By Marlene Cimons
Scientists know that sea levels have risen more in some places during the past century than in others. They've gone up faster along the Mid-Atlantic States, particularly near Cape Hatteras and the Chesapeake Bay, compared to north along the Gulf of Maine and south along the South Atlantic Bight. But why?
"Sea-level rise affects us all," said Chris Piecuch, assistant scientist at the Woods Hole Oceanographic Institution and lead author of a new study recently published in the journal Nature that explains the reasons for sea-level rise variations on the East Coast. "Those of us who live on the coast are feeling, and will continue, to feel more acutely its effects. But even those who don't live on the coast will feel the effects. Going into the future, over the coming centuries, multiple meters of global sea-level rise are possible. And even if the nature of storms doesn't change in the future, the higher 'baseline' of rising seas will make the impacts of coastal storms worse. Sea-level rise will come, making the bad worse."
Piecuch and his colleagues attribute the "unequal" sea-level rise in the East to a phenomenon known as "post-glacial rebound."
Thousands of years ago, large ice sheets covered large parts of northern North America, including large swaths of Canada and the northeastern U.S. As a consequence—because the ice sheets were so massive and heavy—they weighed down Earth's crust, causing it to sink directly beneath the ice sheet. "As a result, places that were around the edges or periphery of that ice sheet were actually levered up," Piecuch explained. "It's an imperfect analogy, but you can perhaps think of a see-saw. When you sit on one end of a seesaw, it goes down, whereas the other end of the seesaw goes up. Again, this was the picture thousands of years ago."
In the intervening time, the ice sheets melted, reducing the weight. As a result, the areas formerly sunken down under that massive weight could relax and rise up, whereas those regions around the edges that were formerly levered or bulged up sank, he said. "The seesaw is again helpful here," he said. "If you imagine stepping off the seesaw now, the end you'd been sitting on can rise back up, whereas the other end now sinks down."
Even though the ice sheets had disappeared by 7,000 years ago, the see-sawing of post-glacial rebound continues to this day, he said. "Because the Earth responds so gradually—and is, in a sense, still feeling the last ice age—that 'reverse' see-sawing is still ongoing, with land moving up in some places and down in others," he said. "And it's that spatially variable land motion that gives the effect of different rates of sea-level rise at different places on the East Coast."
While the differences on the East Coast are due mainly to naturally occurring post-glacial rebound, the exacerbating effects of climate change are "felt everywhere along the east coast commonly," he said. "The oceans are warming and expanding thermally, and land ice is melting, and that water is running off into the ocean, both causing sea level to rise. We know that global sea-level rise over the last century was faster than any other time during the last three millennia, that sea levels wouldn't have risen nearly the amount we observe if it weren't for human influence, and we know that—even over just the last 25 years—the rate of global sea-level rise has been accelerating. These and other evidences are telling us that what has been happening during the recent past is unusual and anomalous. And, based on our best understanding of the science, we can only anticipate that things will continue to accelerate, and problems of coastal impacts worsen."
To figure out why sea levels rose faster during the last 100 years in such areas as Norfolk Naval Station in Virginia and the Outer Banks in North Carolina, Piecuch and his team collected tidal gauge measurements of sea levels, GPS satellite data showing the extent of up-and-down land movement over time, and fossils in sediment from salt marshes, a record of past coastal sea levels. They combined this observational data with complex geophysical models—which hasn't been done before, they said—for a more complete interpretation of sea level changes since 1900.
Norfolk, Virginia and the Outer Banks, North Carolina.Google Maps
They found that post-glacial rebound accounted for most of the variation in sea-level rise along the East Coast. But even after eliminating the post-glacial rebound factor, "sea level trends [still] increased steadily from Maine all the way down to Florida," Piecuch said. "The cause for that could involve more recent melting of glaciers and ice sheets, groundwater extraction and damming over the last century.
"Sea level is a complicated problem," he continued. "Lots of processes can lead to sea-level rise, for example, geological processes like post-glacial rebound compounding the problem of climate change and its impacts on the coast. One thing that's useful about our study is that, for the East Coast, we've pinned down one part of the problem. And, since that problem unfolds over very long time scales, we can be confident predicting that component of sea-level rise centuries into the future. But, of course, that says nothing about the other parts of the sea-level rise problem, for example, due to ongoing ice melting and ocean warming."
His study is an attempt to bolster scientific knowledge about the factors involved, which should "help us understand how and why they will rise into the future, at a particular place, and for a particular time horizon," he said. "While these studies can't stem the rise of the tides, it can give us the best information possible so as to help us anticipate the impacts on our coasts."
To be sure, uncertainties remain. "We're still trying to understand just how much and just how fast sea levels will rise in the future," he said. Nevertheless, the news almost certainly will be bad. "There really are no good stories here," he said. "Under no physically plausible scenarios will global sea levels go down. They're certainly going to continue rising, very probably at accelerated rates, for decades and centuries into the future."
Reposted with permission from our media associate Nexus Media.
- Thom Yorke of Radiohead Releases Song With Greenpeace to Help ... ›
- Patti Smith, Thom Yorke, Flea and More Featured on Just Released ... ›
- Musicians and Activists Unite at 'Pathway to Paris' - EcoWatch ›
EcoWatch Daily Newsletter
A national park in Thailand has come up with an innovative way to make sure guests clean up their own trash: mail it back to them.
- Supermarkets in Thailand and Vietnam Swap Plastic Packaging for ... ›
- Malaysia Sends Plastic Waste Back to 13 Wealthy Countries, Says It ... ›
- Thailand Begins the New Year With Plastic Bag Ban - EcoWatch ›
- Coronavirus Worsens Thailand's Plastic Waste Crisis - EcoWatch ›
- Marium, Thailand's Beloved Baby Dugong, Is the Latest Victim of ... ›
By Ilana Cohen
Four years ago, Jacob Abel cast his first presidential vote for Donald Trump. As a young conservative from Concord, North Carolina, the choice felt natural.
But this November, he plans to cast a "protest vote" for a write-in candidate or abstain from casting a ballot for president. A determining factor in his 180-degree turn? Climate change.
Fractures Among Young Climate Conservatives<p>While young conservatives have united around the urgency of climate change, they remain divided over how to bring their concerns to the ballot box. Some embrace right-wing <a href="https://www.washingtonpost.com/politics/biden-attacks-republican-convention/2020/08/24/434e5b46-e66d-11ea-970a-64c73a1c2392_story.html" target="_blank">attacks</a> painting Biden as a "tool of the left" and find his climate agenda "radical." Others can't find a way to justify voting for Trump, even if it means breaking with their party.</p><p>Patrick Mann from Orange County, California, voted for Trump in 2016. But today, he's leading Aggies for Joe at Texas A&M University and is co-founder of Texas Students for Biden. </p><p>Mann grew up watching wildfires ravage his home state, nearly forcing his family to evacuate in 2017. The GOP is failing to "meet the moment" for climate action, Mann said. He's hoping Biden will deliver on a promise to "<a href="https://www.desmoinesregister.com/story/opinion/columnists/caucus/2020/01/06/joe-biden-democrat-president-iowa-caucus-restore-soul-our-nation/2806422001/" target="_blank">restore the soul of our nation</a>." </p><p>Taylor Walker from Pensacola, Florida, is also determined to make her voice heard on climate, including by casting her first-ever vote for president—but not for Biden.</p>
A False Equivalency<p>Young climate conservatives may fear climate denial and delayed climate action, but more than that, they fear the growing political momentum around the Green New Deal, the massive spending it entails and <a href="https://joebiden.com/climate-plan/" target="_blank">Biden's citing of it</a> as a "crucial framing for meeting the climate challenges we face."</p><p>Many don't want to split with their party to support a Democrat whose <a href="https://www.npr.org/2019/09/03/757220130/joe-biden-on-bipartisanship-gun-control-and-regrets-over-inaction-after-a-traged" target="_blank">allegedly bipartisan intentions</a> they doubt. If stymieing what they consider a radical green agenda means re-electing a climate change denying president, so be it. </p><p>"I'm scared of climate change, but I'm also scared of the Green New Deal and what it means for America," said Ben Mutolo, a republicEN spokesperson and junior at SUNY College of Environmental Science and Forestry. </p><p>Mutolo felt encouraged by former Ohio Governor John Kasich's <a href="https://www.rollcall.com/2020/08/17/kasich-speech-to-democratic-convention-follows-years-of-building-conservative-credentials/" target="_blank" rel="noopener noreferrer">appearance</a> at the Democratic National Convention, but he still struggles to see himself voting for Biden. Though the candidate paints himself as a <a href="https://www.latimes.com/politics/story/2020-08-12/harris-biden-different-generation-similar-political-instinct" target="_blank" rel="noopener noreferrer">centrist,</a> Mutolo believes he's "cozying up to the ultra-progressive left." </p><p>Mutolo, who wants to see market-based climate solutions like a carbon tax, feels torn between a candidate whose climate plan relies on taking an "<a href="https://joebiden.com/environmental-justice-plan/#" target="_blank" rel="noopener noreferrer">All-of-Government approach</a>," and one with no efforts to reign in global warming at all. <span></span></p><p>Leiserowitz said he appreciated how a conservative might feel Biden's climate plan "doesn't jive with their limited government, free-market approach."</p><p>But he sees a strong distinction between voting for a presidential candidate with a <a href="https://www.nytimes.com/2020/07/14/us/politics/biden-climate-plan.html" target="_blank">$2 trillion climate plan</a> that includes large renewable energy investments, which have <a href="https://climatecommunication.yale.edu/publications/politics-global-warming-april-2020/" target="_blank" rel="noopener noreferrer">bipartisan support</a>, and a candidate trying "to take the country in the opposite direction, towards more fossil fuels."</p>
- 7 Republicans Joined Senate Democrats in Vote to Fight Climate ... ›
- Climate Change Acknowledged by Increasing Number of ... ›
The World Health Organization (WHO) announced Monday that 64 high-income nations have joined an effort to distribute a COVID-19 vaccine fairly, prioritizing the most vulnerable citizens, as Science reported. The program is called the COVID-19 Vaccines Global Access Facility, or Covax, and it is a joint effort led by the WHO, the Coalition for Epidemic Preparedness Innovations (CEPI) and Gavi, the Vaccine Alliance.
- Trump Denies CDC Director's 2021 Timeline for Coronavirus Vaccine ›
- CDC Tells States to Prepare for a Vaccine Before November Election ›
- Fauci Warns Pre-Pandemic Normalcy Not Likely Until Late 2021 ... ›
By Gloria Oladipo
In the face of dangerous heat waves this summer, Americans have taken shelter in air conditioned cooling centers. Normally, that would be a wise choice, but during a pandemic, indoor shelters present new risks. The same air conditioning systems that keep us cool recirculate air around us, potentially spreading the coronavirus.