Can We Rely on Mangroves to Provide a Line of Defense against Sea Level Rise Flooding?

One of the greatest challenges involved in combatting sea level rise flooding is finding solutions that will stand the test of time. Some coastal communities have been seeking natural solutions, such as sand dunes, wetlands and native vegetation, to hold back ever-higher tides and storm surges. Planners recognize the ability of natural ecosystems to self-regulate and adjust to sea water as it exerts pressure to march inland.

In the U.S., some southern Atlantic and Gulf Coast communities have been including mangroves in their action plans. They’re counting on the thick, leafy forests that thrive in shallow coastal waters to not only absorb and store some of the carbon released into the atmosphere by the burning of fossil fuels that’s driving global warming but to act as a buffer against storm surges and higher tides. They also hope to benefit from the mangroves ability to capture sediments and build land when the seas are trying to erode it away.

The idea sounded great until a recent study led by Macquarie University in Australia found that unless humans reduce the release of greenhouse gases, the seas will soon rise at a faster pace than the mangroves can accommodate. With sea level rise accelerating, due to ocean expansion and the ever-quickening pace of ice melt in Greenland and Antarctica, the mangroves could start to disappear within the next thirty years.

Unfortunately, real estate alone won’t pay the price when mangroves are gone. Mangroves provide a valuable nursery for birds, fish and other organisms. Their loss will endanger whole ecosystems.

The Loss of Louisiana Marshes to Sea Level Rise Puts New Orleans Real Estate at Risk

Over the course of the last several decades, people have come to recognize the value of coastal marshlands as both incubators of aquatic birds and marine life and as buffers to floods and storm surges that can quickly inundate valuable real estate. A recent study published on the American Academy for the Advancement of Science’s Science Advances website reached the troubling conclusion that sea level rise is occurring at such a fast pace that the marshes that protect New Orleans and surrounding communities could vanish beneath the waves in the next fifty years.

Scientists studied over 8,000 years of marsh history to determine that the marshes have reached a “tipping point” where they are being consumed by the ocean faster than they can adjust to higher sea levels. The study’s lead scientist, Torbjorn Tornqvist, a professor of geology at Tulane University, told the Washington Post that even with efforts to reduce the production of earth-warming greenhouse gases, the marshland’s fate could be sealed. “We know the rate of sea level rise, even with the best action you can imagine, it’s still going to ramp up further,” he said. “Given the slowness of the ocean responses, it’s going to last for a very long time.”

The ocean has been gnawing away at the protective marshlands for decades. Experts blame the loss on the penning in of the Mississippi River channel, which used to spread land-building sediment broadly across the river delta, and on channels cut through the marshes for petroleum company pipelines. Louisiana is trying to reverse some of the damage by diverting some of the river’s sediment-rich flow out of the manmade channel and onto adjacent lands.

Professor Tornqvist sees this as a way to buy time that ultimately won’t save the city from inundation. “I think a couple of decades is incredibly valuable,” he said, “because it could be the difference between a somewhat managed retreat verses complete chaos.”

The researchers believe their study could prove valuable to all coastal communities that rely on marshlands as a buffer against sea level rise flooding and storm surges. “Our findings highlight the need for consideration of longer time windows in determining the vulnerability of coastal marshes worldwide,” they wrote in their study abstract.

The takeaway for buyers and owners of real estate in coastal areas protected by marshlands is to recognize that they’re not wastelands but a critical part of the ecosystem that protect their property from flooding. With that in mind, it’s important for them to learn about the health of the local marshes as well as their predicted life-expectancy under pressure from sea level rise.

Human Activity, not Earth’s Distance from the Sun is Driving Sea Level Rise

Scientists at Rutgers University have released a study that proves humans burning fossil fuels are creating global warming, not, as some people contend, Earth’s proximity to the sun.

In the past, slight changes in Earth’s orbit drove global warming that resulted in glacial ice melt. In the modern era, the scientists found that a human-driven rise in carbon dioxide — a powerful greenhouse gas — is warming the planet. As a result, glaciers — especially in Antarctica and Greenland — are melting and the oceans are expanding. This is causing the sea levels to rise.

The scientists reached their conclusion by reconstructing the history of Earth’s glacial and ice free periods. They found that sea level declined 20,000 years ago during the last glacial period then it began rising rapidly as the ice age ended. Sea level rise gradually slowed to the point where it was nearly at a standstill in 1900. The researchers said it then started rising again due to human activities, and it has been rising since.

Kennth G. Miller, the study’s lead author and a Distinguished Professor in the Department of Earth and Planetary Sciences at Rutgers, told Rutgers Today: “Our team showed that the Earth’s history of glaciation was more complex than previously thought. Although carbon dioxide levels had an important influence on ice-free periods, minor variations in the Earth’s orbit were the dominant factor in terms of ice volume and sea-level changes – until modern times.”

The Rutgers research puts another nail in the coffin of climate change deniers who refuse to recognize that the planet is warming and the seas are rising due to human activity. When combined with the pile of scientific evidence that proves the seas are rising at an ever-accelerating rate, it’s clear that governments and buyers, sellers and real estate agents in coastal areas need to stay up to date on this critical issue that is already threatening their way of life.

Over 100 Climate Experts Predict Over 4 Feet of Sea Level Rise Possible by 2100

In a survey published this month, 106 climate experts predicted sea levels could rise by as much as 4.2 feet by 2100. The study, released by Nanyang Technological University in Singapore, has bad news and potential good news, depending on how successful humans are at reducing the release of greenhouse gases.

First the bad news. The experts estimate that if the burning of fossil fuels raises global temperature by 8.1 degrees Fahrenheit, sea levels could rise by 1.9 feet to 4.2 feet. The good news is that if greenhouse gas emissions are reduced to the point where the global temperature is kept at or below 3.6 degrees Fahrenheit, seas would only rise by about 1.6 feet. (Considering that real estate and critical infrastructure in many coastal areas is already being inundated by sea level rise measured in inches not feet, “good news” is a certainly a relative term.)

The wide range in sea level rise estimates is due, in part, to the challenge of predicting the rate at which ice sheets in Antarctica and Greenland will melt. Satellite observations are indicating that they’re melting at an ever accelerating rate.

Dr. Andra Garner, the study’s co-author and a professor of environmental science at Rowan University, told the Express newspaper that the survey results should help government plan for sea level rise. “This provides a great deal of hope for the future,” she said, “as well as a strong motivation to act now to avoid the more severe impacts of rising seas.”

The takeaway from this study is that property buyers, owners and real estate agents need to pay attention to the threat sea level rise poses to their communities to make informed decisions. Sea level rise flooding can affect property value, maintenance costs, taxes and insurance rates, and the mortgage market.

Planners Can’t Afford to Overlook Groundwater-Driven Sea Level Rise Flooding — University of Hawaii Study

Researchers at the University of Hawaii at Manoa studied three different sources of sea level rise flooding and found groundwater inundation — a rising of the water table to the surface due to the pressure created by sea level rise — is the major threat to urban Honolulu.

To arrive at this conclusion, the researchers studied the likely causes of sea level rise flooding over the next few decades in Honolulu. They did this by producing flood maps that considered the threats posed by sea level rise-driven groundwater inundation, reverse municipal drainage — where ocean water flows backward through the drainage system and rises up through stormwater drainage grates — and direct marine inundation — where ocean water flows in from the sea. Among their surprising findings, they determined that direct marine inundation represented only 3 percent of the overall near-term threat.

The researchers said their findings clearly indicate that seawalls, one of the most popular approaches to holding back sea level rise flooding from damaging real estate and critical infrastructure, such as roads and water and sewer pipes, won’t be able to stop groundwater inundation. They said the only options in areas impacted by groundwater inundation will be to adapt to the flood waters or abandon the affected area.

“What this means for the future of Honolulu is that we need to consider each different type of flooding individually and really think about how we’re adapting to each one,” said Shellie Habel, a coastal geologist with the University of Hawaii Sea Grant College Program.

The University of Hawaii report should act as a wake-up call to coastal areas everywhere that have high water tables and porous bedrock, like South Florida. The groundwater inundation threat must be considered before enormous amounts of money are invested in sea walls that ultimately won’t be able to protect real estate and critical infrastructure from sea level rise flooding. (Photo courtesy of School of Ocean and Earth Science Technology, University of Hawaii at Manoa)

Antarctica and Greenland Ice Melt Raised Sea Levels a Half Inch In the Last 16 Years — NASA Report

NASA scientists crunched data from satellite missions to determine that ice melt in Antarctica and Greenland over the last 16 years raised sea levels about half an inch. Put another way, the researchers said both locations contributed 5,000 gigatons of water to the oceans which is enough to fill Lake Michigan.

Ice melt and ocean expansion due to global warming are the primary contributors to sea level rise. Experts are concerned that the rate of melting is picking up pace. Helen Fricker, a glaciologist at the University of California-San Diego, told National Public Radio, “How much ice we are going to lose, and how quickly we are going to lose it, is a really key thing that needs to be understood, so that we can plan.”

There are two main forces driving the melting in Antarctica and Greenland. In Antarctica, warming oceans are melting floating ice shelves, which is allowing land based ice to flow into the ocean. In Greenland, warmer atmospheric temperatures are melting ice and creating run-off. At the same time, the warmer air is also causing glacial ice to calve off and fall into the ocean.

If all the ice melted in Greenland alone, scientists estimate global sea levels would rise 23 feet. Fricker told NPR, “There’s a lot of infrastructure and airports and people that live right on the ocean, and these people are going to feel the effects of sea level rise that’s resulted because the ice sheets have melted.”

Global Consultant Recommends Steps to Protect Florida Real Estate Value from Sea Level Rise Flooding

McKinsey & Company, a global consulting firm, released a report this week that analyzes the risk sea level rise flooding poses to billions of dollars worth of Florida’s residential real estate and recommends steps that could be taken to mitigate the damage.

The report, titled “Will mortgages and markets stay afloat in Florida?”, starts by stating the simple fact that Florida’s unique location — in a hurricane-prone zone — and geology — extra low elevation with a porous limestone foundation that allows sea water to move freely — makes it very susceptible to sea level rise flooding. In fact, the authors cite a First Street Foundation study that concluded sea level rise will increase the number of days that many coastal areas experience tidal flooding each year from a few days today to 200 days a year by 2050. In addition, the average annual damages from storm surges will itself surge from $2 billion today to up to $4.5 billion by the middle of this century.

The report goes on to discuss how sea level rise is already depressing home values in areas that experience sea level rise flooding compared with those that don’t. “About 25,000 homes in Florida already experience flooding at frequencies of more than 50 times per year (almost once a week on average),” according to the report. “With rising sea levels, 40,000 coastal properties representing $15 billion of value could run this risk by 2030, and 100,000 properties worth $50 billion by 2050.”

The threat to the value of Florida’s residential real estate isn’t posed only by direct flooding, either. The report says as buyers are increasingly made aware of the flooding and the expenses involved in owning a property in a flood zone, prices will likely drop. Buyers could also balk at the higher insurance premiums and taxes that are sure to be levied as a result of flooding. A final point of pressure is the mortgage market. With the risk of flooding increasing every year, experts are wondering how long mortgage providers be willing to write 30-year-mortgages — or even 15 year mortgages, for that matter — for high risk properties when the owners might never pay back the loans.

The report authors offer a few potential solutions that could help mitigate the risk. Among their recommendations are that: 1. Real estate markets become more transparent about the risk of sea level rise flooding, so buyers don’t lose confidence in the market; 2. More money be spent on projects needed to upgrade the infrastructure — such as sea walls and storm sewers — needed to fend off the flooding ; and 3. Policy makers, engineers, investors and community organizations band together in groups to decide which properties to protect from sea level rise flooding and which to abandon.

In the end, the authors write that “While the state and communities face hard choices in the face of rising sea levels and worsening hazards, planning today can help manage the consequences and minimize the costs of climate change in the future.”

It’s clear from this report that the day of reckoning is here for buyers, sellers, owners and real estate agents in coastal communities. Understanding the roles played by individual property owners, governments, insurers and mortgage providers in the health of a real estate market impacted by sea level rise flooding is critical to protect your financial future.

Greenland’s Ice Sheet Melts at Record Rate in 2019, Scientists Worry the Weather System that Caused it will Double the Rate of Sea Level Rise

Scientists published a study today that concluded that Greenland’s ice sheet melted at a record rate last summer due not just to the heat generated by general global warming but because of a high pressure area that brought lots of sunshine and warmer days to the region.

The researchers analyzed weather data and found that Greenland experienced 63 summer days ruled by the high pressure system, which is double the normal 28 days of high pressure logged between 1981 and 2010. This fueled the loss of 600 billion tons of water, which is estimated to contribute up to .06 inches of sea level rise globally.

The scientists worry that past predictions for the rate of ice sheet loss in Greenland did not take into consideration the impact high pressure areas could have on the rate of melting. If it speeds up, coastal areas with millions of inhabitants and trillions of dollars worth of real estate could be inundated a lot sooner than expected. Marco Tedesco, a researcher at Columbia University who led the study, told Reuters: “We’re destroying ice in decades that was built over thousands of years. What we do here has huge implications for everywhere else in the world.”

Greenland and Antarctica are home to the world’s largest ice sheets. If all the ice in Greenland melted, sea levels would rise by up to 23 feet.

Researchers say the study on high pressure and accelerated ice melt is further evidence that humans need to reduce the burning of fossil fuels to save coastal communities.

Scientists Identify the Greatest Obstacle to Educating Real Estate Owners about the Threat of Sea Level Rise Flooding

Social scientists studying the effectiveness of climate change communications strategies wrote an opinion piece that concluded personal financial interest is the leading cause of real estate owners in coastal areas denying that sea level rise flooding poses a threat to their property.

Risa Palm, a professor of Urban Studies and Public Health at Georgia State University, and Toby W. Bolsen, an associate professor of American politics in the political science department at Georgia State, wrote the column for The Conversation. They said they showed property owners who lived in South Florida neighborhoods at-risk of sea level rise flooding and hurricane storm surge maps produced by First Street Foundation that indicated that their properties could be inundated or be impacted in other ways by floodwaters in the next 15 years. Their homes were also identified as being at risk of devaluation due to their proximity to the threat of sea level rise flooding.

“Surprisingly, we found that those who had viewed the maps were on average, less likely to say they believed that climate change was taking place than those who had not seen the maps,” Palm and Bolsen wrote. “Further, those who saw the maps were less likely than those survey respondents who had not seen the maps to believe that climate change was responsible for the increased intensity of storms.”

The researchers said Republicans surveyed “had the strongest negative response to the maps.” In fact, they found “party identification was the strongest predictor of general perceptions of climate change and sea level rise.” Ultimately, however, they said, “the majority of homeowners denied that there was a risk to their property values, regardless of political affiliation.”

In the end, Palm and Bolsen recommended that governments and organizations trying to educate the public about the threat of sea level rise flooding not only use easy to understand facts but a “nuanced approach” to change the way the information is perceived. Or, as they said, “As advertisers well know, it takes more than facts to sell any product.” To get people to stop and pay attention, the information also needs “an emotional hook.”

This study may explain why buyers continue to purchase property and owners continue to hold real estate that scientists have clearly identified as at-risk of sea level rise flooding within the next couple of decades. Unfortunately, turning a blind eye to this factual information won’t save them as the seas continue to rise at an ever-quickening pace.