Demographers predict that the human global population will reach 9 billion by 2050, and indeed, we are now just about to pass 7 billion. But what could be a boom is likely to go bust, Robert Engelman warns at Yale 360. He is president of the WorldWatch Institute, which monitors the life support systems on Earth, and the human impacts upon them. Although demographers project a booming population that will level off at 12 billion with an increased life expectancy, the environmental trends do not support this projection, he notes. The world is heading toward a warmer and harsher climate, less dependable water and energy supplies, more acidic oceans, less intact ecosystems with fewer species, and less naturally productive soils. Population growth itself is undermining the basis for its own continuation. Indeed, since 1900, countries home to nearly half the world’s people now have chronic water stress or scarcity based on falling per-capita supply of renewable fresh water. The doubling of humanity has cut the amount of cropland per person in half. Far more scary than Halloween goblins, folks.