred dollars to preserve a patrimony which is worth a thousand times more ?