Hans-Joachim (“John”) Schellnhuber

The conventional wisdom is that Pope Francis will stay away from the scientific details in his forthcoming encyclical on climate change. George Weigel’s Roman contacts, for example, “suggest that ‘he won’t get into the science.’”

The conventional wisdom is wrong.

How do I know this? No, I haven’t gotten a sneak peek at the document, which will be unveiled at an 11 a.m. press conference in Rome next Thursday. I know this because yesterday the Vatican announced that one of the three panelists at the unveiling will be Europe’s leading climate scientist.

He’s John Schellnhuber, founding director of the Postdam Institute for Climate Change and the person responsible for proposing that  global mean temperatures be stabilized at two degrees Celsius above the pre-industrial level — currently the target of international climate negotiations. He will not be in Rome as scientific window dressing.

Sitting alongside Cardinal Peter Turkson, the Vatican’s point man on climate, and Metropolitan John (Zizioulas) of Pergamon, the leading Greek Orthodox theologian, he will, I predict, explain why the two-degree goal, if achieved, will itself require major efforts to remove carbon from the atmosphere. More importantly, he will stress the need for very fast emissions reductions in accordance with the science, pointing out that if no action is taken, billions of people will die.

A major object of the exercise, for Schellnhuber as well as the pope, will be to ensure that the U.N.’s upcoming climate conference in Paris does what needs to be done. “It will not be a piece of cake,” he told Reuters this month. “It would be perhaps comparable to what the United States did in the Second World War — they changed their economy to producing tanks rather than automobiles.” 

Naturally there will be all kinds of pushback, much of it claiming the political impossibility of achieving the necessary reduction in carbon emissions.

“It’s just not feasible,” Oliver Geden, of the German Institute for International and Security Affairs, was quoted by the Guardian as saying. “Two degrees is a focal point for the climate debate but it doesn’t seem to be a focal point for political action.” Five years ago, Schellnhuber briefed Obama administration officials and was informed that his findings were “not grounded in political reality” and that “the Senate will never agree to this.”

Schellnhuber’s response? “Political reality must be grounded in physical reality or it’s completely useless.” How much do you want to bet that the encyclical won’t be grounded in physical reality?