Climate's Battle of the Tipping Points

(I published this column recently on The Climate Capitalist. Please subscribe there for future free columns. Illustration is by Michael Simons)

Earth’s alarm bells are ringing. But it’s not just serial hurricanes, droughts, and floods sounding the alarm. Scientists tell us even more wholesale climatic transformations are possible, if Earth’s natural systems pass certain “tipping points.”

Author Malcolm Gladwell popularized the term in his 2007 mega-bestseller The Tipping Point: How Little Things Can Make a Big Difference. But at a New York Times panel during New York Climate Week, “How Close is Climate to a Tipping Point?”, ocean scientist Stefan Rahmstorf of Potsdam University explained its particular meaning in ecosystem science: “Self-amplifying feedbacks take over. And then it changes without further pushing by itself, unstoppable.”

Rahmstorf is most worried about the so-called Atlantic Meridional Overturning Circulation, or AMOC. This vast set of ocean currents begin near South Africa and carry warm salty water up to the North Atlantic. (The Gulf Stream, which goes from Florida up the U.S. East Coast, is part of it.) The AMOC “works like a central heating system,” he said. Were it to stop, which Ramstorf believes is more than 50% likely this century, Europe would get very cold very fast. (That’s right: overall global warming could lead some regions to become much colder.) Other cascading and negative results would include a rise of almost two feet in North Atlantic sea levels, major shifts in rainfall, and a radical decline in how much CO2 the ocean absorbs, further compounding climate change.

Scientists also worry about the collapse of the Greenland ice sheet and catastrophic releases of methane, a powerful greenhouse gas, as permafrost melts in Northern regions. (I wrote about this last one in a recent Climate Capitalist piece.) Either of these would have disastrous negative impacts on human life.

But for all that, the big picture is not completely grim. Tipping points are also emerging in the development of climate technologies—very positive ones. The emergence of newly inexpensive and powerful capabilities will help significantly reduce greenhouse gas emissions.

So it really is a battle, or a grim race of tipping points: if technology phase shifts happen faster than climatic ones, the world could make great progress fending off global warming.

In the last decade the cost of solar photovoltaic technology has dropped 76%, reports the Rocky Mountain Institute (RMI), and keeps falling.... (to keep reading, go here)