In his new book, “A Climate of Truth,” the climate analyst Mike Berners-Lee points out that efficiency hasn’t gotten us very far in reducing carbon emissions. The more efficient we get, the more energy we use—and so far that’s kept demand for fossil fuels high — negative gains in energy derived from renewables. Berners-Lee says there is a singular shift that would go far toward solving our efficiency conundrum and every other climate bind we’re in: It’s holding corporate and political leaders accountable to truth.