密歇根新闻广播 为什么某些国家的自然灾害导致美国移民增加（在线收听）

While the politicians argue about it, the U.S. Department of Defense is trying to prepare for the effects of climate change. The Pentagon sees it as a national security issue. One of the predictions is that there will be massive migration because of extreme weather events leading to flooding or drought or other disasters.

There's evidence of that sort of trend happening in the aftermath of hurricanes.

Dean Yang, professor of economics and public policy at the University of Michigan, co-authored an article for The Conversation titled "Hurricanes Drive Immigration to the U.S." He joined Stateside today to explain his research.

"Immigration rises quite remarkably after countries are hit by hurricanes overseas," he said, "but that effect really is isolated in countries that have large migrant populations in the U.S. already, who can help ease the way for new migrants to come in in response to hurricanes."

While there are several ways former migrants to the U.S. can help family members follow in their footsteps, Yang said there's one way that sticks out in the data.

He said prior migrants, current U.S. citizens and permanent residents, help by applying for green cards for their relatives. That leads to a "big increase" in green card issuances by the U.S. government to people from the country who suffered the natural disaster.

Yang said his research shows how helpful family reunification policies can be.

"In this new political environment we're in, anything can happen and so it's important to understand that these policies really are important in helping people overseas who might have relatives already in the U.S. cope with disaster by being able to immigrate to the U.S," he said.

Listen above for the full conversation.