Unless you work deep in the climate policy mines or are one of the few laypeople out there who read every page of the IPCC’s fifth assessment report back in 2013, you’ve probably never heard of the RCP-8.5 Pathway. But you’ve almost certainly interacted with its conclusions: they have become the widely accepted baseline for climate modelers and informed the more apocalyptic predictions about sea level rise, glacial melt and other potential outcomes of a rapidly warming world. 

Now, after years of internal debate within certain corners of the climate community, it’s officially being retired. “Because of the growth in renewable energy,” the New York Times’s Eric Niiler writes, “the worst-case outlook is being revised downward. In a paper published in April, a committee of top climate experts from around the world said that now the worst-case scenario would be that the planet could heat up by an average of 3.5 degrees Celsius, or just over 6 degrees Fahrenheit.”

This is still, of course, catastrophically dangerous. Even the likelier range of warming identified by scientists of 2.5 to 3 degrees Celsius would be life-threatening for millions of people around the world, while Bloomberg New Energy Finance’s latest “economic transition scenario” — that is, the base case that makes no assumptions about new climate policies and instead relies purely on economic inputs — puts projected warming at 2.4 degrees Celsius........

© National Observer