Union of Concerned Scientists Try to Calculate Cost of One Meter Sea Level Rise

July 23, 2017 – To ignore sea level rise is to ignore the most visible evidence of global warming. Our seas are rising 3 to 4 millimeters per year. That’s not a big number based on annual increments. But over a decade that amounts to 3 to 4 centimeters, over 50 years, 15 to 20 centimeters, and over 100, 30 to 40 centimeters. If you think in feet we are talking about an inch to an inch-and-a-half per decade, and 10 to 15 inches over a century. With rising water that slow you would think we could build up shorelines, raise coastal homes on stilts, elevate roadways, and do many other infrastructure enhancements to minimize the potential damage.

But if your government denies the evidence then nothing gets done. Do nothing then you have reason to be very afraid if you live in lowland areas near coastlines. For example, think about a beachfront property you have just bought that lies just beyond a low beach on one of America’s beautiful East and Gulf Coast barrier islands. Think about the premiums you will pay for flood damage, and how much they will rise as the century unfolds. And what happens when the insurers no longer provide flood coverage? Will you be able to resell? Or will you take your chances until your home gets washed away?

Anders Levermann of the Potsdam Institute for Climate Impact Research has been quoted stating, “No one has to be afraid of sea level rise if you’re not stupid. It’s low enough that we can respond. It’s nothing to be surprised about, unless you have an administration that says it’s not happening.”

Getting blindsided because the government chooses not to accept evidence could mean a 30% decline in the global economy as low-lying regions where much of humanity lives is abandoned over the next few centuries.

Based on a 2015 study on future coastal population growth and sea-level rise looking out to 100 years hence, the authors calculated that the regions of the world with the highest degree of exposure would be in Asia and not in Europe or North America. Shanghai and much of coastal China, Bangladesh, India, Indonesia, and Vietnam would be most impacted. The populations of Nile delta and Amazon basin would also suffer. And finally most of the world’s megacities which are almost all located along coastlines.

Managing the Coastlines Going Forward

We have two options as sea levels rise. One is to build up our coastal defenses, raise berms, plant mangroves, build seawalls and tide gates. The cost of these projects will amount to hundreds of billions if not trillions of dollars. The other option is to move coastal populations inland and in measured fashion abandon our coastal cities and shorelines.

For the people of New York City, abandonment seems like an insane option. The same can be said for San Francisco or Los Angeles. But what about cities like New Orleans, Miami or Boston? Today the latter three or the most vulnerable in North America when it comes to rising sea levels.

But what about cities like New Orleans, Miami or Boston? Today these latter three or the most vulnerable to rising sea levels in North America.

Take a look at New Orleans and its climate change adaptation strategy. Already below sea level, New Orleans was a victim of Hurricane Katrina, a once in a century storm that inundated much of the city. So the city has a plan to cope with rising water which includes coastal wetland restoration with a target date of 2030 for completion. In place are new storm surge barriers built by the Army Corps of Engineers after Katrina. Dikes and levees have been restored or strengthened. Housing regulations now require new homes to be built higher. Is this enough to ensure New Orleans will be here in 2100 and beyond? Many climate scientists seriously doubt it.

Miami, neighbouring Fort Lauderdale to the north, and communities to the cities south represent the fourth-largest most vulnerable population on the planet when it comes to sea level rise. A recent task force focused on planning to 2060 and made five recommendations including a capital plan with measurable timelines to deal with coastal inundation. Where sea level rise will be gradual, storm surges of significant height remain a continuing danger to Miami and its surroundings. Sea levels by 2060 may only rise 15 to 20 centimeters, but a Category 3 hurricane could create storm surges 10 times that height.

Miami doesn’t have the dikes and flood barriers of New Orleans. The city’s urban spread makes the construction of such economically prohibitive. But what Miami does have is the Everglades and restoration of this extensive wetland plus development of coastal wetlands and mangroves where Miami’s beaches are today could help the city survive to the end of the century at least.

In the task force’s conclusion it states, “we believe that without a professionally well thought out adaptation plan in place, we risk losing insurability and financial support for our future.” The mention of insurance is interesting because the reinsurance industry is looking at Miami and seeing an underwriting nightmare unfolding. Trillions of dollars are at stake and the Munich Re and Swiss Re’s of the world are not interested in backing insurance companies issuing flood policies to homeowners and businesses so at risk.

Boston is ranked the eighth most vulnerable city to climate change on the planet. Its government began drafting a climate action plan back in 2007. , The Boston Urban Land Institute in its reports sees Boston’s downtown reclaimed tidelands as most vulnerable. So Boston is considering becoming the Venice of North America as sea levels rise. Neighbourhoods may find themselves completely surrounded by canals rather than streets with Boston by end of century looking far different from what we see today.

The Numbers

The Union of Concerned Scientists has studied Michael Bloomberg’s 2014 Risky Business Report, a climate assessment for the United States that quantifies economic risk. It calculates the following:

• By 2050 between $66 billion and $106 billion worth of existing coastal property will likely be below sea level nationwide, with $238 billion to $507 billion worth of property below sea level by 2100.
• That by 2100 that number will have grown to $701 billion worth of existing coastal property below mean sea levels and $730 billion of additional property at risk during high tides.

The scientists have their own number which encompasses the entire planet. It is far steeper with sea level rise and flooding by 2050 impacting properties to the tune of more than $1 trillion per year. That’s 2050, not 2100 or some even more remote day. If you have just given birth to a child when they reach the age of 33 their world will be far poorer because the current U.S. administration has chosen to believe climate change and sea level rise are a hoax.

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