CORVALLIS, Ore. – Scientists say multiple Earth system components appear closer to destabilization than previously believed, putting the planet at increased risk of a “hothouse” trajectory driven by feedback loops that can amplify the consequences of global warming. “The risk of a hothouse Earth trajectory” is an analysis by an international collaboration led by Oregon State University’s William Ripple that synthesizes scientific findings on climate feedback loops and 16 tipping elements – Earth subsystems that may undergo loss of stability if critical temperature thresholds are passed. Those sharp changes could likely result in a cascade of subsystem interactions that would steer the planet toward a path to extreme warming and sea level rise – conditions that could be difficult to reverse on human timescales, even with deep emissions cuts. …Tipping may already be happening with the Greenland and West Antarctic ice sheets, the scientists say, and boreal permafrost, mountain glaciers and the Amazon rainforest appear on the verge of tipping.