Al Gore’s latest global warming movie will open in U.S. theaters on Friday. “An Inconvenient Sequel: Truth to Power” arrives eleven years after his award-winning “An Inconvenient Truth.” In the interim, conservatives like talk-radio host Rush Limbaugh haven’t let Mr. Gore forget his most dire and least accurate weather predictions. But the Gore analysis on another issue is being rejected by even some of his committed climate allies.

The good news for all of us is that Mr. Gore appears to have overstated the threat of eco-apocalypse,...