Extra 23 million people could face coastal flooding within 30 years, even with emission cuts

Extra 23 million people could face coastal flooding within 30 years, even with emission cuts

SOURCE: The Guardian DATE: July 30, 2020 SNIP: The combined impacts of human-caused sea level rise, storm surges and high tides could expose an extra 23 million people to coastal flooding within the next 30 years, even with relatively ambitious cuts to greenhouse gas emissions, a new global study has found. In a worst-case scenario where emissions continue to rise and no efforts are made to adapt to the rising sea levels, coastal assets worth US$14.2tn – about 20% of global GDP – could be at risk by the end of the century. Rising sea levels caused by global heating that expands the oceans and melts land-based ice could mean that one-in-100-year floods occurring now would become one-in-10-year floods by the end of the century. As much as 4% of the world’s population could be affected by flooding. The study, published in the journal Scientific Reports, identified “hotspot” regions at risk of extensive flooding. South-eastern China, Australia’s north, Bangladesh, West Bengal and Gujarat in India were especially at risk. In the United States, North Carolina, Virginia and Maryland were considered to be most exposed, as were the UK, northern France and northern Germany. But the study also shows how the risk of damage from rising sea levels and storm surges will continue to rise even if emissions are kept to a level that would keep the global temperature rise to well below 2C by the end of this century. The new study builds on findings published by the United Nations Intergovernmental Panel on Climate Change in 2019 that predicted extreme sea level events could be near annual occurrences by...
Mississippi Delta marshes in a state of irreversible collapse

Mississippi Delta marshes in a state of irreversible collapse

SOURCE: Phys.org DATE: May 22, 2020 SNIP: Given the present-day rate of global sea-level rise, remaining marshes in the Mississippi Delta are likely to drown, according to a new Tulane University study. A key finding of the study, published in Science Advances, is that coastal marshes experience tipping points, where a small increase in the rate of sea-level rise leads to widespread submergence. The loss of 2,000 square miles (5,000 km2) of wetlands in coastal Louisiana over the past century is well documented, but it has been more challenging to predict the fate of the remaining 6,000 square miles (15,000 km2) of marshland. “Previous investigations have suggested that marshes can keep up with rates of sea-level rise as high as half an inch per year (10 mm/yr), but those studies were based on observations over very short time windows, typically a few decades or less,” said Torbjörn Törnqvist, lead author and Vokes Geology Professor in the Tulane Department of Earth and Environmental Sciences. The researchers found that in the Mississippi Delta most marshes drown in a few centuries once the rate of sea-level rise exceeds about one-tenth of an inch per year (3 mm/yr). When the rate exceeds a quarter of an inch per year (7.5 mm/yr), drowning occurs in about half a century. “The scary thing is that the present-day rate of global sea-level rise, due to climate change, has already exceeded the initial tipping point for marsh drowning,” Törnqvist said. “And as things stand right now, the rate of sea-level rise will continue to accelerate and put us on track for marshes to disappear even faster in...
Sea level rise accelerating along US coastline, scientists warn

Sea level rise accelerating along US coastline, scientists warn

SOURCE: The Guardian DATE: February 3, 2020 SNIP: The pace of sea level rise accelerated at nearly all measurement stations along the US coastline in 2019, with scientists warning some of the bleakest scenarios for inundation and flooding are steadily becoming more likely. Of 32 tide-gauge stations in locations along the vast US coastline, 25 showed a clear acceleration in sea level rise last year, according to researchers at the Virginia Institute of Marine Science (VIMS). The selected measurements are from coastal locations spanning from Maine to Alaska. About 40% of the US population lives in or near coastal areas. The gathering speed of sea level rise is evident even within the space of a year, with water levels at the 25 sites rising at a faster rate in 2019 than in 2018. The highest rate of sea level rise was recorded along the Gulf of Mexico shoreline, with Grand Isle, Louisiana, experiencing a 7.93mm annual increase, more than double the global average. The Texas locations of Galveston and Rockport had the next largest sea level rise increases. Generally speaking, the sea level is rising faster on the US east and Gulf coasts compared with the US west coast, partially because land on the eastern seaboard is gradually sinking. Researchers at VIMS said that the current speed-up in sea level rise started around 2013 or 2014 and is probably caused by ocean dynamics and ice sheet loss. Worldwide, sea level rise is being driven by the melting of large glaciers and the thermal expansion of ocean water due to human-induced global heating. The US’s National Oceanic and Atmospheric Administration...
When will the Netherlands disappear?

When will the Netherlands disappear?

SOURCE: Politico DATE: December 16, 2019 SNIP: With unprecedented sea level rise forecast as a result of climate change, the Dutch government is racing against the clock to figure out how to keep one of the world’s richest countries from disappearing into the North Sea. In more optimistic scenarios, the feted Dutch dikes, storm barriers, pumps, and adaptations can cope, but at a cost — and even then only up to a point. “On the other end of the spectrum is controlled abandonment, which isn’t nice, because we somehow need to lead 10 million people somewhere,” said Maarten Kleinhans, professor of geosciences and physical geography at Utrecht University. “And as soon as this gets known, as soon as the shit hits the fan, there won’t be any investments anymore and local economies will collapse.” A certain amount of sea rise is already inevitable, set in motion by global warming and ice melting caused by decades of carbon emissions. The Intergovernmental Panel on Climate Change, the United Nations body that collates and assesses scientific results, predicts 30 to 60 centimeters of sea rise by 2100, even if countries make good on their pledges to cut emissions under the Paris Climate Agreement. The quicker emissions are cut, the lesser the risk of unmanageable rise. But so far, the developed world is failing to meet its targets. If emissions continue on current trends, the IPCC predicts 84 centimeters of sea rise by 2100, and as much as 5.4 meters by 2300. The IPCC has also warned that a rise of more than a meter by 2100 is not unlikely, and advised at-risk...
New projections show that South Florida is in for even more sea level rise

New projections show that South Florida is in for even more sea level rise

SOURCE: Miami Herald DATE: December 4, 2019 SNIP: The timeline for South Florida to prepare for sea level rise just sped up a little. New projections show the region is in for higher seas, faster. The latest predictions aren’t catastrophically different than previous years — unless your yard is already flooding a couple of times a year from the steadily encroaching seas. In that case, a few inches a few years early is pretty important. The sea rise curves unveiled Wednesday at the Southeast Florida Climate Leadership Summit in Key West tack on about three to five extra inches by 2060, and that number only gets bigger in the future. The region went from expecting between 14 and 26 inches of sea level rise by 2060 — commonly shortened to two feet by 2060 by local leaders — to predicting 17 to 31 inches of sea rise. “These numbers are all big enough that you can see that South Florida gets in big trouble quickly,” said Harold Wanless, a University of Miami professor of geology and member of the projections team. “If you look out the window, like the areas in the Keys that are flooding for weeks on end, this is not something that might happen, this is something that is already happening.“ These new numbers come from a group of more than a dozen scientists, researchers and local government staffers from South Florida as an update to 2015...