New Figures: More of U.S. at Risk to Sea Level Rise

Washington D.C. - Nearly 4 million people across the United States, from Los Angeles to much of the East Coast, live in homes more prone to flooding from rising seas fueled by global warming, according to a new method of looking at flood risk published in two scientific papers.

The cities that have the most people living within three feet (one meter) of high tide — the projected sea level rise by the year 2100 made by many scientists and computer models — are in Florida, Louisiana, and New York. New York City, often not thought of as a city prone to flooding, has 141,000 people at risk, which is second only to New Orleans' 284,000. The two big Southeast Florida counties, Miami-Dade and Broward, have 312,000 people at risk combined.

All told, 3.7 million people live in homes within three feet of high tide. More than 500 US cities have at least 10 percent of the population at increased risk, the studies said.

"Southeast Florida is definitely the highest density of population that's really on low coastal land that's really most at risk," said lead author Ben Strauss, a scientist at Climate Central. Climate Central is a New Jersey-based group of scientists and journalists who do research about climate change.

The studies look at people who live in homes within three feet of high tide, whereas old studies looked just at elevation above sea level, according to work published Thursday in the peer-reviewed journal Environmental Research and an accompanying report by Climate Central. That's an important distinction because using high tide is more accurate for flooding impacts, said study co-author Jonathan Overpeck, a scientist at the University of Arizona's Institute of the Environment. And when the new way of looking at risk is factored in, the outlook looks worse, Overpeck said.

"It's shocking to see how large the impacts could be, particularly in southern Florida and Louisiana, but much of the coastal U.S. will share in the serious pain," Overpeck said.

And it's not just residents of coastal areas who will be hurt by this, said Sharlene Leurig, a senior manager for the insurance program at Ceres, a Boston-based investment network. Most coastal areas get flood insurance from the federal program and with more flooding, the program will have to spend more and that will come out of all taxpayers' wallets, she said.

Sea level has already risen about 8 inches since 1880 because warmer waters expand, Strauss said. In addition to the basic physics of ever-warming water expanding, scientist say hotter climate will cause some melting of glaciers in Greenland and western Antarctica that would then cause seas to rise even more.

Flooding from Hurricane Irene last year illustrated how vulnerable coastal places such as Manhattan are with a combination of storms and sea level rise, Strauss said.

Using data from the latest census, Climate Central also has developed an interactive system that allows people to check their risk by entering a ZIP code.

Sea level rise experts at the U.S. Geological Survey and the National Oceanic Atmospheric Administration who weren't part of the studies said the results make sense and were done by experts in the field.

"All low elevation places in the many urban areas along the coast will become more vulnerable," said S. Jeffress Williams, scientist emeritus for the USGS, who wasn't part of the studies. He pointed to Boston, New York City, Norfolk, Va., New Orleans, Charleston, S.C., Miami and Washington and its Virginia suburbs. "More people and infrastructure will be at increasing risk of flooding."

Alien Invasion a Threat to Antarctic Ecosystem

By Pauline Askin

Antarctica - In the pristine frozen continent of Antarctica scientists fear an alien invasion -- not from outer space, but carried in people's pockets and bags.


Seeds and plants accidentally brought to Antarctica by tourists and scientists may introduce alien plant species which could threaten the survival of native plants in the finely balanced ecosystem.


Invasive alien plants are amongst the most significant conservation threat to Antarctica, especially as climate change warms the ice continent, said a report in the Proceedings of the National Academy of Sciences Journal published on Tuesday.


More than 33,000 tourists and 7,000 scientists visit Antarctica each year by ship and aircraft, and a two month survey of visitors has found that many are carrying plant seeds picked up from other countries they have already visited.


The study vacuumed travelers' pockets, trouser and sleeve cuffs, shoes and inside their bags, and used tweezers to pry out accidentally hidden seeds. On average each person checked had just 9.5 seeds in clothing and equipment.


"The people that were carrying the most had lots and lots of seeds. They really were substantial threats," said Dana Bergstrom, from the Australian Antarctic Division.


"When we take things in through hitchhiking then we get species which are competitive. The plants and animals there are not necessarily competitive, so there's a good chance... we'd start losing various precious biodiversity on the (Antarctic) continent," Bergstrom told Reuters.


Amongst the alien species discovered were the Iceland Poppy, Tall Fescue Velvet grass and Annual Winter Grass -- all from cold climates and capable of growing in Antarctica.


The Antarctic Peninsula, where most tourists travel, is now considered a "hot spot" on the frozen continent and the warmer the climate, the easier for seeds to propagate.


"The peninsula is warming at some of the greatest rates on the planet," said Bergstrom.


The study, the first continent-wide assessment of invasive species in Antarctica, surveyed about 1,000 passengers during 2007-2008, the first year of the International Polar Year, an international effort to research the polar regions.


It has taken almost three years to identify the seed species and their effects on the icy continent.

Bergstrom said the one alien seed that had gained a foothold is Annual Winter Grass. It is a substantial weed in the sub-Antarctic and is on the Antarctic island of King George. It has also made its way to the tail part of the Antarctic continent.


"That's just one example of the weeds we picked up and a population of it has just been found in the last couple of seasons," she said.


Annual Winter Grass grows very well in disturbed areas like seal and penguin areas, and could propagate amongst the slow growing mosses around those colonies.


"If it got into those areas in the peninsula it would have the potential to overrun things," Bergstrom said.

Scientists Melt Mystery Over Icecaps and Sea Levels

By David Fogarty

Worldwide - U.S. scientists using satellite data have established a more accurate figure of the amount of annual sea level rise from melting glaciers and ice caps which should aid studies on how quickly coastal areas may flood as global warming gathers pace.

John Wahr of the University of Colorado in Boulder and colleagues, in a study published on Thursday, found that thinning glaciers and icecaps were pushing up sea levels by 1.5 millimeters (0.06 inches) a year, in line with a 1.2 to 1.8 mm range from other studies, some of which forecast sea levels could rise as much as 2 meters (2.2 yards) by 2100.

Sea levels have already risen on average about 18 centimeters since 1900 and rapid global warming will accelerate the pace of the increase, scientists say, threatening coastlines from Vietnam to Florida and forcing low-lying megacities to build costly sea defenses.

To get a better picture of the pace of the melting, Wahr and colleagues used a satellite that measures variations in gravity fields to study changes in the mass of large ice-covered areas. The data covered 2003-2010.

The glaciers and ice caps included those in the Arctic, South America, Asia as well as Greenland and Antarctica.

Globally, the rate of sea level rise has accelerated in recent decades to reach about 3.5 millimeters a year, with more than half coming from thermal expansion of the oceans.

Water expands as it gets warmer.

While the creeping annual increase might seem small, the rate of sea level rise is expected to grow. Yet scientists have struggled to refine estimates given the uncertainty about the future pace of global warming, growth trajectory of greenhouse gas emissions and the rate at which ice caps will melt.
Using satellite data instead of more limited and time-consuming data from ground measurements was crucial, Wahr said in an email to Reuters.

The team found that loss ice from Greenland and Antarctica was pushing up sea levels by just over one millimeter a year, comprising most of the 1.5 mm annual rise.

Glaciers and mountain ice caps elsewhere comprised the rest, at 0.4 mm/yr between 2003-10.

"That's a large number, and represents a lot of melting ice," said Wahr. "But it's at least 30 percent smaller than previous global estimates, none of which have used GRACE," he said, referring to the name of the satellite.

 FASTER MELTING

The United Nations' Climate Panel estimates sea global sea level rise of 18 to 59 centimeters from 1990 to the 2090s. But those numbers do not include melting from polar regions where the vast majority of the world's freshwater is locked away.

Some climate scientists say the rise is more likely to be between and 1 and 2 meters. They point to accelerating melting of the Greenland and West Antarctic icesheets over the past two decades. Both contain enough water to raise global sea levels by about 60 meters.

Other glaciers and mountain icecaps contain enough water to raise sea levels by nearly a meter.
GRACE measured the changes to ice mass over regions greater than 100 square kilometers. The data showed ice-covered areas in Asia, including the Himalayan and Karakoram ranges, was much less than other estimates, meaning the region contributed very little to sea level rise, in part because many glaciers were at freezing high elevations.

Wahr said the study gave a much clearer picture of what was happening to large ice-covered areas globally, particularly in remote parts of the Himalayas.

"There are simply too many glaciers, and most of them too remote to access, to be able to monitor all of them from the ground. There are more than 200,000 glaciers world-wide," he said, adding only a few hundred have been monitored over time spans of several years or more.

"With GRACE, though, we're able to directly monitor the sum total of all ice loss in an entire glacier system or ice cap."

Ongoing monitoring by the satellite should help scientists get a better handle on the pace of ice melting and sea level rise as the planet heats up.

According to the National Oceanic and Atmospheric Administration, all 11 years in the 21st century so far, including 2011, rank among the 13 warmest in the 132-year temperature record.

Scott's Lost Antarctica Photographs Bought

By Maev Kennedy

The last photographs taken by Captain Robert Scott, lost for most of the 20th century, have been bought for the nation in time for the centenary of his doomed expedition to reach the south pole on 17 January 1912.The anniversary is being marked by many institutions, including:

• The Natural History Museum in London, where an exhibition on the venture featuring a recreation of Scott's hut which survives in Antarctica, opens on Friday.
• A conference at the Scott Polar Research Institute in Cambridge, where there is an exhibition with many surviving artefacts.
• The Historic Dockyard at Portsmouth, where a single white rose will be laid at the foot of his statue – sculpted by his widow, Kathleen, and commissioned and paid for by the officers of HMS Vernon in 1915.
• And the British Services Antarctic Expedition in Antarctica, which is currently hauling scientific equipment across the ice on a research and exploration expedition.

The Scott Institute was founded with money left over from the fund for the widows and orphans of Scott and his four companions, who starved and froze to death with him on their heartbreaking return after learning that the Norwegian explorer Roald Amundsen had beaten them to the pole. It has bought the 109 photographs, never seen by Scott himself – they were developed after he set out on the last fatal stage – for about £750,000 with a grant from the Heritage Lottery Fund of £704,000. They will be reunited with Scott's camera, presented by his daughter-in-law Lady Philippa Scott, in 2008. Professor Julian Dowdeswell, head of the Scott Polar Research Institute, said: "Scott's photographs bring to life, in vivid detail, his party's sledging journey into the interior of Antarctica. From men and ponies struggling through deep snow, to panoramas of the Transantarctic mountains, the images are very powerful."

In 2004 the institute acquired the 1,700 glass-plate negatives taken by the expedition photographer, Herbert Ponting.

Scott had asked him for photography lessons because Ponting was not fit enough and his equipment too heavy to cover the final part of the journey. Scott's photographs were developed by the geologist Frank Debenham, who founded the institute.

The photographs were returned to the UK with Ponting's, and kept out of the public gaze by a copyright row. The nitrate film disintegrated, but a single set of surviving prints was mislaid in a photography archive after his death.

When they eventually resurfaced, they were bought at an auction in New York in 2001 by a London-based American antiquarian book dealer, Richard Kossow. He was surprised to be able to afford them, he told the Guardian when they were first published in October. "Most collectors didn't know about the sale, and those who did didn't take it seriously," he said.