The estimated "global cost" is $ 45 TRILLION. Of course we all know that that figure is probably the very LOW END cost. We also know whom the world [and the demonrats] expect to pickup the lions share of that cost - the U.S.
The whole thing is a waste since neither China nor India are likely to join the effort. In fact the prime minister of India flattly stated that his country would never agree to something which would impact his country's growth.