Earth Wise

A look at our changing environment.

You are here: Home / Archives for rising seas

rising seas

Mangrove Trees And Climate Change | Earth Wise

By Leave a Comment

Mangrove trees are small trees that grow in coastal saline or brackish water at tropical and subtropical latitudes.  Many mangrove trees can be identified by their dense tangle of prop roots.  These roots make the trees appear as if they are standing on stilts above the water.  The tangle of roots allows mangrove trees to handle the daily rise and fall of tides and to slow the movement of tidal waters.  

Mangrove forests provide many ecosystem services, including stabilizing the coastline by reducing erosion from storm surges, waves, and tides.  The intricate root system of mangrove trees are attractive to fish and other species seeking food and shelter from predators.  Mangrove forests also store large amounts of carbon.     

But according to a new study recently published in the journal Science, mangrove trees won’t survive sea level rise by 2050 if greenhouse gas emissions aren’t reduced.  

Using sediment data from 78 locations over the last 10,000 years, an international team of scientists led by Macquarie University in Australia estimated the chances of mangrove trees survival based on the projected rates of future sea-level rise.

When sea level rise rates exceeded 6 millimeters per year, which is similar to estimates under high-emissions scenarios for 2050, researchers found that mangrove trees were unlikely to keep pace with the rising water levels.  But when the annual increase was 5 millimeters or less – which is the projected low-emissions scenario this century – mangrove trees are much more likely to survive. 

These findings underscore the importance of reducing greenhouse gas emissions to mitigate rapid sea level rise.  The future of mangrove trees may depend on it.  

**********

Web Links

Mangrove trees won’t survive sea-level rise by 2050 if emissions aren’t cut

Photo, posted December 17, 2012, courtesy of Edward Stojakovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Keeping Charleston Dry | Earth Wise

By Leave a Comment

Charleston, South Carolina is visited by millions of tourists each year.  The town is a glimpse into the past, showcasing antebellum mansions, row houses, historic African American churches and scenic harbor views from a Civil War-era promenade.

Charleston is also visited more and more by water from rising seas and increasingly powerful storms.  The city is essentially drowning in slow motion and may soon face an existential threat to its survival.

Charleston has a harbor and three rivers and water from all these sources leaks in at every bend and curve, fills streets, disrupts businesses, and rushes into homes during storms.  Million-dollar antebellum mansions, built on spongy marsh and old tidal creeks, flood repeatedly.

City officials have endorsed a plan by the U.S. Army Corps of Engineers to wall off the historic downtown with an 8-mile-long seawall that would cost nearly $2 billion.  The proposed barricade is just one of many proposed projects to build seawalls, surge gates, levees, and other barriers to defend U.S. coastal cities in an era of rising seas and climate-fueled floods and storms.  A proposed flood wall in Miami would cost federal taxpayers $8 billion.

Researchers generally agree that sea levels are likely to rise by at least 3 feet by the end of the century.  Some experts believe the rise will be much greater.  So, a key question is whether these barriers will actually keep out the water.  Critics of many of the proposed solutions contend that they are doomed to fail.

Flooding has caused nearly $1 trillion worth of damage along the East and Gulf coasts over the past 40 years.  And things are almost certain to get worse in Charleston and other coastal cities.

**********

Web Links

Fortress Charleston: Will Walling Off the City Hold Back the Waters?

Photo, posted October 7, 2015, courtesy of Jeff Turner via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Companies Promise Climate Action | Earth Wise

By Leave a Comment

A growing number of major corporations are making promises on climate and the promises are getting more ambitious and for faster action.  More companies are disclosing their carbon emissions and more of those companies have emissions reduction targets. 

There has also been an acceleration in the rate at which companies set so-called science-based targets, which are specific, measurable carbon reduction goals that align the company with the Paris Agreement.  Among the hundreds of companies with such targets are Coca-Cola, Nike, Best Buy, Walmart, and Hilton Hotels.  According to one analysis, the number of Fortune 500 companies with concrete, ambitious carbon targets quadrupled in the past four year to 23%.

Environmental advocates have been pressuring companies for decades, but companies seem to be far more proactive now despite the fact that the U.S. government has largely dropped the ball on climate issues.

The reasons include the fact that the effects of climate change are becoming clearer to companies.  Wildfires, rising sea levels, droughts and other aspects of the crisis both make headlines and affect business operations.

Meanwhile, solar and wind energy have gotten significantly cheaper, making it more attractive for companies to shift away from fossil fuels.

At the same time, investors are increasingly asking companies to act on climate issues.  Consumers, employees, and the general public are increasingly demanding action and even children are adding to the pressure to act.

Making these commitments is one thing; following through on them and sticking to them is another.  There are real concerns that there is a great deal of green-washing going on among companies trying to project a favorable image.  In any case, if companies really want to lead on climate, they need to put their money where their mouths are.

**********

Web Links

Better Late Than Never? Big Companies Scramble To Make Lofty Climate Promises

Photo, posted June 22, 2016, courtesy of Mike Mozart via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coastal Plants And Climate Change | Earth Wise

By Leave a Comment

Rising sea levels and the increased frequency and intensity of extreme weather events are leaving observable effects on beaches, cliffs, and coastal infrastructures all around the world.  But a new study suggests that the impact of climate change on coastal plant communities needs more attention. 

According to research recently published in the journal Annals of Botany, coastal plants are a critical element of global sea defense.  But coastal plants are increasingly under threat from flooding, erosion, and other human-induced effects of climate change.  Habitats like salt marshes, mangrove forests, sand dunes, and kelp beds make important contributions  to coastal protection.

The research was led by scientists from the University of Plymouth, in conjunction with researchers at Utrecht University and Manchester Metropolitan University.

The study follows a recent assessment by the Intergovernmental Panel on Climate Change, which found that anthropogenic climate change poses a severe threat to estuaries and coastal ecosystems.  

Conservative estimates of the capital investments needed to combat rising seas and intensifying storms run into the hundreds of billions of dollars in the coming decades.  However, coastal vegetation could offer a dynamic, natural, and relatively low-cost defense strategy at a fraction of the cost when compared with the cost of so-called hard defenses like concrete walls and barriers. 

According to the research team, identifying the key species and habitats for coastal defense and how coasts can be protected and promoted is critical.  More long-term monitoring is also needed in order to better understand and predict where and how storms and other effects of climate change will impact coastal ecosystems. 

**********

Web Links

The gathering storm: optimizing management of coastal ecosystems in the face of a climate-driven threat

Losing coastal plant communities to climate change will weaken sea defences

Photo, posted September 14, 2018, courtesy of Dennis Jarvis via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Rising Threat Of Rising Seas | Earth Wise

By Leave a Comment

Global sea level rose by about 6 inches during the 20th century.  It is currently rising more than twice as fast and accelerating.  The rate of rise was 2.5 times faster from 2006 to 2016 than it was for nearly all of the 20th century.

Sea level rise occurs when glaciers and ice sheets lose mass.  Much of that meltwater comes from Greenland and Antarctica.  But levels also rise because, as water warms, it expands.  Added to that are the effects of human activities such as groundwater depletion and a geological phenomenon called isostatic adjustment that is going on in parts of the East Coast where the land is actually sinking.

In Atlantic Canada, sea level rise is outpacing the global average and has already led to boardwalks swamped by swelling tides, drowned forests, submerged wharfs, and threatened historic shoreline buildings.

Recent research suggests that globally, land now occupied by 300 million people could be affected by floods at least once a year by 2050 unless carbon emissions are significantly reduced, and coastal defenses strengthened.  (This new figure is more than three times higher than earlier estimates).

Researchers at Dalhousie University in Nova Scotia are studying nature-based strategies for mitigating the effects of the rising seas.  These include conserving or restoring coastal ecosystems like dunes, wetlands, and reefs which could provide protection at a lower cost than building seawalls and other man-made obstacles.  Wetlands, for example, can reduce the force of waves and act as obstacles to storm surges, while also trapping sediment and stemming erosion.  Wetlands also serve as important carbon stores, but it is estimated that roughly half of the world’s coastal wetlands have been lost over the past 100 years to human activity and extreme weather events.

**********

Web Links

The Looming Threat of Rising Sea Levels – And What We Can Do About it

Photo, posted February 14, 2015, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Excluding Climate Change From Infrastructure Planning | Earth Wise

By Leave a Comment

According to a new Trump administration proposal, federal agencies would no longer need to take climate change into account when evaluating infrastructure projects.  The proposed changes to the 50-year-old National Environmental Policy Act (NEPA) are aimed at speeding up approvals for highway construction, pipelines, oil and gas leases, and other major infrastructure projects.   

Under NEPA, federal agencies are required to consider how their proposed actions would affect everything from water quality to wildlife to greenhouse gas emissions.  They’re also required to understand how rising seas and other consequences of climate change might affect a given project.  These requirements have proven to be an obstacle to projects like the Keystone XL pipeline, for example. 

According to reporting in the New York Times, the administration also plans to narrow the range of projects that require environmental review in the first place.  That could make it more likely for projects to be approved without having to disclose plans to do things like cut down trees, discharge waste, or increase air pollution. 

The administration says that the changes would improve the environmental review and permitting process while ensuring a safe, healthy, and productive environment. Environmentalists say the proposed changes would weaken critical safeguards for air, water, and wildlife. 

The proposed changes to NEPA would revise the rules that guide the implementation of the law, as opposed to amending the act itself.  Once these proposed changes appear in the federal register, the public will have 60 days to comment on them. 

A decision on whether or not to weaken the nation’s benchmark environmental law is expected before November.

**********

Web Links

Trump Rule Would Exclude Climate Change in Infrastructure Planning

Photo, posted February 23, 2016, courtesy of Lissy Wild via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Which Cities To Save From The Changing Climate

By Leave a Comment

After several years of brutal flooding and hurricanes in the U.S., a distressing debate is emerging:  if there is not enough money available to protect every coastal community from the effects of global warming, how do we decide which ones to save first.

Recent research looked at the costs involved in providing basic storm-surge protection in the form of sea walls for all coastal cities with more than 25,000 residents.  That number was $42 billion.  Expanding the list to include communities smaller than 25,000 people would increase that cost to more than $400 billion.   Realistically, that is just not going to happen.

This particular study only looked at sea walls and no other methods for minimizing flood risk, such as moving homes and businesses away from the most flood-prone areas.   It also didn’t look at additional and costlier actions that will be required even with sea walls, such as revamping sewers, storm water, and drinking water infrastructure.

The facts are that many cities, especially small ones, will not be able to meet the costs facing them.  Those that can’t will depend on federal funding.  But even optimistically large proposals for federal infrastructure spending are likely to fall far short of the vast need.  Ultimately, the money will end up being spent where it can do the most good – even if it means that some places are left out.

But what criteria will be used to direct the money?  Economic value?  Historic significance?  Population?  Political influence?

This is a looming and massive issue whose chief obstacle may be that many officials refuse to acknowledge that it is happening.  This is the next wave of climate denial – denying the costs that we are all facing.

**********

Web Links

With More Storms and Rising Seas, Which U.S. Cities Should Be Saved First?

Photo, posted October 31, 2018, courtesy of Patrick Kinney via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Cost Of Rising Seas

By Leave a Comment

Coastal cities in the United States are grappling with the need for extensive infrastructure projects to protect against rising seas and worsening storms.  The cost of these projects will be enormous, and it is unclear how to pay to them.

Boston has many neighborhoods in low-lying areas, and it is estimated that $2.4 billion will be needed to protect the city from flooding.  The city abandoned plans to build a harbor barrier that would have cost $6 to $12 billion because it was economically unfeasible.

Charleston, South Caroline needs $2 billion to reduce flooding that occurs regularly during high tides.  The Houston, Texas area needs $30 billion to provide protection against a 100-year flood.  Hurricane Harvey caused $125 billion in damages in Texas in 2017.  New York City is considering a $10 billion storm surge barrier and floodgates to shield parts of the city from rising waters.

Florida faces the greatest exposure to flooding with an estimated $76 billion in costs to address some of its problems.

At the federal level, multiple agencies represent potential funding sources, but none offer the kind of money required to address the need.  This places a heavy burden on state and local governments.  Various states have passed legislation related to shoreline resiliency and flood abatement, but relatively little funding has been approved.  Some bond measures have passed, but the totals are small compared with what is needed.

Educating people about the costs of not doing anything or not doing enough soon enough is essential.  As Hurricane Katrina demonstrated, not spending a large amount of money on resilience can result in having to spend a colossal amount of money on recovery.

**********

Web Links

Who Will Pay for the Huge Costs of Holding Back Rising Seas?

Photo, posted December 26, 2013, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hundred-Year Floods Becoming One-Year Floods

By Leave a Comment

By definition, 100-year floods are intense flooding events that historically tend to happen once every 100 years.  Put another way, a 100-year flood has a 1 percent chance of happening in any given year.

According to new research published in the journal Nature Communications, rising global temperatures may turn 100-year floods into annual occurrences in parts of the United States.  The increase in severe coastal flooding events by the end of this century will be a result of rising sea levels and stronger, more frequent tropical storms and hurricanes.

The study, led by researchers at Princeton University and MIT, examined flood risk for 171 counties along the US East Coast and the Gulf of Mexico.  Their analysis concluded that 100-year floods will become annual events in New England.  In the US Southeast and Gulf of Mexico, counties could experience such floods as often as every year up to as seldom as every 30 years.

Previously, most analysis of coastal flooding has looked only at the impact of sea level rise on flood risk.  This new research combined the risk of rising seas with projected changes in coastal storms over the course of this century.  Data from the Gulf of Mexico revealed that the effect of stronger storms is comparable with or even more significant than the effect of sea level change for 40% of the counties studied.  So, neglecting the effects of storm climatology change is likely to significantly underestimate the impact of climate change in many places.

The hope is that more comprehensive flood risk data can be used to create more effective climate resiliency strategies all the way down to the county level.

**********

Web Links

100-Year Floods Could Soon Happen Annually in Parts of U.S., Study Finds

Photo, posted August 31, 2017, courtesy of the U.S. Department of Agriculture via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Beaches With Seagrass

By Leave a Comment

Almost a quarter of the Gross Domestic Product of places around the Caribbean Sea is earned from tourism.  Preserving the beaches in the region is an economic imperative.  With increasing coastal development, the natural flow of water and sand is disrupted, natural ecosystems are damaged, and many tropical beaches simply disappear into the sea.

With such high stakes, expensive coastal engineering efforts such as repeated replenishing of sand and the construction of concrete protective walls are common strategies.  Rising sea levels and increasingly powerful storms only increase the threat to tropical beaches.

Researchers from The Netherlands and Mexico recently published a study in the journal BioScience on the effectiveness of seagrass in holding onto sand and sediment along shorelines.

Seagrasses are so-named because most species have long green, grass-like leaves. They are often confused with seaweeds but are actually more closely related to flowering plants seen on land. Seagrasses have roots, stems and leaves, and produce flowers and seeds. Seagrasses can form dense underwater meadows and are one of the most productive ecosystems in the world. Seagrasses provide shelter and food to an incredibly diverse community of animals, from tiny invertebrates to large fish, crabs, turtles, marine mammals and birds.

The researchers performed measurements of the ability of seagrass along Mexico’s Yucatan Peninsula coastline to keep sand in place and prevent erosion.  They found that the amount of erosion was strongly linked to the amount of vegetation.  Quite often, seagrass beds have been regarded as a nuisance, rather than a valuable asset for preserving valuable coastlines.  The study opens opportunities for developing new tropical beach protection schemes in which ecology is integrated into engineering solutions.

**********

Web Links

Seagrass Saves Beaches and Money

Photo, posted October 13, 2010, courtesy of NOAA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rapid Response To Climate Change More Important Than Ever

By Leave a Comment

The Intergovernmental Panel on Climate Change has issued a new report emphasizing the importance of taking rapid action to limit global warming to 1.5 degrees Celsius and examining the consequences of allowing temperatures to rise 2 degrees instead.

[Read more…] about Rapid Response To Climate Change More Important Than Ever

Unexpected Effects Of Climate Change

By Leave a Comment

The effects of climate change are discussed all the time.  We hear a lot about rising seas, extreme weather events, and so on.  And mostly, the weather gets warmer.  Heatwaves are increasingly common and longer and stronger.

[Read more…] about Unexpected Effects Of Climate Change

Floating Cities

By Leave a Comment

A familiar theme in science fiction is the idea of floating cities – independent, self-sustaining nation-states at sea where start-up societies work to redesign society and government and don’t have to fight over who owns the land.  The concept even has a name:  seasteading.

[Read more…] about Floating Cities

Cracking In The Antarctic

By

A rapidly-growing crack in the fourth-largest ice shelf in Antarctica has scientists watching for it to break off entirely.  By early February, the crack in the Larsen C ice shelf was more than 100 miles long and some parts of it were 2 miles wide.   In the two-month period between December and February, the crack grew by 17 miles, a pace of about five football fields a day.

[Read more…] about Cracking In The Antarctic

Changing National Parks

By

America’s National Parks are special places of incomparable beauty and fascination.  When the National Park Service was first created 100 years ago, it was instructed to leave these places “unimpaired for the enjoyment of future generations.”   We now live in a time when the changing climate is altering many aspects of the landscape including in many national parks.  The parks are protected, but they are changing.

[Read more…] about Changing National Parks

Hot Times For Santa

By

Santa Claus may have to change out of that heavy red suit this Christmas.  The North Pole, site of his fabled workshop, is seeing historically high temperatures this year.  In fact, it is 36 degrees Fahrenheit higher than it has been in past decades.  This is a staggering number.

[Read more…] about Hot Times For Santa

Ghost Forests

By

Coastal floodplains across the southeastern and mid-Atlantic regions of the United States are at the leading edge of climate change’s effect on what were largely freshwater ecosystems.    Because of the low elevation and flat or gently sloping characteristics of coastal forests in these areas, they are among the most vulnerable globally to saltwater intrusion.

[Read more…] about Ghost Forests

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)