David M. Lodge is Francis J. DiSalvo director of the Atkinson Center for a Sustainable Future at Cornell University.

Disasters often bring out the best in Americans — cooperation, kindness and dogged perseverance supersede political and provincial ideologies. One need only look back to the warm greeting between President Barack Obama, a Democrat, and Republican New Jersey Gov. Chris Christie two days after Superstorm Sandy devastated the Garden State in 2012.

But these disasters also serve to separate Americans, widening the gap between the “haves” and the “have-nots” and increasing wealth disparities. Fortunately, environmental policy changes can help close that gap.

As Hurricane Michael departs the ravaged Southeast, I have just returned from a trip to Morehead City, N.C., to clean up after last month’s Hurricane Florence. Five years ago, in preparation for our eventual retirement, my wife and I bought a modest mid-century house there. As an environmental scientist, I knew something like Florence would come sooner rather than later, as tropical storms have become more powerful with climate change. So we purchased our retirement property atop a 25-foot-high bluff, one of the highest points in the area. Our house was undamaged despite many large limbs and treetops littering the yard, and we have insurance if we ever need it.

But for many others, Hurricane Florence will be remembered as a permanently life-altering event. Many North Carolina politicians deny climate change, and the state legislature prohibits local planning boards from considering future climate-change induced sea-level rise in making coastal development decisions. Driving through the flood-devastated regions of the state vividly illustrated such folly: So many people living closer to sea level, in river floodplains or merely in low-lying areas are returning to their communities with no homes or employment.

While beautiful seaside lots in the state command top dollar, homes located in riverine flood zones and other low-lying areas often do not. To compound the misery of water damage, flooding often delivers a toxic brew. The effects of flooded lagoons of pig waste and coal ash on human health, environmental health and estuarine fisheries will be felt for months or years to come.

Health effects aside, even a temporary period with no home and no job will put the trajectory of many lives into a spiral of declining economic and social well-being. With no flood insurance, there are no means to rent, buy or build again. No home. No employment. No savings. And a porous FEMA safety net. This is the human face of policy-induced suffering.

Research has already connected wealth inequality and the rising costs of natural disasters. We’ve seen how Houston’s Hurricane Harvey and New Orleans’s Hurricane Katrina struck the economically disadvantaged harder than anyone else. Now I’ve seen those effects up close.

The children and grandchildren of North Carolina’s newly homeless are more likely to struggle financially and have less hope of achieving the American dream than they had before the storm. Just ask all the people still living in temporary housing in Puerto Rico more than a year after Hurricane Maria.

My wife and I had the chance to carefully consider sea-level rise and other aspects of climate change while selecting our property. But many of our neighbors did not have that luxury. I’m more aware now than ever before that I am a “have.” And I can put faces on those who bore the brunt of the consequences of policy divorced from science.

Without changes in federal and state policies, the economic divide will grow even faster as climate-induced flooding ravages our country. A host of federal and state environmental and development policies exacerbates this disparity, including Environmental Protection Agency policies that allow increased greenhouse-gas emissions and state regulations such as those in North Carolina that allow development in locations increasingly prone to flooding.

Consider, for example, the Federal Emergency Management Agency’s National Flood Insurance Program, which faces three urgent policy problems: First, maps of flood risk are hopelessly outdated. Three times as many people than previously thought are at risk of serious flooding in the United States, especially in inland areas. Second, flood insurance rates have not kept up with increased risks, resulting in a $20 billion debt load despite congressional bailouts. Finally, even where flood insurance is required, that requirement is often not enforced, resulting in more destitute people when disaster strikes and further taxpayer subsidies to those living where it is increasingly unreasonable to live.

When the flood insurance program’s authorization expires in November, Congress needs to update it with climate change realities in mind. Let’s hope political amity in the aftermath of this season’s hurricanes will last long enough for lawmakers to pass meaningful reforms. By allowing current science to inform policy, legislators would also be protecting the most vulnerable in our country and reducing the growth of the wealth gap.