sea level rise

RECENT POSTS

July 8, 2011 | 11:19 AM | By

Who’s most vulnerable to climate change? See for yourself.

Center for Global Development

The U.S. ranks 149 out of 169 - pretty low - in terms of overall vulnerability to the combined impacts of extreme weather, sea level rise, and loss of agricultural productivity. Africa and Southeast Asia top the rankings, in large part because of their lack of ability to cope with potential impacts.

Thanks to Humanosphere‘s Tom Paulson for pointing out this interactive map of climate impacts worldwide, produced by the Center for Global Development. While it’s tempting to look at the above map and say “Hey, we’re in pretty good shape,” it might be more accurate to say “Wow, they’re really $#@!-ed.” In other words, just because we rank low on the vulnerability scale, that doesn’t mean we won’t be impacted by climate change. It just means that impacts will be even more severe elsewhere, and that we have more means to cope with the impacts.

Extreme weather is one possible exception to our apparent invincibility, and a stark example of the benefits of living in the wealthiest nation on Earth. The Center for Global Development actually ranks the U.S. as the 25th most impacted country when it comes to extreme weather (FYI, China takes the top spot). In contrast, while our vulnerability ranking is still firmly in the top half, we drop to 63rd place because of our capacity for handling the impacts of extreme weather events.

FILED UNDER: Human Impacts, extreme weather, sea level rise, see for yourself
July 6, 2011 | 2:44 PM | By

The long history of erosion and science in the National Seashore

Heather Goldstone / WCAI

Erosion is eating away at a decades-old roadway turned seawall at Herring Cove Beach in Provincetown, MA.

Speaking of shifting baselines, Rich Eldred recently had a great piece in the Cape Codder about the long history of coastal erosion – and the study of it – along Cape Cod’s National Seashore.

 

Mark Adams, GIS (geological information system) specialist at the Seashore, has taken advantage of the work of one of his predecessors, Henry Marindin, who surveyed the boundaries of the shoreline in 1888.

“That results in a 120-year-scale record of coastal change for the ocean side of Cape Cod,” Adams says. “Year-to-year changes on the coast have been going on for approximately 12,000 years since the glaciers receded. It’s highly variable, so any given year, say at Longnook in Truro or Highland Light, the bluff could erode by inches or by 20 feet.”

There were no coastal geologists 12,000 years ago to monitor shoreline change, nor any newspapers to inform the public about them. But Henry Marindin worked for the U.S. Coast and Geodetic Survey and he measured the bluffs and beaches from 1887 to 1889, creating 229 coastal profiles, at 300-meter intervals, from Provincetown to Chatham. His records extended out to sea for one to two kilometers.

“He was far-sighted enough to do the survey with us in mind, thinking someone would come along and redo these to a 100-year perspective,” Adams says. “That would weed out the year-to-year variation to see what the real erosion rate is. He got the elevations on land and the depths in the water.”

Continue reading →

FILED UNDER: Ocean Change, Cape Cod National Seashore, coastal change, sea level rise
June 28, 2011 | 9:57 PM | By

Is climate change causing sea level rise?

Salt marshes, beaches, and coastal development face the threat of accelerating sea level rise. Marshes can also help scientists uncover past sea level changes.

A new study – published in a high-profile scientific journal with an author list that reads like a who’s who of ocean and climate science – finds that sea level is rising faster than at any point in the past two thousand years and human-caused global warming is to blame.

If you’ve been following the sea level rise story closely, that kind of declaration may prompt a weary “Another one?” Virtually every new scientific study or academic review released in the past year has concluded that the rate of sea level rise is accelerating toward the unprecedented thanks to rising water temperatures and ever more rapidly melting glaciers. As a result, middle-of-the-road estimates of sea level rise for the coming century have increased from a foot or more (just a few years ago) to at least three feet.

Nonetheless, a new sea level rise study published last week caused quite a ruckus, both in the media and among academics. At the heart of both the media frenzy and the scientific debate is the claim that the new data clearly links current – unprecedented – sea level rise to climate change. It’s hard to argue that rising air and water temperatures won’t raise sea level. That’s basic physics – warmer water expands, and rising air and water temperatures drive melting of ice that adds water to the oceans. What’s at issue is essentially the question of how much sea level rise can be attributed to human greenhouse gas emissions.

Continue reading →

FILED UNDER: Ocean Change, sea level rise
June 28, 2011 | 9:58 AM | By

EPA recommends retreat from rising seas

flickr/hollyladd

Moving homes impacted by erosion - like this one on Smith's Point, Nantucket Island - could be part of a strategy of retreat from rising sea level.

From the Cape Cod Canal and New Bedford’s hurricane barrier, to the levees of the Mississippi River, the Army Corps of Engineers has shaped the very landscape of the United States. But many of the Corps’ greatest feats of engineering are coming to be seen as naive, foolhardy, even misinformed attempts to master nature. When it comes to rising sea level, Darryl Fears (Washington Post) reports that the Army Corps’ way may be the way of the past.

… in the past, municipalities turned to a manual published by the Army Corps of Engineers since 1954 on how to protect shores by holding back the sea.

But earlier this month, the U.S. Environmental Protection Agency published the first manual on how not to hold it back, arguing that costly seawalls and dikes eventually fail because sea-level rise is unstoppable.

So what does the EPA suggest instead?

Continue reading →

FILED UNDER: Adaptation, coastal change, sea level rise
June 9, 2011 | 1:08 PM | By

Is New Bedford’s hurricane barrier the future of Cape Cod?

southcoasttoday.com

The hurricane barrier that protects New Bedford Harbor has been cleared for federal recertification.

Earlier this week, the New Bedford Standard Times reported that the hurricane barrier that spans the mouth of New Bedford Harbor has passed a federal inspection and is ready for re-certification. Why is that news?

A few fun facts:
  • The wall connects the cities of New Bedford and Fairhaven.
  • At 3.5 miles in length, it is the largest stone structure on the East Coast and the largest hurricane barrier in the world.
  • There is one navigational gate that spans a 150-foot-wide gap. The gate doors weigh 400 tons each and take about 12 minutes to close.
  • The barrier was constructed by the Army Corps of Engineers in 1966 to prevent a repeat of the damage from big hurricanes in 1938, 1944 and 1954.
  • It took four years to build and cost $18 million dollars. The rocks cost the government 5 cents per pound.
  • Maintenance of the barrier costs the city of New Bedford about $50,000 to $60,000
  • It’s not a solid rock wall: there’s a tunnel inside. Take a look:

The barrier protects about 1,400 acres of heavily developed industrial and commercial property – the Whaling City’s working waterfront – and the fishing fleet that consistently makes New Bedford the highest grossing fishing port in the country.

NOAA forecasters are calling for an active hurricane season, so the fact that the barrier is up to snuff is certainly good news. But the re-certification also means that the wall can be included in the Federal Emergency Management Agency’s revisions of flood maps; even as sea level rises, the flood vulnerability of the protected area behind it will remain unchanged.

Continue reading →

FILED UNDER: Adaptation, coastal change, geoengineering, hurricanes, sea level rise
June 6, 2011 | 10:12 AM | By

How local landmarks show us coastal change

Courtesy of Sam Low

The end of Little Bridge re-emerges from the sand in Harthaven, Martha's Vineyard.

A report released by the U.S. Geological Survey in February concluded that 68% of beaches in the New England and Mid-Atlantic regions are eroding. Coastal development, storm activity, and rising sea levels are top culprits.

Storm damage can be dramatic, rearranging coastlines, creating new inlets and closing off others, all in the span of a few days. The impacts of sea level rise and coastal armoring (sea walls, jetties, and other hard structures that can disrupt the natural flow of sand and sediment along the coast) manifest at a slower pace. Still, with several inches of sea level rise in the past fifty years and extensive coastal armoring in the early- to mid-1900′s, the changes can be seen clearly in a human lifetime.

Local landmarks can be lost to shifting sands and sometimes revealed again. The Marconi radio towers on the National Seashore are one example I’ve mentioned before. Little Bridge in Harthaven, on Martha’s Vineyard, is perhaps less widely known than the historic Marconi radio towers but its fate serves to make the same point. Sam Low – a photographer, filmmaker, and writer living on the Vineyard – recently sent me this brief reminiscence, originally published in the Martha’s Vineyard Gazette:

“I remember jumping off the old little wooden bridge that used to cross over to get to the beach by Young’s old house. Also digging the best steamers in that little water way.” Polly Pease.

Courtesy of Sam Low

Among the most vivid memories of Harthaven folks who were children in the fifties and sixties is swimming in the channel between the “Youngʼs house” off Seaview Avenue and the beach. It was all that remained of a much larger waterway that once connected the “old jetties” to the harbor. In the 30s and 40s, the channel had been deep enough to allow the passage of goodly sized yachts. By the 50s it had closed in a lot, so parents could allow young children to swim there safely because it was so shallow. A small wooden bridge allowed bathers to cross over the channel and go on to the beach about 100 – 150 feet beyond. Over the years, the channel silted in and the beach eroded and the bridge disappeared under the sand. A short while back, Jed Conlin was walking the beach and discovered the end of the bridge re-emerging, so I went down to take its picture.

This is pretty dramatic testimony to the erosion rate in the Harthaven area. Letʼs say that in the 50s there was 100 feet of beach from the end of the bridge where it crossed the channel to the edge of the ocean. Now the bridge is almost in the ocean. If my math is any good, that means we have lost more than a foot and a half of shoreline every year for the last sixty-one years.

Sam’s math is spot on, by the way. The same U.S. Geological Survey report that found 68% of beaches were eroding also found that the average rate of beach loss was 1.6 feet per year. In the most extreme cases, that number can be more than 60 feet per year.

FILED UNDER: Ocean Change, coastal change, sea level rise
May 12, 2011 | 11:15 AM | By

Linking ocean and ice to understand sea level rise

This morning I had the pleasure of guest hosting The Point on WCAI. I interviewed Woods Hole Oceanographic Institution’s Dr. Fiamma Straneo about her research on Greenland’s glaciers. I’ll have the audio of that interview to post in the near future. In the meantime …

Massive sheets of ice cover four fifths of Greenland, an area a third the size of the United States. If those glaciers were to melt completely, it could raise sea level by more than 20 feet. That’s not expected to happen anytime soon, but Greenland’s glaciers have been melting more and more quickly in recent years – more quickly than scientists could explain based on rising air temperatures. Fiamma has been exploring how rising ocean temperatures and changing circulation patterns contribute to the melting of Greenland’s glaciers.

Fiamma has used helicopters, small fishing boats, a Greenpeace icebreaker – anything she can get her hands on – to get herself and her instruments to the ocean edge of Greenland’s glaciers. She was part of the first team of scientists to survey wintertime conditions at the edge of the ice sheets. Her daring and groundbreaking research has made headlines in the past year.

NY Times – Justin Gillis: An extensive review of what we do and don’t know about glacial melting and sea level rise.

Live Science – Lynn Peeples: Includes some great photo series showing the retreat of Helheim glacier in Greenland.

Oceanus – Cherie Winner: In-depth story about Fiamma’s research and the basics of glacial melting.

FILED UNDER: Ocean Change, sea level rise, Woods Hole Oceanographic Institution
May 5, 2011 | 1:36 PM | By

Everything I need to know about sea level rise I learned on vacation

Heather Goldstone

I have to thank all of you still here for indulging my extended absence. In today’s non-stop, ’round-the-clock media onslaught, ten days is a long vacation for a blogger. But all that fun in the sun served a purpose. My two young boys had a chance to get reacquainted with their grandparents after a nineteen month hiatus, otherwise known as the final leg of my parents’ circumnavigation. And I got to watch sea level rise in action.

Okay, not literally. What I was really watching was the rise and fall of the tides – in essence, a foot of sea level rise happening twice each day – and its impact on a child’s beach constructions.

Each day, my four-year-old (usually with the help of my forty-year-old) would spend hours crafting islands, forts, canals, and harbors along the ocean’s edge. As the tide would rise, they’d furiously add sand and rocks before eventually retreating up the shore to start anew. And each morning, my son would anxiously rush down to the beach to see whether their latest and greatest schemes had lasted the night. The answer was always the same: no.

After a few days (I’m a little slow on the uptake sometimes), the parallels to the conundrum we face with coastal development and sea level rise became obvious. As I’ve said before, we basically have three options for coping with rising sea levels, and none of them is perfect:

  1. Armor the coast: Sea walls can protect homes and roads behind them, but they take a heavy toll on neighboring beaches and marshes by stopping the natural flow of sand along the coast. They’re also expensive to build, maintain, and upgrade to keep pace with rising sea levels and increasingly extreme weather.
  2. Nourish beaches: Adding sand, planting dune grasses, even reinforcing dunes with degradable skeletons, are all ways to help maintain beaches and dunes that naturally protect what’s behind them. But again, it’s a temporary and expensive solution.
  3. Retreat: Abandoning or moving coastal development eliminates the conflict and allows coastlines to move naturally, but is economically and emotionally fraught.

The daily struggles of my four-year-old highlighted the pitfalls of all three strategies. Within the space of a day, sandcastles piled high with sand and painstakingly reinforced with rocks were reduced to nothing more than piles of rubble. At the end of a week, what was left resembled a sunken island chain.

The week also provided a glimpse into the human psyche. At first, each loss was met with disappointment, dismay, and desperation. But by week’s end, my son glibly accepted the fate of his creations and greeted the daily challenge of rebuilding with a degree of gusto.

Did the solution to all our problems reveal itself during my idyllic week on the beach? Of course not. After all, sandcastles are a far cry from cherished family homes and critical infrastructure. And experts have told me that there is no silver bullet; that adapting to rising sea levels will require a host of strategies, and likely some major attitude adjustments. But, as is often the case, watching my son come to grips with the realities of his world gave me hope and a renewed confidence in human resilience and creativity.

FILED UNDER: Adaptation, sea level rise
May 4, 2011 | 2:03 PM | By

Caribbean islands fear climate change impacts on tourism

Heather Goldstone

Having just arrived back from a Caribbean island, this resonated:

Linda Hutchinson-Jafar reports for Reuters that business owners and government officials in the world’s most tourism-dependent region fear climate change threatens their lifeblood.

Regina Dumas, who runs the Coffee River Resort on the cigar-shaped Caribbean island of Tobago, worries that local tourism is suffering from increasingly uncertain weather.

“Last year’s dry season was excessively dry, and this year we’ve had excessive rain,” she says. “When people spend their money to come to the island, they’re disappointed with the erratic weather we’ve been experiencing. It’s just unpredictable.”

Orville London, chief secretary of the Tobago House of Assembly, also says he sees changes indicative of climate change.

“We can no longer be considered to be outside of the hurricane belt,” he explains. “Once there was the perception that we were almost immune from hurricanes, but recent changes have indicated that this is not necessarily the case based on the kind of natural challenges we’ve had in recent years.”

Besides more extreme weather patterns, London notes that other impacts linked with climate change, such as coastal erosion and coral bleaching, are starting to be felt locally. Studies are being carried out to determine how best the island can prepare itself for global warming.

Experts and government officials agree that climate change impacts – from damaged reefs, to reduced biodiversity on land, and more erratic weather – need to be at the forefront in planning for future tourism. But a recent report from the International Institute of Environment and Development says tourism in the region faces an additional threat:

Overseas tourists could be put off due to growing awareness of the carbon emitted by  long-haul flights or by environmental taxes on  aviation, such as that imposed on travel from Britain. That could make Caribbean destinations less attractive for European visitors.

Of course, an island doesn’t have to be Caribbean, or even tropical, to depend on tourism and be impacted by climate change. Wink, wink, nudge, nudge.

FILED UNDER: Human Impacts, sea level rise