Chris Mooney of the Washington Post is one of our wisest journalists. A terrific tweet thread yesterday contrasts recent news and opinions from opposite ends of the pessimism spectrum. On the one hand, one of the most worrying scenarios in the recent IPCC work, known as RCP8.5, might be too pessimistic. The endless stream of ideological and scientific positioning around RCP8.5 can be boring but it’s also important, so this debate makes for fascinating purview. Against what might be labelled “good news” (it isn’t really, just one scenario that needs tweaking for future projections), scientists have dug over half a kilometer through one of Antarctica’s biggest glaciers and found that the glacier might be melting from underneath.
Quite how the ice up north and south responds to Earth’s increasing temperatures is of crucial importance to predicting the future. We know how worrying the concept of amplification is. For example, we can see that a degree of warming has burnt huge swathes of Australia to the ground, releasing even more carbon, amplifying the temperature hikes even more. If ice melting (be it on sea or on glaciers or on rock) amplifies warming or further melting, we could be in trouble.
In other words, as Mooney points out: “So in sum: The plausibility of RCP8.5 as an energy scenario for this century has been seriously challenged. But the potential severity of climate change really has not.”