John Williams has been making wine in California’s Napa Valley for nearly 30 years, and he farms so ecologically that his peers call him Mr. Green. But if you ask him how climate change will affect Napa’s world famous wines, he gets irritated, almost insulted. “You know, I’ve been getting that question a lot recently, and I feel we need to keep this issue in perspective,” he told me. “When I hear about global warming in the news, I hear that it’s going to melt the Arctic, inundate coastal cities, displace millions and millions of people, spread tropical diseases and bring lots of other horrible effects. Then I get calls from wine writers and all they want to know is, ‘How is the character of cabernet sauvignon going to change under global warming?’ I worry about global warming, but I worry about it at the humanity scale, not the vineyard scale.”