Value of Earth
In green economics, value of Earth is the ultimate in ecosystem valuation, and important to value of life calculations. It begins with the simple problem that if the Earth ceases to support life, and human life does not continue elsewhere, all economic activity will also cease.
There are several ways to estimate the value of Earth:
As one might expect, these all produce quite high values for the entire Earth, usually at least in the hundreds of quadrillions of US dollars. This seems appropriate. However, even with this sum in hand, it seems unlikely that even experienced reconstruction subcontractors could complete the task of replacing Earth, certainly not without using Earth itself as a base. Rent for use of Earth and its orbit might then also have to be included, and it would be hard to price this without calculating the price of the Earth, again.
One way around this is to simply declare the Earth priceless or to be exactly and only as valuable as all financial capital in circulation. This may be equivalent to declaring it worthless, however, as neoclassical economics deals very poorly with assets that are too valuable to trade actively in markets.
Returning to the calculation in terms of the replacement cost of Earth's bio-systems: (Note: All the numbers in this section use the short scale, not the long scale.)
In Biosphere 2, over $240 million was spent on developing the infrastructure to support eight people for two years. The project failed and fresh air had to be pumped in to save the lives of the participants. So Earth is worth at least:
This represents the minimum value of the Earth using today's technology. Because the project failed, the true value must be higher than this amount. However, economies of scale in biosphere production would obviously reduce this number significantly. Mass production of one billion biosphere units would reduce the per-unit cost by several orders of magnitude.
To put this into perspective, assuming the total value of the gross world product is $30 trillion, that sum divided into $1.95 × 1017 = 6500 times the world's current gross product.
From this we can estimate the cost of cutting a tree or taking a single fish from the ocean if there is evidence that that yielded resource unit may not be replaced. The probability that the resource will be replaced reduces the cost, so a 50% chance that it will be replaced implies that the cost should be cut in half, since two of them can be taken, on average, before one is not replaced.
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