Cushy
from The annotated budak
31 Jan 2013, Thursday: 4pm @ DBS CF2: Dr David Edwards on The Biodiversity Value of Degraded Tropical Forests from The Biodiversity crew @ NUS
Typhoon Bopha decimated coral reefs
from Mongabay.com news by Jeremy Hance
Channel NewsAsia 24 Jan 13;
SINGAPORE: Another 80 HDB residential blocks in Punggol Eco-Town will be solar powered.
The Housing and Development Board (HDB) has awarded a tender to lease three mega-watt-peak solar photovoltaic (PV) systems for the blocks.
The tender attracted keen competition from the industry, with a total of 13 bidders, compared to the first Solar Leasing project in 2011 which only garnered three bids.
Under the tender, solar system developer Sunseap will design, finance, install, operate and maintain the solar PV systems.
Pasir Ris-Punggol Town Council will have a service agreement with Sunseap to pay for the solar power generated and used, at a preferential rate of up to 5 per cent discount off the retail electricity tariff rate.
Installation works are scheduled to be completed by 2014.
HDB is currently the largest stakeholder in the installation of solar PV system in Singapore.
To date, HDB has committed a total of S$15 million for the installation of solar PV systems for 175 blocks of flats. This is equivalent to powering the energy needs of 1,800 4-room flats for a year.
With the second solar leasing project, HDB has moved a step closer to the aim of developing Punggol Eco-Town as a net zero energy town by 2016.
Dr Cheong Koon Hean, HDB's chief executive officer, said: "Punggol, as Singapore's first eco-town, serves as a 'living laboratory' to test new ideas and technologies in sustainable development.
"The expansion of our solar PV installations through solar leasing is in line with the second thrust of HDB's 'Roadmap for Better Living' -- to develop sustainable towns.
"Solar technology has been given an extra boost with our largest tender ever under the Solar Capability Building Programme which aims to test-bed solar PV technology in 200 public housing blocks by 2015.
"The scheme will help enhance the industry's capabilities and test the feasibility of implementing solar technology on a wider scale when it becomes more cost effective."
In a blog post, National Development Minister Khaw Boon Wan said Singapore, being in the tropics, should potentially be a great user of solar energy.
He said although solar energy technology is still expensive, the economics are getting better every day.
Mr Khaw added that people should experiment, with the government providing financial incentives to help spawn more pilots.
- CNA/al
More Punggol flats to go solar
Another 80 HDB blocks will use sunlight to power common facilities
Daryl Chin Straits Times 25 Jan 13;
SOLAR panels will be installed in another 80 Housing Board blocks in eco-town Punggol to harness energy to power services in common areas.
Facilities such as lifts, lights in corridors and staircases and water pumps will use the energy, the HDB said yesterday.
This will take the town a step closer towards relying entirely on solar power for common services by 2016, it added.
Commenting on his blog, National Development Minister Khaw Boon Wan said that while solar energy is still more expensive than energy produced from oil or gas, that should not deter efforts to go green.
He noted that the greater use of solar technology has been fuelled in part by the falling cost of solar photovoltaic cells.
The costs have dropped some 60 per cent since HDB first tested using solar panels on the top of HDB blocks in Serangoon North and Sembawang in 2008.
"As solar panels improve on their efficiency and their cost of production drops, the economics of solar energy is getting better every day," he said.
To encourage more companies to bid to set up the solar panels, the HDB offsets up to 30 per cent of the start-up costs.
The firm that won the 20-year contract sells the energy tapped to Pasir Ris-Punggol Town Council at up to 5 per cent off the retail electricity tariff rate.
Mr Khaw believes that this leasing arrangement would enable more flats to benefit from the technology.
The HDB said the initial capital outlay from the Government acts as an incentive, as contractors bidding for the project can take about 20 years before they recover operational costs.
The cost of the system in the latest tender is $8.84 million, of which the HDB will foot $645,000. In a previous tender in 2011, also in Punggol, the winning bid was $10.9 million for a less advanced system that covered 45 blocks. The Housing Board put up $3.28 million. Solar developer Sunseap won both bids.
HDB chief executive Cheong Koon Hean said the latest move is in line with its vision to create sustainable towns.
National University of Singapore researcher Kua Harn Wei said that while investing in greener gadgets and equipment is a must, society should not forget that it is also about "sustainable consumption".
Small things, like switching on the lights only when necessary, can help.
To date, the HDB has committed a total of $15million to install solar systems for 175 blocks of flats. The energy harnessed is enough to meet the needs of 1,800 four-room flats for a year.
The aim is to test-bed such technology in 200 public housing blocks by 2015.
Said Punggol resident Eric Tong, 33, a businessman: "It's great that my town is going greener, but of course it will be better when conservancy charges also fall."
Solar energy to light up more HDB blocks
Developer wins tender to maintain, operate photovoltaic systems in Punggol Eco-Town
Then Ai Ping Today Online 25 Jan 13;
SINGAPORE — Eighty more blocks of public housing in Punggol Eco-Town will be powered by solar energy by next year, as solar power — once considered too expensive for widespread use — becomes an “increasingly viable” energy solution, said the Housing and Development Board (HDB).
The HDB announced yesterday that it had awarded a tender to solar system developer Sunseap to lease three mega-watt-peak (MWp) solar photovoltaic (PV) systems for these HDB blocks.
The power generated will power common areas such as lifts and corridors, as well as staircase lighting and water pumps.
The tender attracted “keen competition”, with 13 bidders compared to the first solar leasing project in 2011 which only had three bids, said the HDB.
National Development Minister Khaw Boon Wan said in a blog post yesterday that, while solar energy was not yet cheaper than energy produced from oil or gas, the economics were “getting better every day”.
“We should not wait until the economics is fully proven,” he said. “We should experiment, pilot and acquire the necessary experience while the scientists work hard in the research lab.”
Since the HDB first tested solar PV systems in 2008, global prices of solar PV cells have fallen rapidly. “When we started in 2008, the price of a solar panel was S$5.17/Wp. It has since dropped by 60 per cent,” he said.
Solar leasing from the private sector — where the HDB offsets a portion of the company’s start-up costs and the company takes care of the subsequent operational and maintenance costs — has also allowed residents to enjoy a lower electricity tariff. This way, the HDB need not procure and install the PV systems and town councils need not maintain them.
“For example, in the recent solar leasing project, the Pasir Ris-Punggol (Town Council) gets up to 5 per cent discount off the retail electricity tariff rate for the solar energy generated,” Mr Khaw said.
The initial capital outlay offered by the Government under the solar leasing model is “necessary” as the current payback for solar remains long at about 20 years. However, outlay remains low due to the increased competition in the local market and cheaper prices of solar PV cells globally, the HDB said.
In the latest tender, the cost for a 3 MWp system is S$8.84 million and the system cost payable by the HDB is about S$645,000. In comparison, the cost for a 2 MWp system in the first tender was S$10.9 million, with the HDB paying S$3.28 million up front.
More than 100 HDB blocks have been fitted with solar PV systems in the last five years and the HDB aims to reach 200 blocks by 2015.
To date, it has committed S$15 million to install solar PV systems for 175 blocks.
Related links
Cheaper, cleaner, greener by Minister Khaw Boon Wan
Channel NewsAsia 24 Jan 13;
SINGAPORE: A new publication has shown that innovative planning, design and development practices that emphasise a "people-first" focus can help ensure that rapid urbanisation does not compromise liveability and sustainability.
The publication, 10 Principles for Liveable High Density Cities: Lessons from Singapore, draws upon Singapore's successful urbanisation experience.
It was published by the non-profit education and research centre, Urban Land Institute and Singapore's Centre for Liveable Cities.
The ten principles which include planning for long-term growth and renewal and embracing diversity and fostering inclusiveness were developed during two workshops hosted by both organisations.
Other principles are drawing nature closer to people, developing affordable, mixed-use neighbourhoods, making public spaces work harder, prioritising green transport and building options, relieving density with variety and adding green boundaries, activating spaces for greater safety, promoting innovative and non-conventional solutions, forging "3P" - people, public, private partnerships.
Discussions at the first workshop centred around four case study districts in Singapore.
These were the mixed-use downtown district of Marina Bay, the commercial corridor of Orchard Road and two new public housing developments in Toa Payoh and Tampines.
Both organisations considered the districts to be both densely populated and highly liveable.
The ideas and principles generated were further developed, corroborated, and condensed into ten principles.
In the foreword to the publication, Minister for National Development Khaw Boon Wan pointed out the lasting benefits of building cities for people.
He said maintaining a good quality, liveable high-density urban landscape in which all Singaporeans can find and make a home is crucial to the survival of the Singapore nation.
- CNA/xq
Melissa Hogenboom BBC News 24 Jan 13;
Most of the world's plant and animal species could be named before they go extinct, claim researchers.
Writing in the journal Science, the researchers said it could be achieved this century.
This is largely due to an increase in taxonomists - the people who describe species new to science.
Although there is an extinction crisis, the rates are lower than previously expected, the scientists report.
Discovering and naming the world's species is critical for their conservation and can be done with only a modest increase in effort, the researchers stated.
But they also recognised it will be difficult to maintain a high rate of discovery as it becomes harder to find rare species.
Previous overestimates of the number of species - some as high as 100 million, led some in the scientific community to believe that it would be impossible to name all the world's species before they go extinct.
Naming a species gives formal recognition to its existence, making conservation easier, said lead author, Associate Professor Dr Mark Costello, from The University of Auckland.
"We believe that with just a modest increase in effort in taxonomy and conservation, most species could be discovered and protected from extinction."
As more information on taxonomy is available to the public via the internet, amateur as well as professional taxonomists are increasing, especially in regions such as Asia and South America, which are rich in biodiversity.
"We've discovered three times more people now naming species than there were ever before. We're in the golden age of taxonomy," added Dr Costello.
He hopes that this increase will continue, and that the public become more involved.
There are currently around around 1.5 million species which have been named. Dr Costello and his colleagues estimate the total number species on Earth ranges from two to eight million.
"Overestimates of the number of species on Earth are self-defeating because they can make attempts to discover and conserve biodiversity appear to be hopeless," said Dr Costello.
Jean-Christophe Vie, deputy director of the International Union for Conservation of Nature species programme, disagrees with the review's conclusion that "species are more likely to be described than become extinct".
"Extinction is usually underestimated. It's more important to fight extinction than to describe or catalogue all species," he said.
"We can protect species even if we don't know all of them. I have no doubt we can catalogue all of life, and it would be useful, but we don't have the luxury of time."
"I am worried by the message implying that to conserve species you need to know everything about them. You can do a lot of protection even in the absence of knowledge."
To increase the time it takes to name the world's species, Dr Costello and colleagues recommend more taxonomists to be employed, increased financial support and international coordination in the scientific community to share expertise.
Professor Georgina Mace, from the Centre for Population Biology at Imperial College London, welcomes the analysis but also questions whether we really need to know the names of all species.
"Its excellent news, that taxonomic expertise is moving very effectively to tropical countries where most of the biodiversity on Earth is," she said.
She added that with sensible sampling, conservationists can prioritise effort on groups of species that are disappearing in the places most under threat.
"Once you've done that you can put in place conservation actions that will benefit everything there, whether named or not."
"It is part of our cultural responsibility to have looked at every single species of earth, but because it can be difficult to do, particularly the last few percent. We need to be quite strategic about the effort put into discovering, describing, monitoring and conserving."
The levels of investment needed to name all the species is very modest, in global terms, said Professor Ken Norris, director of centre for Agri-Environmental research at Reading University.
He added that many species play important functional roles in the way Earth works and the life support systems they provide.
"If we lose them, important functions of those systems - like purifying weather, providing fertile soils and clean air - might be damaged without us realising what we've lost," Prof Norris explained.
"Extinction isn't just about losing part of Earth's evolutionary history, it might also involve fundamental changes in the Earth's ecosystems that may have detrimental effects on mankind."
Naming species before extiction
The University of Auckland Science Alert 25 Jan 13;
Claims that most species will go extinct before they can be discovered have been debunked in the latest issue of Science, by researchers from The University of Auckland, Griffith University, and the University of Oxford.
The scientists show that the claims are based on two key misconceptions: an over-estimation of how many species may exist on Earth, and the erroneous belief that the number of taxonomists (people who describe and identify species) is declining.
“Our findings are potentially good news for the conservation of global biodiversity,” says lead author Associate Professor Mark Costello from The University of Auckland’s Leigh Marine Laboratory, who published the work with Professor Nigel Stork from Griffith University and Professor Bob May from Oxford.
The authors propose that there are 5 +/- 3 million species on Earth – far fewer than has been widely believed – of which 1.5 million species have been named. This re-affirms previous estimates by the three authors, which spanned the upper and lower reaches of this range.
“Over-estimates of the number of species on Earth are self-defeating because they can make attempts to discover and conserve biodiversity appear to be hopeless,” says Dr Costello. “Our work suggests that this is far from the case. We believe that with just a modest increase in effort in taxonomy and conservation, most species could be discovered and protected from extinction.”
The authors conclude that there have never been so many people describing new species – including professionals and amateurs, the number may near 50,000. And the community continues to grow, in large part due to the development of science in Asia and South America, regions that are rich in biodiversity and where many new species are being discovered.
While the research suggests that species are more likely to be discovered than to go extinct, the authors do not underplay the seriousness of the threats to species and their habitats. The combination of over-hunting, habitat loss and climate change, now occurring at both local and global scales, mean that extinction rates could increase very rapidly in the future.
Dr Costello says that the discovery and naming of species is critical to their conservation. Naming a species gives formal recognition to its existence, making its conservation far easier. The process of discovery, including exploration of remote and less studied habitats, also provides the evidence to underpin conservation efforts.
Amongst the authors’ recommendations to increase the rate of species discovery are: getting more people involved in the work; international coordination of exploration and specimen collections; the development of freely available online databases; and financial support from governments and other organisations for these efforts.
The current research is published in Science: Costello MJ, May RM, Stork NE. (2013) Can we name Earth’s species before they go extinct?
Most Species on Earth Could Be Recorded, Study Finds
Douglas Main LiveScience.com Yahoo News 7 Feb 13;
What strange creatures dwell in the rainforests, at the bottom of the ocean or even in plain sight in our cities? If we don't look, we'll never know, one group of researchers says.
A study published Jan. 24 in the journal Science suggests that discovering and recording all of Earth's biodiversity may not be as difficult as previously thought, and could be accomplished with a "realistic surge of effort," said study co-author Mark Costello, a researcher at New Zealand's University of Auckland. By spending between $500 million and $1 billion annually for the next 50 years, humans could describe most species on Earth, Costello told OurAmazingPlanet.
Costello and his two co-authors also calculated that extinction rates are not as high as many scientists previously thought. The study suggests that species are currently being discovered faster than they go extinct, contradicting a widely held tenant amongst scientists that the opposite is currently happening amidst the biggest mass extinction since the dinosaurs were wiped out tens of millions of years ago. Though some scientists welcome the focus Costello and his colleagues are placing on the need to catalog Earth's species, they don't necessarily agree with their conclusions.
How many species are there?
Estimations of the number of species that live on Earth vary considerably, from as few as 2 million to as many as 100 million species. Costello's paper suggests there are between 2 million and 8 million species, at the low end of many scientists' estimates. It is difficult to tell exactly how many species there are without counting them, of course; different environments (many little-studied) have different levels of biodiversity, making it difficult to come up with a global number, and little is known about remote environments like the deep sea, for example.
There are currently more than 1.5 million species described, but the exact number is uncertain due to overlapping descriptions of the same species, as well as the lack of digitization of many databases and collections, said Mike Novacek, the provost of science at the American Museum of Natural History in New York, who was not involved in the study. [Earth Quiz: Do You Really Know Your Planet?]
Although the amount of money Costello and his colleagues say will be needed to count Earth's species may seem like a lot, it pales in comparison to what we spend on sports, entertainment and space exploration. Knowing how many species are on Earth is vital to understanding life itself, Costello said.
"It's part of exploring our own planet. It is the first step in understanding ecosystems and as fundamental to biology as naming particles is to physicists, or describing elements is to chemists," he said.
Novacek said that he welcomed the paper's emphasis on recording species and conservation. "It's a cultural embarrassment that we know so little about life on this planet," he said. However, the paper's estimates of species extinction were a little low, he added.
Camilo Mora, a biologist at the University of Hawaii, went further, saying he thought the study significantly underestimated the number of extinctions occurring worldwide, making the current extinction crisis appear less worrisome than it is.
Extinction rates are also important to know because every organism serves a unique role in its ecosystem, which suffers when species are lost. Healthy ecosystems can make for cleaner water and air, as well as ensure the survival of important resources. Even people in cities and towns reap the benefit of far-flung biodiversity; for example, many modern drugs (like quinine, used to treat malaria) have originated from chemicals found in rainforest plants.
The study
The new study was a review of newly published research on extinction rates and discoveries of new species. Costello said that his team's approach was novel because it attempted to calculate global levels of biodiversity by looking at the sum of individual ecosystems the world over. Other calculations of extinction may have overstated the problem by taking local numbers and applying them globally, which Costello's team took pains not to do, he said. High levels of biodiversity in one patch of rainforest may not be paralleled in other areas of rainforest or temperate forest, for example, he said. [8 of the World's Most Endangered Places]
Costello's team also suggests that there are more papers than ever describing new species, thanks to the involvement of a growing number of scientists who don't typically specialize in taxonomy, as well as amateur scientists, he said. For that reason, the task of describing the world's species may not be as insurmountable as thought, he added.
Observed rates of extinction haven't been as high as predicted by some, due in part to better conservation efforts worldwide and the survival of animals in "secondary" habitats like agricultural areas, Costello said. Species can hang on in these degraded habitats longer than expected, giving conservationists a chance to save them before they disappear, he said. Pristine habitats are nevertheless vital to protect, he added.
Controversy
But not everyone agrees with the assessments and conclusions of Costello and his co-authors.
Even the median rate of extinction suggested in Costello's paper — at 25,250 per decade — is disturbing for the planet, Novacek said, while the lower bound of the estimate (500 extinctions per decade) sounded a little low and was "optimistic," to say the least.
Mora's criticism went further: "They paint a very nice glossy picture of the reality of what's happening out there," Mora told OurAmazingPlanet. "But it doesn't represent the reality."
For example, Mora said his "mind was blown" (in a negative way) by the 500-extinctions-per-decade suggestion. Habitat loss alone leads to 25,000 extinctions per year, he said. "And that's just because of habitat loss. Now start adding all the stressors — like climate change, invasive species, pollution — and the number is likely to go a lot higher," he said.
Mora also disagreed with the paper's assertion that the number of qualified taxonomists is growing worldwide. While there may be more authors of papers describing new species, many of these consist of amateurs or nontaxonomists who do not have the necessary expertise to provide leadership in the field, he said. There are fewer full-time positions for taxonomists and many experts in their fields aren't being replaced once they retire, Mora said, a view with which Novacek agreed. [Amazing Species Discovered in 2012]
Extinction crisis
All sides could agree, however, that we are in the midst of an enormous extinction crisis, the largest since the disappearance of the dinosaurs 65 million years ago, and that we must do more to record and conserve these species before they vanish. "The dinosaurs disappeared because of an asteroid, and in this case we are the asteroid," Novacek said.
All sides agreed that humans could — and should — record most species, although opinions on exactly how much effort or money it might take differed. In the short-term, smaller efforts could make a big difference, Costello said.
"We estimate the backlog in undescribed species in collections could be cleared by hiring 500 new taxonomists for 10 years," he said, which would cost about $5 million per year, and help pave the way for the more expensive and time-consuming process of describing new species found in the wild.
"In the end, there's going to be some controversy and dialogue about these numbers, but I'm glad the paper is coming out and that the issue [of extinction and conservation] is being discussed, because it's so important," Novacek said.
Paulo Prada PlanetArk 25 Jan 13;
After years of gains against destruction of the Amazon rainforest, Brazil appears to be suffering from an increase in deforestation as farmers, loggers, miners and builders move into previously untouched woodland, according to data compiled by the government and independent researchers.
Imazon, a Brazilian research institute that tracks deforestation through satellite imagery, said in a recent report that destruction in the world's largest rainforest climbed for the fourth consecutive month in December.
In the last five months of 2012, Imazon detected clearings of 497 square miles (1,288 square km) of woodland - a Los Angeles-size total that is more than twice as big as the combined areas detected in the last five months of 2011.
Preliminary data from Brazil's space agency, which produces its own monthly estimates, also suggests an increase in deforestation between August and October, the last month for which its figures have been released.
Researchers and government officials say more data is needed to confirm that a full-fledged reversal is under way after what had been a sustained reduction in deforestation in recent years. Among other variables, clouds from the ongoing rainy season hinder definitive imagery. Additional data could also clarify whether new gaps in the rainforest canopy are the result of deliberate clearcutting and fires or of natural thinning.
If the increase continues, it would confirm fears raised by scientists and ecologists that changes to Brazil's environmental policies, growing inroads by developers and government-backed infrastructure projects are eroding gains in the fight to protect a region that has about 12 percent of the planet's fresh water, is an abundant source of oxygen and is home to an untold number of plant and animal species.
"The context is ripe for the destruction to intensify," said Paulo Moutinho, executive director of the Amazon Environmental Research Institute, a well-known not-for-profit group. "It's clear that the levels could easily continue to grow."
Government officials urge caution, noting the long-term trend in progress against deforestation. "It's too early to sound an alarm," said Francisco Oliveira, the director of policies against deforestation at Brazil's environment ministry. "A fuller picture will emerge once the clouds are gone."
CHALLENGING SCIENCE
Many factors drive deforestation.
Loggers and miners have long exploited hardwoods and ores in a jungle the size of Western Europe. As Brazil became an agricultural powerhouse in recent decades, soybean growers, cattle ranchers and others increasingly farmed cleared woodland.
Then there is the ongoing push to tap the Amazon region's rivers with hydroelectric dams - a process critics say lures people to areas that would otherwise remain untouched.
Tracking deforestation is a challenging science that relies on a mix of satellite data and on-the-ground reconnaissance.
Brazil's government and scientists at Imazon, a privately funded institute in the Amazon city of Belem, get preliminary evidence through satellite imagery. More conclusive data takes longer to compile and relies on slower higher-resolution visuals and on-site surveys by scientists and environmental inspectors.
The government releases an annual tally through July, when the region is driest and aerial views are the most clear.
Data showed that deforestation, through July 2012, had fallen to record lows for four consecutive years, largely because of stricter environmental enforcement.
A spike in 2007, when a surge in commodity prices sparked a rush for cropland, was curtailed after the government introduced steeper fines and blocked credit for offenders.
In response, loggers turned to smaller, more focused felling in efforts to evade satellite scans.
Now, scientists and environmental activists warn that violators are emboldened by regulatory changes, high global prices for agricultural exports and a scramble by settlers to get in on the economic activity around hydroelectric dams and other big infrastructure and industrial projects.
"You are going to see an increase in deforestation very soon," Marina Silva, a former environment minister and longtime Amazon activist, warned in a Reuters interview last year.
She and other critics have lambasted the government of President Dilma Rousseff, whose drive to revive Brazil's once-booming economy has wrought changes that environmentalists fear unleash destruction. Rousseff, for her part, has said the policies are both necessary and environmentally sustainable.
Among other regulatory changes, Brazil in late 2011 gave local officials more authority over the enforcement of environmental laws and in the process closed many of the federal outposts where forestry agents, especially in the vast and remote rainforest, represented the only obstacle to offenders.
Last year, Brazil revamped its "forestry code," longstanding rules for the types of woodland that must be preserved around developments. While the new code theoretically remains strict in the conservation it mandates, critics argue that enforcement will be difficult because of the handover to local officials.
Oliveira, the environment ministry official, said the federal government can still respond swiftly. Instead of relying on fixed bases, he explained, new units of environmental agents were created in recent months that can be deployed when needed -- making them "more agile" as violators clear smaller patches.
"Our methods and strategies are evolving," he said.
Still, scientists fear some of the damage could be happening before the government's very eyes. Government-backed dams, roads and mines are speeding a reversal, they argue, because they grant passage to previously isolated swaths of the Amazon.
"You have all these factors coming together making it much easier to gain access to the forest," said Paulo Barreto, an Imazon researcher. The recent numbers have spiked so quickly, he added, "it will be difficult for the annual figures to fall."
(Reporting by Paulo Prada. Editing by Todd Benson, Kieran Murray and Douglas Royalty)
Alister Doyle PlanetArk 24 Jan 13;
Greenland is less vulnerable than expected to a runaway melt that would drive up world sea levels, according to scientists who found that only a quarter of the ice sheet thawed in a warm period more than 100,000 years ago.
The study, involving 300 experts from 14 nations, implied that Antarctica at the other end of the planet would contribute at least as much or more to the kind of sea level rise that threatens coasts and cities from Mumbai to Miami.
Climate scientists are struggling to understand the risks of a melt of the vast ice stores of Greenland and Antarctica to help plan coastal protection. Sea levels rose about 17 cm (7 inches) in the past century and the rate has quickened.
Examination of ice from a 2.5 km (1.5 mile) deep ice core in northwest Greenland indicated that its ice sheet lost only about 400 meters (1,300 ft) in thickness in the early part of the Eemian, a warm period from about 130,000 to 115,000 years ago.
They estimated it lost about a quarter of its ice overall, according to a study published in Thursday's edition of the journal Nature.
"The volume of ice lost from the Greenland ice sheet was more moderate than many had expected," lead author Dorthe Dahl-Jensen, a professor at the University of Copenhagen, told Reuters.
Some past studies have suggested that Greenland may be poised for an irreversible melt due to climate change, blamed by a U.N. panel of experts on use of fossil fuels in nations led by China, the United States, India and Russia.
The limited size of the melt was also a surprise because the scientists found that Eemian temperatures, inferred from chemicals in air bubbles trapped in the ice, were higher than expected at 8 degrees Celsius (14 Fahrenheit) above current levels.
FOSSIL FUELS
"We'll probably reach the Eemian temperatures within the next 100 years," Dahl-Jensen said. The Arctic region is warming at one of the fastest rates on the planet; global warming of 2 or 3 degrees Celsius (3.6 to 5.4 F) might trigger an 8 degrees C rise in Greenland.
The United Nations panel of climate scientists has said that sea levels may rise by between 18 and 59 cm (7-24 inches) this century, or by more if a thaw of Greenland or Antarctica speeds up. Elsewhere, it expects more floods, droughts and heat waves.
And there are already signs of Eemian-style conditions. In July 2012, almost the entire surface of Greenland was covered in melt water, an event witnessed by the scientists from the United States, Canada, France, Germany, Britain, Japan, South Korea and elsewhere.
"It even rained in our camp," Dahl-Jensen said.
Ice cores build up from annual snowfall and can be read like tree rings to judge their age. The Eemian warmth was probably caused by natural shifts in the Earth's orbit around the sun.
The scientists estimated that Greenland contributed only about 2 meters to sea level rise of between 4 and 8 meters during the Eemian.
That meant that at least half and perhaps much more of the melt water came from Antarctica, the planet's other big store of land ice, which, unlike the floating ice of the Arctic, causes the sea level to rise when it melts.
As yet, there has been no study of cores from the crucial West Antarctic ice sheet equivalent to the Greenland research.
(Reporting by Alister Doyle, Environment Correspondent; Editing by Kevin Liffey)
Posts
visitors since Nov 07