Art exhibitions that try to reckon with humanity’s ever-deepening impact on the environment tend to take one of two approaches: they present either a moralizing suite of ecological horrors or a feel-good tour of a possible greener future. “Sentient Earth,” at the nonprofit exhibition space Amant in East Williamsburg, Brooklyn, does neither. Instead the show offers a bracing survey of the many meanings that humans find in what they take from their environment. These are evident in the Surrealist jungle scenes of Hélio Melo, a self-taught artist and rubber tapper who painted with pigments he made from Amazonian plants, as well as in Ignacio Gatica’s LED -screen sunsets, with angular horizons that double as real-time graphs of changing prices for commodities such as copper and oil. The curators tease the hypothesis that the earth is a conscious thing full of feedback mechanisms.…