‘HUMANITY’S FINAL EXAM’ – DISTINGUISHING BETWEEN MOMENTARY AND MILLENIAL RISKS

By

Andrew C. Revkin

Raymond Pierrehumbert, a longtime climate scientist now at Oxford, stopped by The New York Times earlier this month for a long fruitful chat on climate change science and solutions and the hurdles — mostly internal and social (including political) — that impede progress. He concluded by saying this juncture in our history — decisions (or indecision) in our lifetimes — constitutes “humanity’s final exam”:

The biggest challenge is grappling with divergent scales. Compare the year-to-year scale at which humans make policy decisions, reflected in our political frameworks, to the multi-millennial consequences of today’s energy choices, as delineated in “Consequences of twenty-first-century policy for multi-millennial climate and sea-level change,” the important recent commentary in Nature Climate Change by a host of top climate scientists, including Pierrehumbert. (I explore this in the context of the Paris climate agreement in a short set of slides here.)

In this context, I hope you’ll read Nick Kristof’s new column, “Terrorists, Bathtubs and Snakes,” which is about human misperception of relative risk. Its theme is distilled in this line: “Brussels survived this week’s terror attacks, but it may not survive climate change.”

There’s a section in Kristof’s piece related to the newly published paper by James Hansen and others proposing that the world is poised for rapid sea-level rise and superstorms. (Read a fine analysis by Robinson Meyer in The Atlantic to get caught up since my coverage of its review last year.) Here’s Kristof comparing our reactions to terrorism and climate change: 

On the same day as the attacks, a paper by James E. Hansen and other climate experts was released arguing that carbon emissions are transforming our world far more quickly than expected, in ways that may inundate coastal cities and cause storms more horrendous than any in modern history. The response? A yawn.

Hansen is an eminent former NASA scientist, but he’s also an outlier in his timing forecasts, and I’m not qualified to judge whether he’s correct. Yet whatever the disagreement about the timeline, there is scientific consensus that emissions on our watch are transforming our globe for 10,000 years to come. As an important analysis in Nature Climate Change put it, “The next few decades offer a brief window of opportunity to minimize large-scale and potentially catastrophicclimate change that will extend longer than the entire history of human civilization thus far.”

To put it another way, this year’s election choices may shape coastlines 10,000 years from now. Donald Trump and Ted Cruz have both mocked the idea of human-caused climate change, with Trump suggesting that it is a hoax invented by China to harm the American economy (he now says that last point was a joke).

The upshot is that Brussels survived this week’s terrorist attacks, but it may not survive climate change (much of the city is less than 100 feet above sea level).

Doesn’t it seem prudent to invest in efforts to avert not only shoe bombers but also the drowning of the world’s low-lying countries?

“We have a political system that engages quickly and powerfully in response to terrorism and security risks,” notes Daniel Esty, an environment expert at Yale Law School, “but doesn’t seem capable of galvanizing action on climate change and other risks that are less visible and spread over time and space.”

The reason seems to be — how do I put this politely? — that we evolved in ways that leave us irrational.

When we spot a harmless garter snake, our brains light up with activity as we process the “threat.” That’s because as primate brains evolvedover tens of millions of years, poisonous snakes were a threat that we are highly adapted to address, with special brain cells that are extremely sensitive to snake images.

Unfortunately, our brains are not well adapted to most of the biggest threats we actually face in the 21st century. Warn us that climate change is destroying our planet, and only a small part of our prefrontal cortex (which worries about the future) will glimmer; then we’ll go back to worrying about snakes or their modern equivalent — terrorists.