This week, we question the environmental impact of large-scale touring in classical music. At the same time, the art form has dealt aesthetically with the issue of climate change in works such as Giorgio Battistelli’s opera “CO₂.” But how effective can an opera based on “An Inconvenient Truth” be? This excerpt shows moments of textural beauty, but some of the libretto falls flat. A spoken passage goes, “If this is not my planet, whose is it? / If this is not my responsibility, whose is it?”