Solomon Hsiang, the Chancellor’s Professor of Public Policy at the University of California, Berkeley, and a co-director of the Climate Impact Lab, agreed that trade might simultaneously make the world more resilient to these disasters and more vulnerable. In some situations, trade can help soften the effects of climate change — for example, allowing communities to import food when local crops fail because of a drought, he said. “That’s on the good side of the ledger,” Mr. Hsiang said. “But the bad side is, as everyone really acutely understands, we are so interconnected from our supply chains that events on one side of the world can dramatically impact people’s well-being elsewhere.”