The question has been raised: Why spend time "debunking" S&N when they seem to be well-meaning folks struggling for a genuine solution to global warming, unlike, say, Bjorn Lomborg? Aside from the fact that they are adding great confusion and misinformation to a critical debate, the answer is simple -- they aren't well-meaning.
S&N spend far more time attacking the environmental community (and Al Gore and even Rachel Carson) than they do proposing a viable solution. Worse, they don't even attack the real environmental community -- they spend their time creating a strawman that is mostly a right-wing stereotype of environmentalists.
S&N's core argument is that environmentalists only preach doom and gloom and sacrifice, and that solving global warming ...
... will require a more optimistic narrative from the environmental community. Gore's An Inconvenient Truth, like Silent Spring, was considered powerful because it marshaled the facts into an effective (read: apocalyptic) story ...
In promoting the inconvenient truth that humans must limit their consumption and sacrifice their way of life to prevent the world from ending, environmentalists are not only promoting a solution that won't work, they've discouraged Americans from seeing the big solutions at all. For Americans to be future-oriented, generous, and expansive in their thinking, they must feel secure, wealthy, and strong.
Gore has never promoted such an inconvenient truth -- they should read his book or listen to his speeches -- and indeed I don't know any major environmentalist or environmental group that has promoted such a message. Just spend some time on the climate websites for NRDC, Environmental Defense, the Sierra Club, and Greenpeace. They all support (most of) the same big solutions S&N do, they just don't think you get those solutions the way S&N do (i.e., a massive government spending program).