Planet Earth (NASA) In late 1992, 1,700 scientists from around the world issued a dire “ warning to humanity .” They said humans had pushed Earth’s ecosystems to their breaking point and were well on the way to ruining the planet. The letter listed environmental impacts like they were biblical plagues — stratospheric ozone depletion, air and water pollution, the collapse of fisheries and loss of soil productivity, deforestation, species loss and catastrophic global climate change caused by the burning of fossil fuels. “If not checked,” wrote the scientists, led by particle physicist and Union of Concerned Scientists co-founder Henry Kendall , “many of our current practices put at serious risk the future that we wish for human society and the plant and animal kingdoms, and may so alter the living world that it will be unable to sustain life in the manner that we know.” But things were […]