When the Center for Climate and Security released its threat assessment last week in Washington D.C., its director asked the experts what keeps them up at night. What emerged was a list of nightmare scenarios most striking because many are already happening:

1 Sudden Sea Level Rise

If you look at the potential sort of black-swan incidents or the tipping points of a Greenland ice sheet collapsing or parts of Antarctica breaking off,” said former Undersecretary of Defense Sherri Goodman, “then you have global sea levels rising much more rapidly—within a matter of a couple of decades.”

In many parts of the planet, including the United States, major cities and coastal areas then become uninhabitable because of coastal erosion and storm surge, Goodman said.

2 Increase in Unlivable Space (Non-ecumene)

We already have what I would characterize as unlivable spaces in this world,” said John Conger, a former deputy secretary of defense who serves as director of the Center for Climate and Security. “But what the science predicts is that we’re going to have unlivable spaces where people currently live.”

As people run out of food and water or experience lethal temperatures, they will have to move, Conger said, “and that will create a ripple effect throughout the world.”

3 Fragile And Failed States

When you look at the effects of climate change and climate change-linked effects on labor, on agriculture, on fisheries, on insurance, on public health, you start to paint a picture of real serious impacts on not just the vulnerable—the vulnerable and the unlucky. The people affected in that Venn diagram grows with time,” said Rod Schoonover, a former director of environment and natural resources for the National Intelligence Council who now teaches in Georgetown University’s School of Foreign Service.

We are already seeing pockets of instability in Africa and the Middle East,” he said.

Climate effects and climate-linked effects will likely add to the list of fragile and failed states,” he said. “But also the countries that are already struggling, climate has an effect on keeping them from recovering.”

The U.S. has invested billions of dollars in countries like Iraq and Afghanistan where climate change will make recovery more difficult, Schoonover said. The U.S. and its values do best in a world that’s stable, “and so we’re really looking at a bleak future.”

4 Collapse Of Democracy And Relations

Climate change will lead to migration, and recipient countries often respond to migration with ethnic and nationalist movements, with reduced cooperation between countries.

It’s always very tempting for countries to respond to very scary shocks with authoritarian responses,” said Kate Guy, principal investigator with the Center for Climate and Security at the University of Oxford.

I worry that the Democratic project is at risk,” Guy said. “I worry that the international project, which our country has really led, is at risk as well.”

5 Nuclear Accidents

Goodman “absolutely believes nuclear power has to be part of the clean energy future,” she said, but she nonetheless worries about nuclear technology in the hands of countries that have not been reliable actors.

We know that Russia doesn’t have the best nuclear safety record, from Chernobyl to the Kursk submarine,” she said. “I am worried about over-militarization by those who don’t have a record of good nuclear safety operations.”

Russia is rushing into the thawing Arctic, said Goodman, who chairs the Council on Strategic Risks, which did a tabletop simulation of a Russian nuclear icebreaker colliding with a Chinese LNG freighter in the Bering Strait, where Russia and the U.S. are only 30 miles apart. The United States, it found, is unprepared for such an event.

6 Pandemics And Other Wild Cards

With global order already under stress, the sudden appearance of a wild card like the coronavirus creates more disorder, said Ambassador Richard Kauzlarich, the co-director of the Center for Energy Science and Policy at George Mason University.

What scares me—because I’ve read the newspapers today about the pandemic—is the intersection of these climate-caused crises, including the public health dimension, with a unpredictable wild card, you know a global issue that makes these things even worse, and you end up with a complex system of responses that we’re not prepared for.”

These nightmare scenarios align with the world’s current trajectory—a 4º C increase in average global surface temperature. But that trajectory can still be altered, said Conger, and many of these effects can still be avoided.

Will we avoid the 2º scenario? Maybe not,” Conger said. “Do we have the capacity to avoid the 4º scenario? I think so.”

Jeff McMahon

Published by Forbes, 2 March 2020