"A leaked version of the newest science report from the U.N. Intergovernmental Panel on Climate Change warns of looming, potentially catastrophic tipping points for Arctic sea ice melt, tundra thaw, savannification of the Amazon rainforest, and other planetary environmental thresholds beyond which recovery may be impossible.
But what are tipping points, and how does one pinpoint what causes them, or when they will occur? When studying a vast region, like the Arctic, answering these questions becomes dauntingly difficult, as complex positive feedback loops (amplifying climate warming impacts) and negative feedback loops (retarding them) collide with each other.
In the Arctic, one working definition of a climatic tipping point is when nearly all sea ice disappears in summer, causing a Blue Ocean Event. But attempts to model when a Blue Ocean Event will occur have run up against chaotic and complex feedback loop interactions.
Among these are behaviors of ocean currents, winds, waves, clouds, snow cover, sea ice shape, permafrost melt, subarctic wildfires, aerosols and more, with many interactions still poorly understood. Some scientists say too much focus is going to tipping points, and research should be going to the “radical uncertainty” of escalating extreme local events."