Chapter five of Common Wealth is called "Securing Our Water Needs," an important topic but one neglected by most economists. One lesson is that climate change will put a big stress on water supplies. So far, so good, but the recommendations start with greater international cooperation:
A first step, at least, would be to focus on the hardest-hit lands, specifically the world’s drylands. Fortunately, these are covered by the UN Convention to Combat Desertification, which has 191 member governments as signatories. Unfortunately, the treaty as it now stands is little known and has little clout and financial backing. Rather than reinvent the treaty, however, it would be better to reinvigorate it.
I would say it needs invigoration, not reinvigoration. It is no accident that the Convention has little clout and little financial backing. Many such Conventions are toothless objects, designed to appeal to a least common denominator within the process of the Convention itself (recall, it has 191 signatories). No one is opposed to "international cooperation" but it is no accident that truly international bodies have to either find a way to make profit (e.g., the World Bank lends to China) or they are usually very strapped for funds. That’s just not where the political rents are and that isn’t going to change.
Since Sachs calls this a "first step," his position is in some sense invulnerable. Whatever you really think should be done can be called the next step. Sachs writes, however, that the next step is more finance if I understand him correctly he wants to increase funding by more than a factor of 100). I would prefer finance from national governments, or even from the states or provinces, than finance at the level of international organizations. Most of the 191 signatories just aren’t that good at R&D, funds accountability, or even technology adoption.
I might add that national governments are the ones that subsidize the price of water to ridiculously low levels, most of all for agriculture. My first step is to remove all these water subsidies, allow water prices to rise, institute more water trading, and then see which innovations the private sector decides to finance (hmm…those are my first four steps). One role for government would be to ensure that patent law does not hinder international transfer of worthwhile innovations, a point which Sachs makes in other contexts. That sounds less glamorous than a big international plan, but I think it has a better chance of succeeding.