d auctioning extra carbon dioxide credits for a global carbon dioxide market, since the shade allows us to be far less drastic in reducing growth of carbon dioxide emissions. If instead of a market we go with carbon taxes the project could be funded from those. $10 billion per year is much lower than even the most optimistic estimates (at 1% of world GDP about $500 billion per year) of the costs of reducing carbon dioxide emissions. Furthermore, there are a variety of other markets for large-scale industry that can be exploited once the basic ice mining infrastructure is developed: space tourism and making manned missions and other transportation around the solar system vastly less expensive, for starters, as well as providing propellant, tankage, and industrial raw materials in earth orbits. As I stated in 1994:
If the output of the icemaking equipment is high, even 10% of the original mass [returned to earth orbit by rockets using water propellant extracted from the comet ice] can be orders of magnitude cheaper than launching stuff from Earth. This allows bootstrapping: the cheap ice can be used to propel more equipment out to the comets, which can return more ice to Earth orbit, etc. Today the cost of propellant in Clarke [geosynchronous] orbit, the most important commercial orbit, is fifty thousand dollars per kilogram. The first native ice mission might reduce this to a hundred dollars, and to a few cents after two or three bootstrapping cycles.The savings for transporting materials to the earth-sun L1 point, instead of launching them from earth, are even larger.