Scientific American: As Secretary of State under President Ronald Reagan, George Shultz helped negotiate the most successful global environmental treaty to date: the Montreal Protocol, which phased out the use of chlorofluorocarbons and other ozone-depleting chemicals. Those chemicals also act as potent greenhouse gases, so the agreement also makes him the negotiator of one of the most effective global climate treaties ever, despite being part of an administration that famously removed solar technology from the White...