Book excerpt: In twenty short books, Penguin brings you the classics of the environmental movement. In the galvanising speeches and essays brought together in This Can't Be Happening, George Monbiot calls on humanity to stop averting its gaze from the destruction of the living planet, and wake up to the greatest predicament we have ever faced. Over the past 75 years, a new canon has emerged. As life on Earth has become irrevocably altered by humans, visionary thinkers around the world have raised their voices to defend the planet, and affirm our place at the heart of its restoration. Their words have endured through the decades, becoming the classics of a movement. Together, these books show the richness of environmental thought, and point the way to a fairer, saner, greener world.