The National Water System would produce infrastructure and operate services to enable universal irrigation. This would enable conversion of vast underused land area into productive farms. It would also end the effects of drought and flood. The Miastrada Dragon (see idea) is being developed to function in the context of such expanded agriculture.
A part of the land would be directed to establishing standing forests to most directly mitigate CO2 in the atmosphere, where a ton of standing wood mass, including root structure, would roughly balance a ton of coal burned in power plants, or other fuel equivalent. A general agregate of wood mass that is permanently in being, as with collections of orchards, would also balance fossil fuel burning.
The general benefit would be more powerful, that being a return to positive production of our agro-industrial country. This would enable continuation of our developed world, wherein people have inclination to think about such problems as global warming.