The nine boundaries humanity must respect to keep the planet habitable Newsroom 2 hrs ago Mongabay Climate change is just one of nine critical planetary boundaries, and we’re living beyond four of them, writes Claire Asher Advanced human societies emerged during an unprecedented period of stability on Earth. During the 12,000 years before the Industrial Revolution, our planet’s surface temperature varied by less than 1° Celsius above or below the average for that entire period. As a result, life — both human and wild — thrived. But over the past two centuries, humanity has dramatically increased greenhouse gas concentrations in the atmosphere, pushing us outside this “safe” climate zone; outside the conditions for which civilisation has been designed.