Best of our wild blogs: 14 Jun 12

Piece of croack
from The annotated budak

Boggled by bivalves? Come for the Bivalve Workshop 23-27 Jul
from wild shores of singapore

The Semakau Book is launched!
from wild shores of singapore

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New cable car system will ease Sentosa congestion

It may even be an attraction in itself, say tourism experts
Jessica Lim Straits Times 14 Jun 12;

A NEW cable car system in Sentosa will help ease congestion on the island and may even become a tourist attraction in its own right, say travel agents and tour guides.

Sentosa Development Corporation, which manages the island, has not decided if it will charge for rides on the new intra-island transport system to be built by 2015.

Rides on the monorail and buses within the island are free.

"Sentosa has become more crowded over the years and sometimes the roads are quite congested," said Ms Alicia Seah, CTC Travel?s senior vice-president for marketing and public relations.

"With more connections between attractions, people will be more open to the idea of leaving their cars at home. It may also become a tourist attraction in itself," she said, adding that cities like Sydney also have cable-car rides within major tourist attractions.

Tour guide M. Loganathan, 52, who takes one tour group to Sentosa a week, said there is often a bottleneck at certain venues on the island.

He and his group have to wait about 10 minutes to exit the coach bay after popular shows like Songs Of The Sea end in the evenings.

"Things will just get worse when more people come," he said, noting that Sentosa is already experiencing a surge in visitor numbers.

"This also opens up the possibility for us to drop tourists off at a cable-car station and then let them take a ride to the attraction," he added. "This way, the coach doesn't have to move around on the island at all."

Currently, private vehicles, coaches and taxis account for 56 per cent of inbound arrivals while the monorail, cable car from Mount Faber and boardwalk make up the rest.

Industry watchers like Ngee Ann Polytechnic senior lecturer in tourism Michael Chiam said the new system would help to ease congestion at the three areas where the stations will be located - Merlion Plaza, Imbiah Lookout and Siloso Point.

The new cable system will also help rejuvenate the island and preserve its allure as a tourist destination.

Said Mr Chiam: "Tourist attractions like Sentosa need to constantly stay attractive and renew themselves to attract repeat visitors."

Sentosa, which opened as an island resort in 1972, turns 40 this year.

To celebrate, Singaporeans born in 1972 will be given free island admission via the Sentosa Express monorail and Sentosa Boardwalk in August and September.

Sentosa to build new cable car line
Jessica Lim Straits Times 14 Jun 12;

SENTOSA is rolling out another cable car service in 2015 to make it easier for the growing number of visitors to get around the island.

The 860m-long link - half the length of the current cableway linking Sentosa to Mount Faber - will transport visitors within the island between the three main clusters of attractions at Merlion Plaza, Imbiah Lookout and Siloso Point.

The new line will be able to hold up to 38 cabins.

The current three-station link, at 1.72km, holds 68. It was opened in 1974, but has been upgraded four times since.

The shape and design of the cabins have yet to be determined, but they will seat eight passengers each and be enclosed, not unlike those in the current system.

Work is expected to start next year and be completed by 2015.

Sentosa Development Corporation (SDC), which manages the island, is unable to reveal the cost as the tender, which closed recently, has not been awarded to a contractor yet.

The new three-station transport link will complement the current free intra-island monorail and bus service. The system will help handle the surge in visitor numbers, said SDC.

By the end of the month, the island will welcome its 150 millionth guest since it first opened as an island resort in 1972.

Numbers have jumped from 6.2 million in 2009 to 19 million last year, on the back of the opening of Resorts World Sentosa and Universal Studios theme park.

Even more visitors are expected in the next few years, with the opening of attractions like KidZania - Singapore's first theme park targeted at children - in 2014.

SDC chief executive Mike Barclay said the cableway will be a key addition to the island's transport network and will help meet Sentosa's future transport demand.

'The aim is for guests to spend as little time as possible in queue lines while they move about the island,' he said, noting that the highest point of the cableway will be 80m above sea level.

The new system will be able to move about 1,600 people per hour in one direction.

The waiting times will also be shorter - 18 seconds, compared with the three minutes for the monorail and 15 minutes for the bus.

The current cable car system - operated by Mount Faber Leisure Group, a fully owned subsidiary of SDC - goes up to 120m above sea level at its highest point, to allow ships to pass under it.

It has a capacity of 2,000 guests per hour per direction, while the monorail can take up to 4,000 guests per hour per direction.

SDC will issue a tender for building the stations soon and has not ruled out extending the system to the rest of the island.

The idea of building a cable car system on the island itself was first mooted in 2009, when SDC conducted a feasibility study on the project.

The new system is part of the statutory board's $250 million transport plan, which included the Sentosa Boardwalk that opened early last year.

By 2015, a road tunnel by the Land Transport Authority - connecting outbound traffic from Sentosa to Kampong Bahru and Keppel roads - is also expected to be ready.

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Shark's fin: Different findings on mercury

Straits Times Forum 14 Jun 12;

BEING at the apex of the food chain, sharks accumulate vast amounts of toxic materials that have either been washed into the oceans or dumped there by man.

As confirmed by Singapore's Agri-Food & Veterinary Authority (AVA), the bulk of toxic materials is found in fish muscle ('Shark's fin not 'impregnated with mercury' ' by Mr Tan Keng Tat; last Saturday).

Nevertheless, no organ is spared, even if some selectively accumulate more toxins than others.

We cannot get too little of a bad thing, especially considering how little nutrient or nourishment value there is in shark's fin.

In contrast to the AVA's findings, in 2001, 70 per cent of shark's fin samples sent by conservation group WildAid to the Thailand Institute of Scientific and Technological Research were found to have extremely high levels of mercury.

The discrepancy between this finding and the AVA's was explained thus: The Thai shark's fin samples were imported from Hong Kong, whereas Singapore gets shark's fin from more than 20 countries, of which only 10 per cent come from Hong Kong and 1.4 per cent from Thailand.

This begs the following questions: Do sharks respect national borders? More importantly, do shark's fin aficionados inquire about the provenance of the shark cartilage they are devouring? And in the interim period of the last 11 years, just how has the situation evolved?

It would be edifying to get some answers from the AVA.

Dr Yik Keng Yeong

Shark's fin not 'impregnated with mercury'
Straits Times Forum 9 Jun 12;

DR YIK Keng Yeong's claim that shark's fin is 'impregnated with mercury, a neurotoxin' has no merit ('Shark's fin delight: The end doesn't justify the means'; Thursday).

The Agri-Food & Veterinary Authority (AVA) found that 'tests done on the shark's fin products have shown that mercury was either not detected or was at levels well below the permitted level of five parts per million' ('Products sold in Singapore 'safe''; July 5, 2001).

According to the AVA, the toxic mercury is found mainly in fish muscles, and there is very little muscle in shark's fin.

This was corroborated by the United States Food and Drug Administration, which warned that eating shark meat may expose people to potentially dangerous, high levels of mercury.

And new research done at Rutgers University in 2010 showed that mercury levels are even higher in some species of tuna like the bluefin, bigeye and yellowfin - levels that exceed or approach those permissible by Canada, the European Union, Japan, the US and the World Health Organisation.

Millions of sharks will continue to be caught unintentionally in longlines and killed by the industrial-scale fisheries in the West, unless legislation is in place to regulate them. And millions more will be served up in fish and chip dishes in the US and EU, even if we stop eating shark's fin soup.

Tan Keng Tat

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NTU researchers studying structure of mantis shrimp claw

Sharon See Channel NewsAsia 13 Jun 12;

SINGAPORE: The mantis shrimp may look like a lobster, but one weapon it has sets it apart from its cousins.

Its claw is capable of unleashing a force of more than 50 kilogrammes, which is a hundred times its own weight.

And researchers at the Nanyang Technological University are on their way to finding out the secret behind this weapon.

They have generally divided it into three components - a common bone material found in humans, calcium carbonate which is commonly found in shell fish and chitin, which is a natural polymer fibre that resembles cellulose in plants.

Assistant Professor Ali Miserez, who is from the School of Materials Science and Engineering at Nanyang Technological University, said: "There is a combination of factors but mostly, it's the fact that you have a building block which is arranged together in a very specific manner. If you take each individual building block, it is not that impressive actually. What makes it very unique is how the blocks, the minerals and the natural polymer are arranged together and form the entire structure."

This unique structure allows the mantis shrimp to smash its prey without damaging its own claw.

The next step is to better understand how the components can be put together so that the material can be replicated in the lab.

Asst Prof Miserez said: "We can use the exact same component... and try to reorganise it at the nanoscale. The other thing is we can actually use the concept and design that we see in the structure so that we can have different materials and try to arrange them in the same way that we see in these natural materials."

It may take five to 10 years before the structure of the mantis shrimp club can be replicated but Asst Prof Miserez believes there are many potential biomedical uses for such a tough material.

"If we can fully mimic this, we can make new implants that don't suffer wear and damage. For instance, an artificial hip will wear off over time. With this system, we could prevent abrasion. That will be a huge breakthrough because this is a big problem with biomedical and orthopaedic implants."

He added the material may potentially be used to make bullet-proof vests or even aircraft components.

- CNA/fa

Shrimp power to boost medical implants
Straits Times 15 Jun 12;

THE Mantis shrimp may weigh 400g on average but it can knock out prey with force and at great speed.

A research team's finding of why the creature's 'arms' can withstand impact and abrasion could now be applied to making medical implants that are lighter and up to 500 times stronger than existing models.

Assistant Professor Ali Miserez from Nanyang Technological University's (NTU) School of Materials Science and Engineering and its School of Biological Sciences, his PhD student Shahrouz Amini and Harvard University's Dr James Weaver collaborated on the study of the shrimps' dactyl clubs.

These 'arms' allow it to generate a force exceeding 500 newtons and strike prey in 2.7 milliseconds, 37 times faster than the blink of an eye.

The team discovered that each club comprises many alternating stiff and flexible layers in a spiral structure. This highly damage-resistant property could prove useful in medical products like hip and joint implants, where the wear and tear of metal components may cause complications.

The team will now focus on developing a new bio-compatible material which would reduce known risks associated with these implants, like bone loss and disability.

Said Prof Miserez: 'Using a nature-inspired blueprint to design biocompatible implants is actually a 'shrimple' solution.'

The new material is expected to be lighter and more impact-resistant than existing products.

It could also be used in military armour, vehicles and aircraft components.

Prof Miserez said: 'I want to inspire young people to take up science research, by giving them a chance to participate in cutting-edge research, just like how I was inspired by my professors when I was a student.'

SHERRI LEE

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Malaysia: The Pengerang story

My Sin Chew 1 Jun 12;

With the petrochemical complex of Petronas now in the active phase of development and with the Kuokuang petrochemical hub project in the pipeline, public outcry continues to be heard.

Pengerang-born chairman of JB Newspaper Distributors Association Mr Zhu Suiling told me, "I'm afraid my hometown will soon become uninhabitable."

I was not able to see the fury planted deep inside his heart, but from his face I could perceive a deep sense of melancholy.

His narration just yesterday morning transported me back in time to the rustic fishing village of his childhood.

In late 1940, Zhu, a 10-year-old boy then, woke up about seven every morning, and later walked with seven or eight companions to school from his house.

The almost 1-hour journey was made along an extended stretch of white sandy beach bisected by a stream where the boys had to take off their shoes and wade cautiously across the water with their shoes in their hands, watching out for the crocodiles rumoured to be present in the water.

Zhu said he could not forget the turtle egg-laying season, when one or two giant sea turtles could be spotted laying eggs on the quiet beach as the first ray of sunlight broke the darkened sky.

"We were still very young at that time, knowing nothing about the need to protect the endangered species. Sometimes we would dash forward and mischievously turn the turtles on their backs, and laughed our way home.

"By the time we finished school at five, the tortured turtles had died, and again we yelled jubilantly and tossed the dead reptiles into the boundless sea.

"Sometimes we would catch little crabs on the beach, or played with turtle eggs as if they were footballs."

Zhu recalled that the Japanese troops built a trunk road and a rail line across Pengerang during the Occupation, and started mining for aluminium. However, the Japs surrendered before they could even afford to freight away the ore.

Zhu could not quite remember when aluminium mining operations were revived after the war, but he could remember very well that the water which had been used to rinse the ore was drained straight into the sea, contaminating the giant sea turtles' habitat. Before long, sea turtles were out of sight on the beach of Pengerang.

"Later, probably because of a government directive, the water used to rinse the ore was diverted to a nearby low-lying swamp, and very soon the trees there were all killed.

"No one knew anything about environmental preservation back in those years. We didn't know how to protect. We only had to accept things quietly and in resignation."

To older generation of Pengerang residents like Zhu, what is closest to their hearts is an inborn affinity to their homeland.

Time has changed. What young Malaysians today want is a green home. They won't keep their mouths shut like their fathers and grandfathers. They insist on their entitlement, and would fight to this end.

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Indonesia: Aceh Peat Clearing Was ‘Illegal’

Fidelis E. Satriastanti Jakarta Globe 13 Jun 12;

A formal government investigation into the clearing of a vast tract of protected peat forest in Aceh has concluded that only one of the two companies involved was at fault, while exonerating a second company of any wrongdoing.

Sudariyono, the deputy for legal compliance at the Environment Ministry, said on Monday that palm oil plantation company Surya Panen Subur 2 “was suspected of burning some 1,183 hectares” of land inside the Tripa peat swamp from March 19 to 24 this year.

“Our suspicion is that a really wide swath of land [was burned] in such a short time, and this indicates that it was systematic, meaning there was an element of intent,” he said.

He added that a second company, Kallista Alam, was believed to have burned some 30 hectares of its 1,605-hectare concession in the peat swamp, but that it was the victim of a bureaucratic foul-up.

“Its permit is suspected to be the problem, because it was issued after the [deforestation] moratorium was implemented,” Sudariyono said.

He added that while the law prohibited the issuance of new concessions on land with peat layers more than three meters deep, the two companies were given concessions for just such an area.

Kallista’s permit, issued by former Aceh Governor Irwandi Yusuf, is currently the subject of a legal challenge by activists, who point out that it was granted after a moratorium map was published that clearly identified Tripa as a protected area.

The Tripa swamp is a key habitat of the Sumatran orangutan, a critically endangered species, with 200 individuals believed to be living in the area.

Sudariyono said the ministry’s investigation team had not found any indications that orangutans might have been killed in the forest fires.

“We have not found any orangutans in the cleared areas, possibly because they ran away,” he said.

Basuki Wasis, a forestry expert from the Bogor Institute of Agriculture (IPB), also said there were no indications of any orangutans being killed.

“However, there were six orangutans captured by an NGO, the Leuser Ecosystem Foundation,” he said.

“Four of them have been returned to the forest, while the rest are now at the local nature conservation office.”

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Culling bats does not halt rabies, says report

Mark Kinver BBC News 13 Jun 12;
Common vampire bat caught in a net, Brazil (Image: AP) Common vampire bats are a natural reservoir for the rabies virus

Culling vampire bats in South American nations does not curb the spread of rabies, in fact it could actually be counterproductive, a study suggests.

Until now, it had been assumed that controlling bat numbers would, in turn, control the spread of the rabies virus.

Researchers say rabies is found in most bat populations, but vampire bats - which feed on mammals' blood - are responsible for most infections.

The findings have been published in the Proceedings of the Royal Society B.

"We found that rabies is there no matter what," said co-author Daniel Streicker, an ecologist at the University of Georgia, US.

"The size of the bat colony didn't predict the proportion of bats that were exposed to the virus.

"That's important because if there is no relationship between bat population density and rabies, then reducing the bat population won't reduce rabies transmission within bats."

For about three decades, the main focus in Peru to halt the spread of the virus - which is transmitted from animals to humans or livestock, and results in death if left untreated - has been to cull common vampire bats (Desmodus rotundus) using poisons, or even explosives.

The researchers, writing in their paper, explained that the data they collected over a 40-month period from 20 sampling sites revealed that culling was not having the desired effect.

In fact, Dr Streicker explained, the findings suggested that culling had a potentially counterproductive impact.

"In areas that were sporadically culled during the course of the study, we saw an increase in the proportion of bats exposed to rabies," he said.

Colonies that were frequently culled had slightly lower rates, the study showed, yet the ones that had never been culled had the lowest rates of all.

It is suggested that increasing levels of human encroachment into areas with vampire bat populations has exacerbated the problem.

Dr Streicker and the team said the study would continue for another two years, with the goal of developing a scientific-based solution.

The researchers hope the findings will help deliver a more effective method to protect public health and agricultural interests from the virus.

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EU fish discard ban agreed -- for 2019

AFP Yahoo News 13 Jun 12;

After 20 hours of talks into the early hours Wednesday, Europe's fisheries ministers finally struck a compromise deal to save the oceans from overfishing -- but failed to satisfy environmentalists.

The deal for a 2014 reform of the Common Fisheries Policy notably will ban the contested practice of discarding dead fish caught by accident, however not before 2019.

Ministers agreed that the European Union, the world's third fishing power, would tackle the problem of shrinking fish stocks in its oceans by limiting over-fishing by 2015 for some stocks, and 2020 at the latest.

Scientists say 80 percent of Mediterranean stocks are overfished -- meaning fish cannot reproduce quickly enough -- although the situation has improved in Atlantic waters.

Though the deal outraged environmentalists as too little too late, the EU's Fisheries Commissioner Maria Damanaki, who had lobbied for more far-reaching reform, welcomed backing for "a real discard ban with clear end dates".

She also said the ministers made "a real step forward" by endorsing proposals to set so-called Maximum Sustainable Yields (MSY) -- the maximum amount of fish that can be caught without compromising ability to reproduce.

"These are great achievements," she said while adding that "it is a fact that the Commission proposal is more ambitious".

Damanaki, along with green groups, urged the European parliament to toughen up the ministerial compromise when the accord comes before it for debate.

"Governments choose to perpetrate the status quo, wasting the once-in-a-decade opportunity to put the fisheries sector on the road to recovery," said the World Wildlife Fund. "We call on MEPs to keep working towards sustainable fisheries."

Dubbing the deal "highly disappointing", Ocean protection group Oceana said "ministers did not question the need to change fisheries management, they just admitted they are not ready to do it now.

"It is now up to the parliament to lead and make the necessary and immediate changes required."

Environmental groups say discards waste 1.3 million tonnes of fish a year and wanted an immediate ban on the practice.

Britain, Germany, the Netherlands and Scandinavian nations favoured forcing fishermen to bring all catches to port and deduct discards from their quotas.

But France and Spain notably argued for a "realistic, progressive" ban.

The ministers also ditched the Commission's proposal to stop subsidies to the fishing fleet by 2013.

The Netherlands and Sweden were unhappy with the final outcome, saying it failed to protect the oceans while Malta, Portugal and Slovenia thought it too pro-environmental.

Britain and France deemed the compromise a step in the right direction.

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Rio summit exposes grim Guanabara Bay

Vitoria Velez (AFP) Google News 13 Jun 12;

RIO DE JANEIRO — At the 1992 Earth Summit a grand plan was drawn up to tackle pollution in Rio's Guanabara Bay, but 20 years on the once-pristine fishing ground is a cesspool of garbage and toxic waste.

Guanabara at one time had healthy mangroves, sandy beaches and a rich ecosystem, but decades of urbanization and deforestation have taken their toll on waters now choked full of household garbage and sewage.

Fishermen blame the dwindling fish stocks on a massive oil leak in 2000, which saw nearly one million litres of crude spew into the bay from an underwater Petrobras pipeline.

"In the past, a day of fishing would bring 300 kilograms (660 pounds) of fish and between $40 and $50," 62-year-old fisherman Milton Mascarenhas Filho told AFP.

"Today, we get 30 kilograms and between $5 and $10 dollars," said Filho, president of the fishermen's association in Mage, a town on the northern shore of the massive bay, which runs past Rio de Janeiro to the sea.

A $1 billion program to depollute the bay was launched at the 1992 Earth Summit with funding from the Inter-American Development Bank (IADB), Japan's International Cooperation Agency and the Rio state government.

But 20 years later, there is little to show for it.

"It was the biggest clean-up program ever undertaken in Rio state but many mistakes were made and a great deal of the works have not been completed," local government official Gerson Serva told AFP.

-- Landfill and oil leak --

Ahead of the June 20-22 Rio+20 summit, which seeks to build on the Earth Summit 20 years on, Brazilian authorities have closed one of the more blatant symbols of the bay's degradation -- the Jardim Gramacho landfill.

Set up on ecologically sensitive wetlands 34 years ago, the seaside mountain of malodorous trash that saw some 8,000 tons of waste processed every day was one of the biggest landfills in the world.

Environmentalists had been crusading for its closure for years, blaming poor waste management at the site for much of the toxic leakage into the bay.

But it is the 2000 oil leak from a refinery belonging to state-owned energy giant Petrobras that experts believe is most responsible for the contamination that ruined the bay.

Petrobras, which was fined $28 million for the disastrous leak of some 338,000 gallons of crude, has spent more than $200 million over the past decade on environmental and social projects in the area.

Cruising through the bay reveals a startling amount of floating detritus. Clothes, shoes, sofas and television sets can be found bobbing along in the mangrove swamps hugging its shores.

"Guanabara Bay is today a huge cesspool and garbage dump," biologist Mario Moscatelli who has been leading the fight to clean up pollution in Rio state since 1997, told AFP.

Serva explained that some 15 municipalities in the area are criss-crossed by rivers that dump 20,000 liters of wastewater per second into the bay.

Of this total, only a third is treated and only 10 percent of the rest goes trough a natural process of decomposition.

-- Progress can be made --

State authorities recently signed a new, $640 million contract with the IADB to build and develop sewage networks in towns around the bay.

Moscatelli said it would take two decades to clean up Guanabara, even if short-term actions are already showing some results.

The "Living Mangrove" project, set up in Mage 12 years ago, shows that it is possible for the ecosystem to recover.

Run by the non-governmental group Onda Azul, it has used reforestation to turn an area of 1.6 square kilometers (0.62 square miles) into an ecological park.

A system was created to protect young mangrove seedlings with plastic bottles that are only removed when the trees are strong enough to cope for themselves.

Nearly 120,000 square meters (1.3 million square feet) of ground has been replanted and a second area of 160,000 square meters has seen 40 percent of its vegetation restored.

"The mangrove is a real marine cradle," Adeimantus da Silva, one of the project's authors, told AFP.

"We have recorded many birds, mammals and reptiles. Several fish species and 70 percent of crabs are already reproducing in the restored mangrove."

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Walking the Line: How to Identify Safe Limits for Human Impacts on the Planet

Should planetary limits on the alteration of critical environmental systems be used as guidelines for human activity?
David Biello Scientific American 13 Jun 12;

Is preserving the general environmental conditions that allowed civilization to flourish—a moderate climate, a rich array of species, rivers that reach the sea—necessary to ensure humanity endures? Or is minimizing alterations to the global environment introduced by human activity—rising levels of CO2 from fossil-fuel burning, widespread extinction, dams that impound water—more important to our success? Choosing the right approach is vital as the scale of human impact on the planet becomes so large that scientists are calling this new epoch in Earth's history the Anthropocene (when human activity alters global climate and ecosystems).

One bid for preservation initiated in 2009 by 29 scientists from around the world focused on the concept of planetary boundaries. They identified 10 environmental limits we might not want to transgress in the Anthropocene: aerosol pollution; biodiversity loss; chemical pollution; climate change; freshwater use; changes in land use (forests to fields, for example); nitrogen and phosphorus cycles; ocean acidity; and the ozone hole. That meme has now spread to the United Nations, and is driving ongoing global talks to address environmental problems, including the much-anticipated Rio+20 summit meeting that begins next week in Rio de Janeiro.

But a new analysis from environmental policy think tank the Breakthrough Institute released June 12 argues that such a focus on environmental restoration is actually counterproductive when it comes to overall human welfare. "The planetary boundaries framework is not a useful guide for policy or environmental management in any concrete sense, as it does not capture the challenges involved in most of the environmental problems it lists," argues geographer Linus Blomqvist, policy associate at the institute's Conservation Program and co-author of the review. "They should be discarded."

Specifically, Blomqvist and his colleagues argue that six of the 10 boundaries—land use, biodiversity, nitrogen cycle, freshwater use, aerosol and chemical pollution—do not have a hard limit at planet-scale physical thresholds that, if transgressed, would tip them into functioning differently. For example, managing a given watershed may make more sense than managing the amount of global freshwater consumption to stay below an arbitrary, sustainable "limit" of 4,000 cubic kilometers per year.

Further, breaking any of these boundaries might not have any negative impact on humanity. Indeed, cutting back on, say, nitrogen fertilizer could significantly set back human welfare given that more than half of the people on the planet are fed by food grown with synthetic fertilizer. A pristine rainforest, after all, provides less direct benefit to humanity than additional food production. Instead, society should focus on environmental trade-offs, the review argues. "The real limitations for sustainability are rather our ability to grow enough food, maintain a healthy climate and so on," Blomqvist says, although the analysis fails to offer its own limits or policy suggestions other than focusing more on climate change.

Reducing the emissions of the greenhouse gases that cause global warming makes the most sense in the context of planetary boundaries, and many of the other thresholds collapse into it, Blomqvist and his colleagues note. That makes climate change the defining boundary of the Anthropocene. "Arguably, the single most important measure to ensure climate stability is reform of our energy and transport systems," Blomqvist says. "There is every reason to regard the Holocene climate as desirable." (The Holocene epoch extends from about 12,000 years ago to the present.)

Although the 2009 study's authors also noted no thresholds exist for some of their planetary boundaries they proposed limits on land-use change, freshwater, nutrients and biodiversity based on two criteria. First, they help determine the resilience of ecosystems on land and at sea, which in turn impact whether larger boundaries, such as climate change, are transgressed. Second, they are associated with tipping points at the local scale. After all, when a large enough number of local ecosystems transform, a global shift occurs, notes Johan Rockström, one of the authors of the planetary boundaries concept and a natural resource management professor at Stockholm University.

"It would be good to define planetary boundaries at multiple scales—local, regional and global," adds ecologist Jonathan Foley, director of the Institute on the Environment at the University of Minnesota and a co-author of the planetary boundaries concept. But "if there are major changes in the global environment, beyond what we have experienced in the Holocene, then this could represent a serious disruption to our civilization."

Many of the criticisms offered by the Breakthrough Institute were raised in the original paper that presented the planetary boundaries concept, published in Nature on September 24, 2009. (Scientific American is part of Nature Publishing Group.) Blomqvist concedes that point, yet he says: "Given the sometimes naive reception of the [planetary boundaries] concept, we thought it was worthwhile pointing out."

Other scientists have criticized the planetary boundaries as too generous (for example, allowing too much human appropriation of freshwater flows) or employing the wrong metric (atmospheric concentrations of CO2 rather than cumulative emissions of greenhouse gases).

At the same time any effort to identify a safe operating space for humanity must grapple with the fact that humans, on the whole, have never been better off—whether the metric be population, wealth or some other measure. Any ecological degradation has not led to a collapse in human welfare.

The point of the planetary boundaries, according to its authors, is to enable an enduring human prosperity that doesn't destroy the planet's natural resources in the process—ultimately undercutting that good fortune. After all, the present wealth and attendant short-term boost in population, consumption and technological growth may be largely founded on longer-term deterioration of the planet, including declining fish populations, acidifying oceans, degrading soils, remnant forests, polluting watersheds and a transforming climate. "Future generations will pay the price for this," Foley argues, unless human activity is redirected. "I'm still hopeful that we can do this, but it will represent a massive shift from our current way of running the world."

Blomqvist agrees: "We must not destroy the ability of future generations to enjoy a healthy, good life by depleting resources for short-term gain." In addition, he says, "humans everywhere want food as well as beautiful landscapes and a rich biological heritage."

The difference in approach comes down to how best to manage the Anthropocene: through planetary boundaries suggested by the environmental systems that allowed the epoch to come about or through local or regional efforts aimed at weighing the complex trade-offs among human resource use, ecological needs and a global push to combat climate change. "Arbitrary boundaries are not helpful and, if anything, can be dangerously misleading on local and regional levels," Blomqvist maintains. And "critical transitions" or "tipping points" as suggested by the planetary boundaries concept may not exist for many of the cases because those shifts, if they exist, have already happened. "Earth has already been fundamentally and thoroughly transformed by humans," Blomqvist notes. "Saying that land-use change has a tipping point in this respect is like saying that there's a tipping point for methane-farting cows."

But now that planetary management is no longer a luxury but a necessity, many policymakers, including some of the nations gathering in Rio this month, have adopted the 10 boundaries as their negotiating framework. That suggests that such planetary lines in the sand are of at least some utility, although researchers will continue to revise them in a bid to help create an enduring home for humanity. "I see it as a useful framework for dealing with the complexities of managing the planet," Foley says. "We will see how the ideas are useful—or not—in the coming weeks and months."

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