As sea levels rise, coastal communities could lose up to 50 percent more of their fresh water supplies than previously thought, according to a new study from Ohio State University.
Hydrologists here have simulated how saltwater will intrude into fresh water aquifers, given the sea level rise predicted by the Intergovernmental Panel on Climate Change (IPCC). The IPCC has concluded that within the next 100 years, sea level could rise as much as 23 inches, flooding coasts worldwide.
Scientists previously assumed that, as saltwater moved inland, it would penetrate underground only as far as it did above ground.
But this new research shows that when saltwater and fresh water meet, they mix in complex ways, depending on the texture of the sand along the coastline. In some cases, a zone of mixed, or brackish, water can extend 50 percent further inland underground than it does above ground.
Like saltwater, brackish water is not safe to drink because it causes dehydration. Water that contains less than 250 milligrams of salt per liter is considered fresh water and safe to drink.
Global warming could cut a swathe through the planet's species over the coming centuries, warns a study released Wednesday that shows a link between rising temperatures and mass extinctions reaching back half a billion years.
Each of five major eras of declining biodiversity -- including one in which 95 percent of the Earth's species disappeared -- correspond to cycles of severe warming over the 520-million-year period for which there are fossil records.
If emissions of greenhouse gas rise unchecked, the predicted increase in global temperature over the next several hundred years could fall within a similar range as these peaks, said the study, published in a British journal, Proceedings of The Royal Society B.
Previous studies have either looked for patterns in climate change or the causes of particular mass extinctions . But this is the first time the two been paired together to give a perspective over such a long time.
"If our results hold for current warming -- the magnitude of which is comparable with the long-term fluctuations in Earth climate -- they suggest that extinctions will increase ," lead author Peter Mayhew said in a statement.
ONE WORLD: The Earth cannot support the demands humanity is placing on it, according to the United Nations Environmental Program.
Since 1987 annual emissions of carbon dioxide—the leading greenhouse gas warming the globe—have risen by a third, global fishing yields have declined by 10.6 million metric tons and the amount of land required to sustain humanity has swelled to more than 54 acres (22 hectares) per person. Yet, Earth can provide only roughly 39 acres (15 hectares) for every person living today, according to the United Nation's Environmental Program's (UNEP) Global Environment Outlook, released this week. "There are no major issues," the report's authors write of the period since their first report in 1987, "for which the foreseeable trends are favorable."
Despite some successes—such as the Montreal Protocol's 95 percent reduction in chemicals that damage the atmosphere's ozone layer and a rise in protected reserves of habitat to cover 12 percent of the planet—humanity's impact continues to grow. For example:
Biodiversity—The planet is in the grips of the sixth great extinction in its 4.5-billion-year history, this one largely man-made. Species are becoming extinct 100 times faster than the average rate in the fossil record. More than 30 percent of amphibians, 12 percent of birds and 23 percent of our own class, mammals, are threatened.
Climate—Average temperatures have climbed 1.4 degrees Fahrenheit (0.76 degree Celsius) over the past century and could increase as much as 8.1 degrees F (4.5 degrees C) over the next unless "drastic" steps are taken to reduce greenhouse gas emissions from, primarily, burning fossil fuels. Developed countries will need to reduce this globe-warming pollution by 60 to 80 percent by mid-century to stave off dire consequences, the report warns. "Fundamental changes in social and economic structures, including lifestyle changes, are crucial if rapid progress is to be achieved."
Food—The amount of food grown per acre has reached one metric ton, but such increasing intensity is also driving rapid desertification of formerly arable land as well as reliance on chemical pesticides and fertilizers. In fact, four billion out of the world's 6.5 billion people could not get enough food to eat without such fertilization. Continuing population growth paired with a shift toward eating more meat leads the UNEP to predict that food demand may more than triple.
Water—One in 10 of the world's major rivers, including the Colorado and the Rio Grande in the U.S., fail to reach the sea for at least part of the year, due to demand for water. And that demand is rising; by 2025, the report predicts, demand for fresh water will rise by 50 percent in the developing world and 18 percent in industrialized countries. At the same time, human activity is polluting existing fresh waters with everything from fertilizer runoff to pharmaceuticals and climate change is shrinking the glaciers that provide drinking water for nearly one third of humanity. "The escalating burden of water demand," the report says, "will become intolerable in water-scarce countries."
Each person requires a third more land for his or her needs than the planet can supply, says the study. Photograph: Corbis
The future of humanity has been put at risk by a failure to address environmental problems including climate change, species extinction and a growing human population, according to a new UN report.
In a sweeping audit of the world's environmental wellbeing, the study by the UN Environment Programme (UNEP) warns that governments are still failing to recognise the seriousness of major environmental issues.
The study, involving more than 1,400 scientists, found that human consumption had far outstripped available resources. Each person on Earth now requires a third more land to supply his or her needs than the planet can supply, it finds.
Meanwhile, biodiversity is seriously threatened by the impact of human activities: 30% of amphibians, 23% of mammals and 12% of birds are under threat of extinction, while one in 10 of the world's large rivers runs dry every year before it reaches the sea.
An epic drought in Georgia threatens the water supply for millions. Florida doesn't have nearly enough water for its expected population boom. The Great Lakes are shrinking. Upstate New York's reservoirs have dropped to record lows. And in the West, the Sierra Nevada snowpack is melting faster each year.
Across America, the picture is critically clear - the nation's freshwater supplies can no longer quench its thirst.
The government projects that at least 36 states will face water shortages within five years because of a combination of rising temperatures, drought, population growth, urban sprawl, waste and excess.
The speed at which mankind has used the Earth’s resources over the past 20 years has put “humanity’s very survival” at risk, a study involving 1,400 scientists has concluded.
The environmental audit, for the United Nations, found that each person in the world now requires a third more land to supply his or her needs than the Earth can supply.
Thirty per cent of amphibians, 23 per cent of mammals and 12 per cent of birds are under threat of extinction, while one in ten of the world’s major rivers runs dry every year before it reaches the sea.
The bleak verdict on the environment was issued as an “urgent call for action” by the United Nations Environment Programme, which said that the “point of no return” was fast approaching.
The report was drafted and researched by almost 400 scientists, all experts in their fields, whose findings were subjected to review by another 1,000 of their peers.
Scientists conducting the review, 157 of whom were nominated by 48 governments, were split into groups of expertise for each of the ten chapters of the report. Other experts were selected from more than 50 research centres in 47 countries.
Marion Cheatle, of the programme, said that damage sustained to the environment was of fundamental economic concern, and if unchecked would affect growth. The report assessed the impact on the environment since 1987.
Climate change was identified as one of the most pressing problems but the condition of fresh water supplies, agricultural land and biodiversity were considered to be of equal concern.
Rising global temperatures caused by climate change could trigger a huge extinction of plants and animals, according to a study. Though humans would probably survive such an event, half of the world's species could be wiped out.
Scientists at the University of York and the University of Leeds examined the relationship between climate and biodiversity over the past 520m years - almost the entire fossil record - and uncovered an association between the two for the first time. When the Earth's temperatures are in a "greenhouse" climate phase, they found that extinctions rates were relatively high. Conversely, during cooler "icehouse" conditions, biodiversity increased.
Dr Mayhew found that of the five mass extinction events in the Earth's history, four were linked to greenhouse climates where the Earth was covered in heat-trapping carbon dioxide or methane gases. This includes the extinction of the dinosaurs 65m years ago , thought to have been caused by the impact of a large asteroid on the Yucatan peninsula and beneath the Gulf of Mexico.
The largest ever extinction occurred 251m years ago, when 95% of animal and plant species were killed off.
The catastrophic fires that are sweeping Southern California are consistent with what climate change models have been predicting for years, experts say, and they may be just a prelude to many more such events in the future -- as vegetation grows heavier than usual and then ignites during prolonged drought periods.
"This is exactly what we've been projecting to happen, both in short-term fire forecasts for this year and the longer term patterns that can be linked to global climate change," said Ronald Neilson, a professor at Oregon State University and bioclimatologist with the USDA Forest Service.
"You can't look at one event such as this and say with certainty that it was caused by a changing climate," said Neilson, who was also a contributor to publications of the Intergovernmental Panel on Climate Change, a co-recipient earlier this month of the 2007 Nobel Peace Prize.
"But things just like this are consistent with what the latest modeling shows," Neilson said, "and may be another piece of evidence that climate change is a reality, one with serious effects."
At Bangkok's watery gates, Buddhist monks cling to a shrinking spit of land around their temple as they wage war against the relentlessly rising sea. Jutting above the water line just ahead in the Gulf of Thailand are remnants of a village that has already slipped beneath the sea.
Experts say these waters, aided by sinking land, threaten to submerge Thailand's sprawling capital of more than 7 million people within this century. Bangkok is one of many of the world's largest cities at risk of being swamped as sea levels rise in coming decades, according to warnings at the recent Intergovernmental Panel on Climate Change held here.
By studying 120,000-year-old layers in the ice of Greenland, researchers have determined that the ice cover seems to be able to survive a warmer climate better than was previously believed. But at the same time they have found signs that the changes that are nevertheless happening will occur at an unexpectedly rapid rate. The level of the global seas may therefore rise faster than was previously thought.
One example of rapid change was found by scientists who were studying a so-called ice stream, ice that moves like a river through the rest of the inland ice and often forms icebergs at the mouth, so-called calving.
“In just two-three years the speed of a large ice stream nearly doubled. This means that we have underestimated the rapid changes that may ensue from the amounts of ice leaving the ice each year,” says Dorthe Dahl-Jensen, a professor at the Niels Bohr Institute at Copenhagen University. Dorthe Dahl-Jensen is taking part in the climate conference “Global Environmental Change: The Role of the Arctic”, arranged by the European Science Foundation, the Swedish Research Council, and the Research Council Formas (Sweden).
The world's oceans appear to be soaking up less carbon dioxide, new environmental research has shown, a development that could speed up global warming.
A 10-year study by researchers from the University of East Anglia has shown that the uptake of CO2 by the North Atlantic ocean halved between the mid-1990s and 2002-2005.
"Such large changes are a tremendous surprise," said Dr Ute Schuster, who will publish the findings with professor Andrew Watson in the Journal of Geophysical Research next month.
"We expected that the uptake would change only slowly because of the ocean's great mass."
There is also evidence of a slowdown in the uptake of CO2 by the Southern ocean, although it is not as great or as sudden as in the North Atlantic.
Cities around the world are facing the danger of rising seas and other disasters related to climate change.
Of the 33 cities predicted to have at least 8 million people by 2015, at least 21 are highly vulnerable, says the Worldwatch Institute.
They include Dhaka in Bangladesh; Buenos Aires, Rio de Janeiro; Shanghai and Tianjin in China; Alexandria and Cairo in Egypt; Mumbai and Kolkata in India; Jakarta in Indonesia; Tokyo and Osaka-Kobe in Japan; Lagos in Nigeria; Karachi in Pakistan; Bangkok in Thailand, and New York and Los Angeles in the United States, according to studies by the United Nations and others.
More than one-tenth of the world's population, or 643 million people, live in low-lying areas at risk from climate change, say U.S. and European experts. Most imperiled, in descending order, are China, India, Bangladesh, Vietnam, Indonesia, Japan, Egypt, the U.S., Thailand and the Philippines.
The world’s oceans are becoming more acid, with potentially devastating consequences for corals and the marine organisms that build reefs and provide much of the Earth’s breathable oxygen.
The acidity is caused by the gradual buildup of carbon dioxide (CO2) in the atmosphere, dissolving into the oceans. Scientists fear it could be lethal for animals with chalky skeletons which make up more than a third of the planet’s marine life.
“Recent research into corals using boron isotopes indicates the ocean has become about one third of a pH unit more acid over the past fifty years. This is still early days for the research, and the trend is not uniform, but it certainly looks as if marine acidity is building up,” says Professor Malcolm McCulloch of CoECRS and the Australian National University.
“It appears this acidification is now taking place over decades, rather than centuries as originally predicted. It is happening even faster in the cooler waters of the Southern Ocean than in the tropics. It is starting to look like a very serious issue.”
If there's a ground zero for the epic drought that's tightening its grip on the South, it's once-mighty Lake Lanier, the Atlanta water source that's now a relative puddle surrounded by acres of dusty red clay.
Tall measuring sticks once covered by a dozen feet of water stand bone dry. "No Diving" signs rise from rocks 25 feet from the water. Crowds of boaters have been replaced by men with metal detectors searching the arid lake bed for lost treasure.
Lake Lanier's the primary source of drinking water for more than 4 million people, reports CBS News correspondent Mark Strassmann. But levels have plunged to eight feet below normal. And without rain in another month, levels could drop another five feet, passing the record low.
"This lake is a survivor," Jeff "Buddha" Powell told a worried customer at his bait shop along the barren banks.
"If you panic, you don't help Mother Nature," he added. "It's going to rain when it rains."
But this is a once-a-century drought, reports Strassmann. In the best estimate, without rain, metro-Atlanta has 120 days left of usable drinking water.
That dire prediction has some towns considering more drastic measures than mere lawn-watering bans, including mandatory rationing that would penalize homeowners and businesses if they don't reduce water usage.
"We're way beyond limiting outdoor water use. We're talking about indoor water use," said Jeff Knight, an environmental engineer for the college town of Athens, 60 miles northeast of Atlanta, which is preparing a last-ditch rationing program as its reservoir dries up.
Strong worldwide economic growth has accelerated the level of greenhouse-gas emissions in the atmosphere to a dangerous threshold scientists had not expected for another decade, according to a leading Australian climate change expert.
Scientist Tim Flannery told the Australian Broadcasting Corp. that an upcoming report by the U.N. Intergovernmental Panel on Climate Change will contain new data showing that the level of climate-changing gases in the atmosphere has already reached critical levels.
"What the report establishes is that the amount of greenhouse gas in the atmosphere is already above the threshold that can potentially cause dangerous climate change," Flannery told the broadcaster late Monday. "We are already at great risk of dangerous climate change, that's what these figures say. It's not next year or next decade — it's now."
The world moved into 'ecological overdraft' on Saturday, the point at which human consumption exceeds the ability of the earth to sustain it in any year and goes into the red, the New Economics Foundation think-tank said.
Ecological Debt Day this year is three days earlier than in 2006 which itself was three days earlier than in 2005. NEF said the date had moved steadily backwards every year since humanity began living beyond its environmental means in the 1980s.
"As the world creeps closer to irreversible global warming and goes deeper into ecological debt, why on earth, say, would the UK export 20 tonnes of mineral water to Australia and then re-import 21 tonnes," said NEF director Andrew Simms.
"And why would that wasteful trade be more the rule than the exception," he added.
Not only was there a massive gulf between rich and poor but there were deep variations in environmental profligacy between the rich countries, NEF said.
The Soviet Union successfully launched Sputnik I fifty years ago on October 4th, marking the beginning of our use of space for political, military, technological, and scientific ends. Since then we have launched hundreds of satellites, space probes, telescopes, moon missions, and planetary landers.
Now, political scientist Rasmus Karlsson suggests that space could provide us with a sustainable future not possible from an earthbound only perspective.
Karlsson, a researcher at the University of Lund, Sweden, explains that over the years, two strands of thought on sustainable development have emerged. They are ecologism and environmentalism.
Ecologism offers a solution by emphasizing the need for major socioeconomic reform aimed at a post-industrial era. Environmentalism, in contrast, focuses on the preservation, restoration, and improvement of the natural environment within the present framework.
However, Karlsson, suggests that there is a third approach to sustainable development that has until now been excluded from the agenda - namely a large-scale industrial expansion into space.
Unprecedented warm temperatures in the High Arctic this past summer were so extreme that researchers with a Queen's University-led climate change project have begun revising their forecasts.
"Everything has changed dramatically in the watershed we observed," reports Geography professor Scott Lamoureux, the leader of an International Polar Year project announced yesterday in Nunavut by Indian and Northern Affairs Minister Chuck Strahl. "It's something we'd envisioned for the future – but to see it happening now is quite remarkable."
Melting Arctic sea ice has shrunk to a 29-year low, significantly below the minimum set in 2005, according to preliminary figures from the National Snow and Ice Data Center, part of the University of Colorado at Boulder. NASA scientists, who have been observing the declining Arctic sea ice cover since the earliest measurements in 1979, are working to understand this sudden speed-up of sea ice decline and what it means for the future of Earth's northern polar region.
"The decline in the amount of thick ice that survives the summer melt season this year is quite remarkable," said Josefino C. Comiso, senior scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. "The extent of this 'perennial' sea ice and the area it covers are both nearly 38 percent lower than average. Compared to the record low in 2005, the extent and area are 24 percent and nearly 26 percent lower this year, respectively."
"From what we know of how Arctic sea ice behaves after nearly 30 years of continuous satellite observations, this kind of drop in sea ice usually takes more than three years to happen. The rapid trend of the perennial ice previously reported in 2002 appears now to be in an accelerated mode," Comiso observed.
The opening of the fabled Northwest Passage and the recent announcement that Arctic Sea ice has reached a new record summer low are just the tip of the iceberg when it comes to polar problems, so to speak.
Two new studies by scientists who keep an eye on sea ice melt have provided further evidence that the Arctic is currently suffering the brunt of global warming's effects, with the ice becoming thinner and winter ice also beginning to decline.
Ice melt in the summer is a normal phenomenon: As summer temperatures heat up the Northern Hemisphere, Arctic sea ice begins to melt, and its edge retreats and covers less of the North polar region. When temperatures begin to drop again in the winter, the ice reforms.
But in recent years, rising air and ocean temperatures, fueled by global warming, have caused more and more ice to melt each summer, with ice extent reaching a record low on Sept. 16 this year, according to the University of Colorado at Boulder's National Snow and Ice Data Center (NSIDC).
Winter sea ice, on the other hand, had remained fairly steady—until now.
Ultimately, rising seas will likely swamp the first American settlement in Jamestown, Va., as well as the Florida launch pad that sent the first American into orbit, many climate scientists are predicting.
In about a century, some of the places that make America what it is may be slowly erased.
Global warming - through a combination of melting glaciers, disappearing ice sheets and warmer waters expanding - is expected to cause oceans to rise by one meter, or about 39 inches. It will happen regardless of any future actions to curb greenhouse gases, several leading scientists say. And it will reshape the nation.
Rising waters will lap at the foundations of old money Wall Street and the new money towers of Silicon Valley. They will swamp the locations of big city airports and major interstate highways.
'Tis the season in the Arctic when the sun disappears below the horizon and twilight replaces daylight. Temperatures drop and ice that melted throughout the Arctic summer begins to cover the world's northernmost ocean again. Scientists have used satellite pictures since 1979 to map the extent of such ice at its minimum, and the picture this year isn't pretty. Covering 1.59 million square miles (4.12 million square kilometers), this summer's sea ice shattered the previous record for the smallest ice cap of 2.05 million square miles (5.31 million square kilometers) in 2005—a further loss of sea ice area equivalent to the states of California and Texas combined.
"The sea ice cover this year has reached a new record low," says Mark Serreze, senior research scientist at the U.S. National Snow and Ice Data Center in Boulder, Colo. "It's not just that we beat the old record, we annihilated it."
Scientists will be looking now to see how well the ice recovers
Arctic sea ice shrank to the smallest area on record this year, US scientists have confirmed.
The National Snow and Ice Data Center (NSIDC) said the minimum extent of 4.13 million sq km (1.59 million sq miles) was reached on 16 September.
The figure shatters all previous satellite surveys, including the previous record low of 5.32 million sq km measured in 2005.
Earlier this month, it was reported that the Northwest Passage was open.
The fabled Arctic shipping route from the Atlantic to the Pacific is normally ice-bound at some location throughout the year; but this year, ships have been able to complete an unimpeded navigation.
A thaw of Antarctic ice is outpacing predictions by the U.N. climate panel and could in the worst case drive up world sea levels by 2 meters (6 ft) by 2100, a leading expert said on Wednesday.
Millions of people, from Bangladesh to Florida and some Pacific island states, live less than a meter above sea level. Most of the world's major cities, from Shanghai to Buenos Aires, are by the sea.
Chris Rapley, the outgoing head of the British Antarctic Survey, said there were worrying signs of accelerating flows of ice towards the ocean from both Antarctica and Greenland with little sign of more snow falling inland to compensate.
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