Several new studies of ice loss at the earth’s poles paint a distressing picture of global warming‘s impact on those fragile ecosystems, and one study warns that changes in the Arctic climate can have a large impact on the rest of the world. In the first study, researchers determined that more than 2 trillion tons of landlocked ice in Greenland, Alaska, and Antarctica have melted since 2003, a melting trend that researchers expect to continue. Using new satellite technology that measures changes in mass in mountain glaciers and ice sheets, NASA geophysicist Scott Luthcke concluded that the losses amounted to enough water to fill the Chesapeake Bay 21 times. “The ice tells us in a very real way how the climate is changing,” said Luthcke [CNN].
Melting of land ice, unlike sea ice, increases sea levels very slightly. Between Greenland, Antarctica and Alaska, melting land ice has raised global sea levels about one-fifth of an inch in the past five years, Luthcke said. Sea levels also rise from water expanding as it warms [AP]. The amount by which sea levels will rise as a result of global warming is still uncertain. The UN’s Intergovernmental Panel on Climate Change gives an official estimate of a seven-inch to two-foot rise by 2100, but researchers say conditions at the poles are changing too quickly for confident predictions.
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In the wake of a distressing report about accelerating deforestation in the Amazon rainforest, the Brazilian government has vowed to reduce the rate of land-clearing by 70 percent over the next decade. The government was called upon to take drastic steps after a report declared that deforestation increased this year for the first time since 2004 as surging prices for cattle and soybeans led ranchers to seek farm land in the forest. The world’s largest rainforest lost 11,968 square kilometers (4,600 square miles), an area about 10 times as large as New York City, in the 12 months through July 2008 [Bloomberg].
Tasso Azevedo, head of the Brazilian government’s forestry service said: “We can now adopt targets because we now have the instruments to implement them.” He was referring to a new Amazon fund, where foreign nations are being encouraged by Brazil to contribute financially to the conservation of the vast Amazon region [BBC News]. Norway has already agreed to contribute $1 billion to the fund over the next seven years on the condition that deforestation rates continue to drop during that time; however, Norway’s pledge is hoped to be just the beginning. The Brazilian government wants to raise $21 billion in donations to finance conservation and sustainable development projects, arguing that since the whole world receives climate benefits from an intact Amazon rainforest, the whole world should subsidize it.
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Ocean acidification is happening at 10 to 20 times the rate predicted by existing climate models, according to an eight-year study. The rapid acidification of the oceans is linked to global warming and may be a sign that the oceans, the largest absorber of atmospheric carbon dioxide, may not be as hardy as presumed. The changes threaten disaster for marine life with shells that are easily corroded by acid. Marine biologist Nancy Knowlton said, “This is typical of so many climate studies—almost without exception things are turning out to be worse than we originally thought.” [National Geographic News].
The study was done around Takoosh Island off the coast of Washington state and represents the first detailed dataset on variations of coastal pH at a temperate latitude, where the world’s most productive fisheries are found [Times of India]. The researchers took over 24,000 measurements of ocean pH over an 8-year period. During that time, the pH of the seawater was predicted to decrease by only 0.015 points. Instead, the data showed that seawater pH dropped by 0.36 to about 8.1. “The increase in acidity we saw during our study was about the same magnitude as we expect over the course of the next century,” said study co-author Timothy Wootton [National Geographic News].
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Using boat, tags, nets, and submarines, marine biologists from 82 nations have been canvassing the oceans for the first Census of Marine Life, an ambitious effort to get a rough tally of all the creatures in the world’s oceans. The 10-year project is expected to conclude in 2010, and researchers say the broad survey will help them observe changes to marine ecosystems. Says co-senior scientist Ron O’Dor: “We are moving into this period of global warming, which is resulting in the acidification of the oceans, melting of the polar ice cap. We can use the first census as a benchmark to see what happens in the oceans over the next decade or more” [BBC News].
Although the project still has two years to go, researchers have already made a host of startling discoveries, many of which will be discussed this week at the World Conference on Marine Biodiversity in Valencia, Spain. In one study, researchers conducted a genetic analysis of deep sea octopuses from around the world, and determined that most descended from a common ancestor species that still lives near Antarctica. Researchers believe that octopuses started migrating to new ocean basins more than 30 million years ago when, as Antarctica cooled and a large icesheet grew, nature created a “thermohaline expressway,” a northbound flow of tasty frigid water with high salt and oxygen content. Isolated in new habitat conditions, many different species evolved; some octopuses, for example, losing their defensive ink sacs — pointless at perpetually dark depths [LiveScience].
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Warmer winters in Norway seem to be causing a decline in lemming populations, according to a new study, and researchers say the decline of the rodent is having a cascading effect. Lemming predators, like foxes and owls, have been forced to hunt different prey in what researchers call a clear-cut example of how global warming can have a disruptive impact on entire ecosystems.
Lemming populations throughout Scandinavia tend to explode naturally every three to five years, causing huge numbers to go in search of food. Occasionally this leads the rodents to jump into water and swim to new pastures new—the origin of the myth that lemmings commit mass suicide. When lemmings boom, they’re hard to miss. Norwegians have had to use snowplows to clear the squashed rodents off the roads [National Geographic News]. But the study of lemming populations during the last four decades found no population explosions since 1994.
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Pity the poor frogs: they’re one of the most endangered group of vertebrates on the planet, and new research shows that two of the factors in their plight are common, everyday farm chemicals. The study shows that atrazine, a weedkiller that’s widely used in agricultural areas, not only boosts the levels of parasitic flatworms in frog ponds, it also decreases tadpoles’ ability to fight off infections. If that wasn’t bad enough, previous research has found that runoff from phosphate fertilizers also boosts parasite levels. Taken together, researchers say, the weedkiller and the fertilizers are hitting frogs with a double whammy.
Amphibian populations around the world have been declining in recent decades, with many species on the brink of extinction. Infection with any of several species of tiny flatworms, known as trematodes, can trigger debilitating limb deformities in frogs. Severe infections can kill the amphibians. The question was why high rates of those deformities — and, presumably, trematode infections — began showing up across the nation in the mid-1990s [Science News]. The new findings suggest that the growing prevalence of the weedkiller atrazine in corn-growing regions since that time may be partly to blame for the woeful state of American amphibians.
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Two different studies separated by more than 1,700 miles hammer home the same point: evidence of global warming is everywhere. In Yellowstone National Park, researchers found that amphibian populations have declined dramatically over the past 15 years as some of their pond habitats have dried up and disappeared. Meanwhile, in Massachusetts’ Walden Pond, botanists discovered that more than a quarter of the plant species observed by Henry David Thoreau have disappeared since the author went to the woods to “live deliberately” in the 1850s.
The two studies, which both appear in the Proceedings of the National Academy of Sciences [subscription required], show that changes to the planet’s flora and fauna are already well underway. The Yellowstone study compared data from an amphibian survey done in 1992 and 1993 to data from a new survey conducted over the last three summers; researchers looked at the park’s “kettle” ponds, which are re-filled in spring by groundwater and snow melt running down from the hills [BBC News]. The researchers found that the number of permanently dry ponds had quadrupled, and even in the ponds that remained, amphibian populations had plummeted.
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Global warming isn’t just a threat to polar bears in the rapidly warming Arctic, a new study says: Species in the tropics are beginning to feel the effects as well, and it will only get worse. Researchers surveyed more than 1,900 species of plants, insects, and fungi in a Costa Rica rainforest and came to the troubling conclusion that if world temperatures continue to rise as predicted over the next 50 years, half of those species will have to move to completely new territory to find an appropriate habitat.
The situation is complicated for tropical species, says lead researcher Robert Colwell; shifting north or south doesn’t bring significantly lower temperatures, so species will have to take up residence at higher altitudes to survive. In the absence of mountainsides to serve as a cool refuge, those plants and insects that cannot face higher temperatures may disappear as it would require migrations of hundreds or even thousands of miles to find a suitable cooler climate—crossing habitats utterly changed by human impacts. “For lowland tropical species whose geographical range lies far from mountains, for example in the middle of the Amazon,” Colwell says, “the prospect for extinction cannot be dismissed” [Scientific American].
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Almost two miles beneath the earth’s surface in a South African goldmine, researchers have found a new species of bacteria that lives in total isolation from any other organism. The discovery offers the first known example of an ecosystem that isn’t a complex web of different life forms, but is instead hosts just one self-sufficient species. The bacteria, Desulforudis audaxviator, is able to extract all its food and energy directly from the surrounding water and rocks, and researchers say the independent microbe offers a glimpse of the shape life could take on other planets.
Researchers wanted to know what organisms were living in the mine’s deep fissures, a habitat completely devoid of light and oxygen, so they analyzed the genes present in a water sample to determine what species lived there. They filtered a total of 5,600 liters of mine water to get their sample, which gave other microbes plenty of opportunities to make themselves known. Of the DNA sequences obtained from this sample, over 99.9 percent were from this single species; over half of the remainder were obvious contaminants from their own lab [Ars Technica].
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An ambitious, multibillion-dollar effort to restore Florida’s Everglades is floundering due to bureaucratic delays, and the ecosystem may be close to a tipping point, according to a new congressionally mandated report. The longer the project remains stalled, the higher its cost will rise — even as the River of Grass that it’s supposed to rescue declines, the report from the National Research Council says. “If we don’t do something soon, we’re going to lose this really precious resource,” said [report coauthor] William Graf [St. Petersburg Times].
The report criticizes progress on the Comprehensive Everglades Restoration Plan, which was approved by Congress in 2000. The massive effort to restore natural water flow to about 4 million acres of wetlands was originally estimated to cost about $7.8 billion and take 30 years to complete — a price tag that has since ballooned due to rising costs…. The 2000 plan made the federal government and Florida 50-50 partners. To date, the state has committed more than $2 billion and pushed ahead alone with a few projects. Congress has only appropriated several hundred million dollars [AP].
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The introduction of genetically engineered cotton plants has had an unexpectedly broad effect on Chinese agriculture, according to a new study. The so-called Bt cotton plants that produce a chemical that kills the cotton bollworm have not only reduced the incidence of the pest in cotton fields, but also in neighboring fields of corn, soybeans, and other crops. The study, published in the journal Science [subscription required], found that the altered cotton plants kill the bollworm larvae before they can mature and move on to other crops.
The cotton bollworm, Helicoverpa armigera, is one of the most serious insect pests in Asia, attacking wheat, corn, soya beans, peanuts and vegetables as well as cotton. In the early 1990s, repeated bollworm outbreaks in China were barely contained. The heavy pesticide use that controlled them killed thousands of people each year, according to [biotechnology researcher] Huang Dafang [Nature News], as many farmers didn’t wear protective gear while they drenched their crops with chemicals.
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Researchers have found that a one-year temperature spike can decrease the amount of carbon dioxide absorbed by a grassland ecosystem for up to two years. The four-year experiment, conducted at the Desert Research Institute in Nevada, adds a troubling new factor to calculations on how to best cope with global warming. Grasslands and their soils are considered a major sink for excess atmospheric carbon dioxide. Such natural carbon sponges, if they continue to thrive, could help alleviate the warming effects of manmade CO2 emissions [Science News].
In the experiment, which was described in the journal Nature [subscription required], researchers removed 12 large plots of grass with the underlying six feet of soil and microbes, each taken from the Oklahoma prairie in one piece. The plots were transported to the institute’s greenhouses, where the ecosystems were carefully controlled. Half the plots were exposed to normal fluctuations of temperature and rainfall, while the other half were subjected to one year where temperatures were consistently 7 degrees Fahrenheit hotter than usual.
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In a cluster of coal mines in eastern Illinois, researchers have discovered the fossilized remains of ancient rainforests that date from the Carboniferous era, including one forest that stretched for 39 square miles. Researchers say the forests date from both before and after an episode of intense global warming that occurred about 306 million years ago, and may shed light on the ecosystem‘s reaction to the drastic climate shift.
Researchers published a report on the first fossilized rainforest last year, but announced this week at the British Association’s Festival of Science that they have since come across five more patches of ancient woods. Says paleontologist Howard Falcon-Lang: “Three of the forests predate global warming and the rest follow it, so we can compare the ecology of those rain forests to see what the effect of global warming was.” During that period the Earth’s climate flipped from being covered with large polar icecaps to a greenhouse state that was completely ice-free, he added [National Geographic News].
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The Environmental Protection Agency has vetoed a massive flood control project that was in the works for seven decades. The move – which puts the kibosh on the proposed Yazoo Pumps Project to reduce flooding between the Mississippi and Yazoo rivers – is only the 12th time the Environmental Protection Agency has used its authority to scrap a project under the Clean Water Act [Scientific American].
The EPA’s decision is being hailed as an environmental victory, as the plan called for massive pumps that would have drained water out of at least 67,000 acres of wetlands, irrevocably altering the ecosystem. The landscape of swamps, bayous, and cypress trees is vital to an extensive range of wildlife, including fish, migrating birds, and the endangered Louisiana black bear; the wetlands are valued not only by conservationists, but also by hunters and commercial fishermen.
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A team of architects and environmental engineers has proposed covering swaths of the Sahara with vast “salt water greenhouses” powered by solar power arrays, in a plan they call the Sahara Forest Project. Charlie Paton, inventor of the salt water greenhouse, says the combined technologies could transform patches of the desert from arid wastelands into lush expanses that produce a bounty of fruits and vegetables for local people.
The plan is no doubt ambitious and unproved at this scale, but Paton says he has built demonstration greenhouses on the Spanish island Tenerife, as well as in Abu Dhabi and Oman; he says there is further interest in funding demonstration projects from across the Middle East, including UAE, Oman, Bahrain, Qatar and Kuwait. The cost is not as astronomical as one would think, and is estimated at approximately $118 million for a 20 hectare [50 acre] site of greenhouses and a 10MW concentrated solar power farm [Red Herring]. Paton is working with Exploration Architecture, a company that worked on the world’s largest greenhouse in England’s Eden Project.
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