New Orleans might be the city least prepared for future climate and environmental changes — not just in the U.S., but globally.

That’s according to a new report from First Street, a group that researches risks associated with climate change, which compared economic resilience measures with climate-related threats in 426 cities across the globe. Of those cities, New Orleans ranked last, thanks to a dwindling population, the high costs of insurance, and risks from floods, heat and hurricanes. 

First Street aims to help businesses and policymakers make decisions that factor in future climate risks.

“How do we understand the physical impacts of climate change … to make these resilience decisions, adaptation decisions, and ultimately investment decisions?” said First Street CEO Matthew Eby. “That’s really our goal here.” 

Researchers looked at what First Street terms the “resilience spread” in cities around the world, measured as the difference between an area’s economic productivity and its exposure to climate change–driven threats. The better the local economy, measured alongside metrics like population trends and the quality of its housing stock, the better a city is expected to be able to fare in the face of worsening environmental threats. 

By that metric, a city like Johannesburg, South Africa, is expected to fare well in a future shaped by climate change, thanks to what researchers identified as a large and growing working-age population, strong consumer spending, and a diversified economy that spans services, industry, and mining. While the city is expected to face moderate risks of flooding, wildfire and drought, its strong economic outlook increases the likelihood it will be able to handle future climate adversity. 

The outlook for New Orleans is not so good. 

Though the city has a strategic port, located at the mouth of the Mississippi River, and has a cultural economy that is singular in the Gulf South, the researchers note that it faces already-extreme risks associated with flooding and hurricanes, which are forecast to intensify as the climate heats. The city’s population is declining, while insurance grows increasingly unaffordable as insurers weigh abandoning the market. 

‘Capacity for resilience’

Amsterdam, the report finds, faces similar climate change risks. But First Street found that Amsterdam has a more robust economy and a long history of managing flood risk, which helps offset its level of climate change–driven flood risk. 

New Orleans, meanwhile, depends on the U.S. Army Corps of Engineers and the federal government to adapt to its risks. 

“Amsterdam’s climate risk is almost fully mediated by its market capacity for resilience,” said Jeremy Porter, First Street’s head of climate implications. “New Orleans still has a huge spread associated with its climate risk and market impact.” 

Globally, the report finds that climate risk is projected to wipe out more than $2.5 trillion in global productivity, or about 2% of today’s gross domestic product. Many of the cities that appear resilient to climate change today may look more like New Orleans does now, as climate change intensifies over the course of the 21st century. 

First Street relied on proprietary data that the organization sells to private companies to help inform investment and policy decisions. That data has previously shown nearly twice as many properties at risk of flooding as indicated by Federal Emergency Management Agency maps, which research has found often underestimate flood risk. 

But some homeowners say the data about their properties is inaccurate, and the American Flood Coalition, a Washington, D.C.–based bipartisan organization on flood policy, cautioned that it should not be used for quantifying risk, regulatory decision-making, or as a replacement for FEMA flood maps. 

“Yes, New Orleans is at risk,” said Joel Scata, a senior attorney for the Natural Resources Defense Council who focuses on flood policy. “But I don’t necessarily agree that it’s at risk more than New York or Miami, which both face hurricane and flood risks.”

Still, the report underscores the importance of increasing investments in measures like flood protection, which will help local communities adapt to climate change, Scata said. 

“Absent action, communities in these high-risk zones are going to continue to experience economic and social upheaval, regardless of the metrics that you use,” he said. “We’re not going to see climate change disappear. We’re only going to be able to limit its impact. Adaptation is an absolute must at this point.”