By Reynard Loki, AlterNet’s environment, food and animal rights editor. Follow him on Twitter @reynardloki. Email him at reynard@alternet.org. Originally published at Alternet

People love living near the coast. Only two of the world’s top 10 biggest cities—Mexico City and Sáo Paulo—are not coastal. The rest— Tokyo, Mumbai, New York, Shanghai, Lagos, Los Angeles, Calcutta and Buenos Aires—are. Around half of the world’s 7.5 billion people live within 60 miles of a coastline, with about 10 percent of the population living in coastal areas that are less than 10 meters (32 feet) above sea level.

Coastal migration has been steadily trending upward. In the U.S. alone, coastal county populations increased by 39 percent between 1970 to 2010. As the population skyrockets—from 7.5 billion today to 9.8 billion by 2050, and 11.2 billion by 2100, according to a recent United Nations report—the question for sustainability and development experts is, will the world’s coasts bear the burden of all this humanity? But with the rise of both sea levels and extreme weather, perhaps a better question is, will all this humanity bear the burden of living along the world’s coasts?

Pedestrians wade through water during a heavy rain in Mumbai, India, this summer. Recent floods in South Asia have been the heaviest in a decade. (image: bodom/Shutterstock)

Growing Appeal: Landlocked Life

As the “500-year” hurricanes Harvey and Irma (and 2011’s Irene) powerfully and tragically demonstrated, living near a coastline is an increasingly dangerous proposition. But for some coastal regions, rising seas and hurricanes aren’t the only cause for alarm: the coastal lands in Virginia, North Carolina and South Carolina are sinking by up to 3mm a year, according to a new study led by researchers at the University of Florida. Could these multiple factors reverse humans’ seaward migration?

Some research suggests that may be the case. A recent University of Georgia study found that rising sea levels could drive U.S. coastal residents far inland, even to landlocked states like Arizona and Wyoming, which could see significant population surges from coastal migration by 2100. Many of these places are not equipped to deal with sudden population increases. That means sea level rise isn’t just a problem for coastal regions.

“We typically think about sea-level rise as being a coastal challenge or a coastal issue,” said Mathew Hauer, author of the study and head of the Applied Demography program at the University of Georgia. “But if people have to move, they go somewhere.”

Nicknamed the Mile-High City, Denver is the highest major city in the United States. It ranks 11th on the list of American cities with the greatest addition of residents, helping to make Colorado the second fastest growing state in the nation. (image: Hogs555/Wikipedia)

“We’re going to have more people on less land and sooner than we think,” said Charles Geisler, professor emeritus of development sociology at Cornell University. “The future rise in global mean sea level probably won’t be gradual. Yet few policy makers are taking stock of the significant barriers to entry that coastal climate refugees, like other refugees, will encounter when they migrate to higher ground.”

Geisler is the lead author of a study published in the July issue of the journal Land Use Policy examining responses to climate change by land use planners in Florida and China. He and the study’s co-author, Ben Currens, an earth and environmental scientist from the University of Kentucky, make the case for “proactive adaptation strategies extending landward from on global coastlines.” By 2060, about 1.4 billion people could be climate change refugees, according to Geisler’s study. That number could reach 2 billion by 2100.

Not Just for the Birds: Higher Ground

Writing in the Washington Post, Elizabeth Rush, author of “Rising: The Unsettling of the American Shore,” suggests that coastal residents should take a lesson from the roseate spoonbill. For most of the past century, this striking pink shorebird has made a habitat in the Florida Keys. But for the past decade, as rising wetland levels have made finding food more difficult, the spoonbills have been steadily abandoning their historic nesting grounds for higher ground on the mainland. She writes:

Adding several centimeters of water into the wetlands where spoonbills traditionally bred (as has occurred over the past 10 years in the Florida Bay, thanks to wetter winters and higher tides) significantly changed the landscape, eliminating the habitats where these gangly waders had long found dinner. When the spoonbills realized it was no longer possible to live on the Florida Keys, they left.

But humans can’t move to higher ground and build new homes as easily as the spoonbill. Rush contends that “legal and regulatory conditions don’t make moving away from increasingly dangerous coastal areas easy.” She argues that, to avoid loss of life and economic value, governments at local, state and federal levels, as part of climate adaption, must “start financing and encouraging relocation.”

Roseate spoonbills at J.N. Darling National Wildlife Refuge in Florida. For the past decade, spoonbills have been moving out of the Florida Keys to higher ground. (image: Harold Wagle, finalist, National Wildlife Refuge Association 2012 photo contest/USFWS/Flickr)

In New York, some residents impacted by Hurricane Sandy took matters into their own hands, forming grassroots “buyout committees” to raise awareness about the perils of coastal life, even knocking on doors to gauge residents’ interest in relocating. Eventually, the relocation activists got the attention and support of Governor Andrew Cuomo: In 2013, he released funds from the federal Hazard Mitigation Grant Program to buy out homes across three Sandy-impacted areas in Staten Island.

“[T]hose homes would be knocked down, giving the wetlands a chance to return so they might provide a buffer against storms to come,” Rush writes, adding that since Sandy, around 500 residents have applied for government buyouts—now “entire neighborhoods are being demolished along the island’s shore.”

Risky Business: Flood Insurance

One “exit barrier” has to do with a 49-year-old program called the National Flood Insurance Program. Under the current law, homeowners are required to rebuild on their land—even after suffering through multiple floods. “Through the National Flood Insurance Program, we know there are about 30,000 properties that flood repeatedly,” said Rob Moore, senior policy analyst for the NRDC’s water program. “On average, these properties have flooded about five times.” Only around one percent of these properties carry flood insurance, reports NPR, but have been responsible for about 25 percent of the paid claims.

Jennifer Bayles, a homeowner in the Houston metro area who was interviewed last week on NPR, paid $83,000 for her house in 1992. After the first flood in 2009, insurance paid her $200,000, then an additional $200,000 following the next flood. Now, post-Harvey, she expects to receive around $300,000.

Houston residents use an inflatable swan to move items from a flooded house in the aftermath of Hurricane Harvey. (image: IrinaK/Shutterstock)

When a program pays out billions of dollars for just a handful of repeat customers, some argue that rebuilding simply isn’t cost-efficient. Rush points to a recent Natural Resources Defense Council study that found, “in most cases, it is less expensive to buy out these homes than it is to cover the cost of repairing and rebuilding after ever-more-common floods.”

Another problem is a lack of funding. The National Flood Insurance Program is nearly $25 billion in debt due to this season’s massive hurricanes. In a recent press briefing, Roy E. Wright, the deputy FEMA administrator in charge of the program, said his agency estimates it will pay Texas policyholders some $11 billion in flood claims for Harvey alone. But NFIP has only $1.08 billion of cash to pay claims. That amount, reported Bradley Keoun of TheStreet.com last week, is “down by a third in less than three weeks—and a $5.8 billion credit limit from the U.S. Treasury Department.”

Congress is set to vote soon on whether to reauthorize the flood program. “Even though we reauthorized it for three months, and extended it, it’s gonna run out of money probably in October,” Rep. Tom MacArthur (R-NJ) told Rollcall earlier this month. MacArthur, who sits on the House Natural Resources Subcommittee on Water, Power and Oceans, said Congress will have to authorize additional financial support to the program, noting that extra funds “must come with reform.”

What kind of reform remains to be seen. Rush proposes lawmakers eliminate the requirement that claim filers must rebuild near the line of devastation:

[T]he program could offer discounted flood insurance to homeowners in the highest-risk areas, with a caveat: In return for lower premiums, those homeowners would agree to accept buyouts if their properties were damaged during a flood. This would help keep insurance rates affordable for low- and middle-income homeowners (a daunting task given that the program is both federally subsidized and tens of billions of dollars in debt) while encouraging folks to move out of harm’s way.

Risky Proposition: Climate Denial

House Financial Services Chairman Jeb Hensarling (R-Texas), a longtime critic of NFIP, argues that the program amounts to a federal subsidy that spurs human development in flood zones. “After Harvey and Irma,” he told Rollcall, “it would be insane for the federal government to simply rebuild repetitive loss homes in the same fashion, in the same place.”

In an interview Thursday on CNBC, he said:

If all we do is force federal taxpayers to build the same homes in the same fashion, in the same location and expect a different result, we all know that’s the classic definition of insanity…. Maybe we pay for your home once, maybe even pay for it twice, but at some point the taxpayer’s got to quit paying and you’ve got to move.

“The NFIP in its current form is unsustainable and perverse,” Hensarling said, in a written statement.

Perhaps. But what’s also unsustainable and perverse is denying the role of climate change, not only in storm activity, but in the rising sea levels that make flooding worse: Hensarling’s poor climate voting record garnered him a spot on Vice Motherboard’s “Texas Climate Change Deniers” list. As the Sun Herald, a Mississippi Gulf Coast newspaper, recently put it, “Climate change denial and our love of the beach could sink the National Flood Insurance program.”

Predictably, Donald Trump dismissed the notion that climate change played a role in the frequency and intensity of superstorms like Harvey and Irma. When asked about climate change by reporters aboard Air Force One after touring the devastation of Florida’s west coast, Trump insisted:

If you go back into the 1930s and the 1940s, and you take a look, we’ve had storms over the years that have been bigger than this….So we did have two horrific storms, epic storms, but if you go back into the ’30s and ’40s, and you go back into the teens, you’ll see storms that were very similar and even bigger, OK?

But for coastal residents impacted by these massive storms—and for the vast majority of scientists—it’s not OK. Penn State atmospheric scientist Michael Mann connects the dots between climate change and the impact of Hurricane Harvey:

There are certain climate change-related factors that we can, with great confidence, say worsened the flooding. Sea level rise attributable to climate change…is more than half a foot over the past few decades. That means that the storm surge was a half foot higher than it would have been just decades ago, meaning far more flooding and destruction. This map shows the odds of floods in Florida at least as high as historic once-a-century levels, coming by 2030. Most or all of the rise can be attributed to global warming. (credit: Climate Central)

Endangered: Ocean Economies

There’s also the economic impact of losing shorelines. The U.N. estimates that the so-called ocean economy, which includes employment, marine-based ecosystem services and cultural services, is between $3 to $6 trillion per year.

Coastal areas within 100 kilometers (62 miles) of the ocean account for more than 60 percent of the world’s total gross national production. For the economies of developing nations, these regions are especially crucial. A big part of that coastal production is food. As the sea gobbles up fertile seaside land and river deltas, feeding the rapidly escalating human population is going to get that much more difficult.

Fishermen in Lagos, Nigeria. The coastline of Lagos state is about 110 miles long and supports the livelihoods of thousands of fishermen. (image: Heinrich-Böll-Stiftung/Flickr)

The future of tourism is also a major concern, particularly small island states, where tourism generally accounts for more than a quarter of GDP. For some islands, that amount may soon have to be wiped off the balance sheet. Just last year, five islands in the Solomon Island archipelago disappeared to the rising sea.

But economic losses due to extreme weather and climate change are also a major issue for developed nations; according to preliminary estimates, Hurricane Harvey caused up to $200 billion in damage.

Retreat or Rebuild?

People may enjoy the coasts, beaches, surf and sand. But by emitting greenhouse gases at an unsustainable rate, we’re losing these cherished ecosystems to the rising seas and superstorms. Perhaps we should give the coasts back to nature. By letting key coastal ecosystems return to their natural states, mangrove forests and other vegetated marine and intertidal habitats can act as bulwarks against the rising seas and hurricanes.

Like forests, these coastal areas are powerful carbon sinks, safely storing around a quarter of the additional carbon dioxide from the burning of fossil fuels. Crucially, they also help protect communities and wildlife near shores from floods and storm surges. As people move inland, natural ecosystems could reclaim shorelines. “Retreat,” Rush declares, “is slowly gaining traction as a climate change adaptation strategy.”

Mangrove forests, like this one on Lake Tabarisia in Indonesia, help reduce storm surges and flood damage while stabilizing shorelines with their extensive root systems. Mangroves have been systematically eliminated worldwide to make room for human development and shrimp aquaculture. (image: Mokhamad Edliadi/CIFOR/Flickr)

Moving people out of flood zones—and rewilding coastlines and bringing wetlands back—could be an area where policymakers and conservationists could find common ground. It also means rethinking the way cities are designed; when it comes to urban planning, city planners have generally not taken natural systems into account.

Writing on AlterNet, Mary Mazzoni looked at how the mismanagement of Houston’s natural ecosystem increased the amount of flooding from Hurricane Harvey, pointing out that by paving over wetlands, which are able to absorb a great amount of flood water, the city left itself vulnerable to disaster.

She notes that the “relative lack of regulatory hurdles—Houston is the largest U.S. city without zoning laws—allowed development to continue more or less unchecked…the wetlands loss documented in [a] Texas A&M study is equivalent to nearly 4 billion gallons in lost stormwater detention, worth an estimated $600 million.”

“‘Conquering’ nature has long been the western way,” writes Canadian environmentalist David Suzuki. “Our hubris, and often our religious ideologies, have led us to believe we are above nature and have a right to subdue and control it. We let our technical abilities get ahead of our wisdom. We’re learning now that working with nature—understanding that we are part of it—is more cost-effective and efficient in the long run.”

In our new normal, one way to work with nature might be to let her have her coastlines back.