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HK Told To Aim Low On Clean-air Targets Officials Advise Adopting WHO’s Guidelines

Cheung Chi-fai, SCMP – Updated on Mar 14, 2009

Hong Kong has been advised to adopt the minimum targets of World Health Organisation air quality guidelines, officials said yesterday.

They were unveiling the outcome of the air quality objectives review conducted by its consultant since June 2007. The review aimed to update the standards unchanged since 1987, with reference to the WHO guidelines issued in 2006.

Compliance with the WHO guidelines could cut hospital admissions caused by air pollution and increase the average Hongkonger’s lifespan by around nine hours, they said.

But the officials failed to offer either a timetable for meeting the targets or a road map for going beyond that, saying issues about the pace and willingness to pay for clean air measures would be left to the public to decide in a consultation later this year.

According to the review findings, Hong Kong should adopt the least stringent of the WHO’s three sets of guidelines for sulfur dioxide and ozone but relatively tougher limits for respirable suspended particles.

The consultant also proposed introducing a limit for fine particles known as PM2.5, which were believed to be more detrimental to health than heavier particles.

A total of 19 first-phase measures, including increasing the use of natural gas, were identified as helping to meet the new objectives. There were another 17 measures for longer-term targets.

Among these early measures, the most cost-effective was bus route-rationalisation. However, the early retirement of old diesel vehicles delivered most benefits.

The officials estimated that electricity charges would rise by 20 per cent if half of the city’s power was generated using natural gas. They also estimated that bus fares would increase by 15 per cent if all old buses were phased out.

However, a green group described the estimates as “scare tactics”, saying it was being used by the government to justify adoption of the least stringent of the WHO’s three sets of standards.


“The only purpose of these figures is to scare the public. But it has failed to take into account the health cost of pollution,” said Edward Chan Yue-fai, campaigner for Greenpeace.

Full compliance with the new objectives could save 4,000 hospital admissions a year. The estimated minimum cost of implementing the measures was around HK$28.5 billion.

A senior environment official yesterday declined to give an estimated time frame for meeting the objectives. The official said the pace, priority and price of the measures would be clearer after collecting views from a public forum on the review next Friday, and they would become the core questions in the final public consultation to be launched in the summer.

“The targets are ambitious and there is a lot of work to achieve them. But we will definitely speed them up,” the official said.

The official also said that no country had adopted the most stringent targets and it was believed a “progressive” approach towards meeting the long-term goals was more preferable.

The officials also warned that power plants might be unable to renew their licences while new infrastructure projects would not be able to go ahead if some unachievable targets became the criteria for environmental impact assessment.

They said “more radical measures” were required in both Hong Kong and Guangdong if the targets were to go beyond the proposed air quality objectives.

Hong Kong Air Pollution Rap by MC Yan

Wong Video Targets Wheezy City

Clara Mak – SCMP | Updated on Nov 08, 2008

Like a lot of people living in Hong Kong, Magic Boy director Adam Wong Sau-ping suffers bouts of hay fever. But instead of just blowing his nose into an endless number of hankies, he chose to address the issue of air pollution, which he believes triggers the reaction.

His concerns are probably justified. A recent Greenpeace report states that frequent exposure to air pollution can lower resistance to respiratory diseases and also increase chances of developing conditions such as asthma and bronchitis.

Greenpeace added that the Hong Kong government’s Air Pollution Index, its daily measure of air quality in the city, doesn’t quite reflect the reality. The index has been neither reviewed nor updated in the past two decades to match the World Health Organisation (WHO) standards, so Greenpeace has launched its own “Real Air Pollution Index”.

Meanwhile, Wong (pictured) filmed a short video to help promote the Greenpeace campaign. The 33-year-old recruited a group of children, whom he shot undertaking various activities around the city.

“At the beginning of the video, these 10 lovely children went out after they were reassured by the weather report that the air quality on the day was suitable for them to do outdoor activities,” he says. “So, they went out taking deep breaths in Kwun Tong, running in Sha Tin, blowing balloons in Central, playing music with a pianica and singing on the Tsing Ma Bridge.

“But by the end, you will hear these children coughing and wheezing because the current index just simply does not reflect the true air quality level here. We are using a standard that is some 20 years behind and far below the WHO standard,” Wong says.

Living in the busy district of Mong Kok, Wong has developed ways of dealing with air pollution. He takes a few steps back when he waits to cross the road to avoid breathing in fumes and he rinses his mouth with water when he gets home to prevent a sore throat.

Air pollution, he says, is as serious as the recent Chinese milk powder scare. “It’s like telling a child the milk he drinks is contaminated with melamine. The difference is if you don’t drink the milk every day or eat a large quantity of White Rabbit candies in one go, you probably won’t develop a kidney stone or die. However, you can’t choose not to breathe even though the air is polluted. It’s just scary.”

Wong tries to protect the environment by using fewer plastic bags and recycling plastic bottles. He says he was heavily influenced by Japanese animation master Hayao Miyazaki’s films which often touch on environmental subjects.

“One of his films, Nausicaa of The Valley Of The Wind [1984], talks about the friendship between an insect and a human. The eyes of the bug go red when it is angry and turn blue when the people are being friendly to it. It taught me the relationship between nature and human beings and how the two should live together peacefully.

“Besides, we are not here to conquer the world,” he says.

To watch Wong’s video and to learn more about the Real Air Pollution campaign, visit

Emissions At Least On Par With US: Beijing Admits It May Be World’s Top Polluter

Shi Jiangtao in Beijing – SCMP | Updated on Oct 30, 2008

A top climate official has admitted the mainland’s greenhouse gas emissions are at least on a par with those of the United States, but said the unfolding financial crisis was presenting new economic and technological opportunities to restructure the international campaign against global warming.

Xie Zhenhua , deputy director of the National Development and Reform Commission, also said yesterday rich countries must take the lead in cutting greenhouse gas emissions, and contributing money and technology to developing countries.

It was the first time the central government had publicly acknowledged that China may have passed the US to become the world’s biggest greenhouse gas emitter.

“Based on information we have at hand, our total emissions are roughly the same as the US,” Mr Xie said at the launch of the country’s first white paper on tackling climate change.

International research institutes and experts have said for two years that China’s output of carbon dioxide, the key greenhouse gas, had surpassed that of the US, given that the latest data on China’s greenhouse gas emissions was from 1994.

But Mr Xie said: “Whether or not we have surpassed the US is not in itself important.” He repeated China’s stance that it was only fair to consider historical and accumulated emissions in determining whether developed or developing countries should play a bigger role in the global fight against climate change.

The white paper says: “Developed countries should be responsible for their accumulative emissions and current high per capita emissions, and take the lead in reducing emissions, in addition to providing financial support and transferring technologies to developing countries.”

Mr Xie said China’s per-capita emissions for its 1.3 billion people remain much lower than those of rich countries, and was about a fifth of the US average. “As China is in the process of industrialisation and urbanisation, it is fairly natural that the country’s greenhouse gas emissions grow very fast,” he said.

He also said it was not fair for China to take responsibility for emissions generated on behalf of countries that consumed Chinese exports, which accounted for 24 per cent of the country’s total emissions.

Both the white paper and Mr Xie played down the growing criticism over China’s refusal to accept a mandatory target in cutting emissions.

“There is no doubt that under the Kyoto Protocol, developed countries must take the lead in reducing their greenhouse gas emissions,” Mr Xie said.

Under the UN-sponsored treaty, developing countries are not obliged to accept mandatory caps, but the US has refused to ratify it, citing the framework’s failure to hold China and India more responsible.

“But regardless of the results of international negotiations and how much developed countries honour their commitments, China from its own perspective must realise sustainable development,” Mr Xie said. “We must save energy, raise energy efficiency, develop renewable energies and adopt measures aimed at reducing greenhouse gases.”

He said the financial turmoil should be viewed as an opportunity for China as well as the whole world to carry out economic restructuring, promoting environmentally friendly technology and cutting pollution.

“Tackling climate change and the financial crisis is not contradictory,” he said. “We will seize the opportunity to increase domestic demand and funding on energy efficiency. We will have to solve climate change and environmental problems through development.”

Mr Xie said developed countries should contribute at least 0.7 per cent of their gross domestic products to help developing countries fight global warming.

Analysts said the release of the policy paper as well as recent remarks by mainland officials were part of Beijing’s strategy amid intense negotiations on a successor to the Kyoto Protocol, which expires in 2012.

An international climate change seminar on technology transfer organised by the UN and China will be held in Beijing next week, and delegates from more than 190 countries will participate in another key UN conference on climate change in Poznan, Poland, in December.

Yang Ailun , from Greenpeace China, said the white paper was basically a review of the government’s achievements in tackling climate change in the past few years.

“While it may not have much new information, it is clearly aimed at highlighting China’s progress in cutting emissions ahead of international negotiations,” she said.

Mong Kok Pollution ‘Three Times’ WHO Levels

Peter So – SCMP – Updated on Oct 01, 2008

A green group and legislator warned the worsening air quality at tourist spots would scare off visitors, and are urging government to tighten the air-quality measuring standards.

Greenpeace have conducted on-site monitoring of the levels of respiratory suspended particulates (PM-10) and fine suspended particulates (PM-2.5) on Monday and Tuesday this week – prior to the peak tourist period of “Golden Week” – in a pedestrian area of Mong Kok.

The experiment discovered that the concentration levels of both particulates had three times exceeded the World Health Organisation’s most stringent standards. It means tourists and local residents’ health could be threatened if they are exposed to the area for several hours.

Paul Tse Wai-chun, a legislator in the tourism sector, said the poor air quality would damage the city’s image in the long run.

An earlier survey found 48.8 per cent of local tourist guides had received complaints from tourists about the city’s air pollution, Greenpeace said.

Meanwhile, Mr Tse called on the government to amend the air-quality measuring standards in accord of the WHO guidelines which [were] established in 2006.

The current government standards had been adopted since 1987, and it did not include PM-2.5 – which research suggests can penetrate deep into human lungs and have more severe health effects than larger particulates.

“The current standards are too loose and outdated,” said Mr Tse.

He said it is the responsibility of the government to update the Environmental Protection Department’s Air Pollution Index to let the public know the real situation of air pollution.

Mr Tse added that initiatives to improve the “wall effect” created by high-rise buildings and the control of traffic flow in busy districts should be undertaken.

Despite the government would commission a study to review the air-quality objectives and development a long-term management strategy, Greenpeace campaigner Prentice Koo Wai-muk said the government has no time-table to amend current standards to meet the WHO’s more stringent standards progressively.

And the green group would update a “Real Air Pollution Index” on the website – – which would monitor air pollutants including sulphur dioxide, ozone, respirable suspended particles and nitrogen dioxide with the updated WHO standards.

Meanwhile, Greenpeace has made travel tips on the city’s scenic spots with better air quality to tourists. Mr Tse said the government can promote those spots as a remedy.

Hong Kong Choking On Its Own Pollution

Dirty old town

Hong Kong is slowly choking on its own pollution. Technology may be a major cause, but it could also be a cure

David Wilson – Updated on Sep 28, 2008 – SCMP

Hong Kong survived the bird-flu pandemic and Asian financial crisis in 1997 and the Sars outbreak in 2003. Now many fear that it will be a chronic crisis – air pollution – that will do most harm to the city’s future.

In a place where earnings and acquisition have long been people’s priorities, a dramatic shift in behaviour appears necessary to prevent Hong Kong from becoming a victim of its “toxic sewers”.

Calls have been made, urging consumers to adopt “clean” technologies, and the city’s government and commercial sectors to pursue more green initiatives.

Clean technology, as described by United States-based research firm Clean Edge, is “a diverse range of products, services and processes that harness renewable materials and energy sources, dramatically reduce the use of natural resources, and cut or eliminate emissions and wastes”. It notes that clean technologies “are competitive with, if not superior to, their conventional counterparts”.

Green initiatives include campaigns against “light pollution” – the excessive use of neon lights and overlit advertising. Government-led efforts include implementing strict guidelines for auditing the carbon emissions of commercial and residential buildings and more stringent air-quality, fuel and vehicle emission standards.

According to research conducted at the University of Hong Kong, the city’s air contains almost three times more soot and other pollutants than New York’s and more than twice that of London. Hong Kong is bedeviled by high particulate matter levels, which are linked to increased mortality risk. It also has high levels of sulphur dioxide, which has been linked to childhood respiratory disease.

The main culprits are coal-fired power plants, wasteful household consumption and traffic. It was reported that Hong Kong’s roads are the world’s most crowded, with almost 280 vehicles for every kilometre. Early this month, Greenpeace China unveiled its Real Air Pollution Index for Hong Kong, to spur the government to fall in line with World Health Organisation (WHO) guidelines. On the green group’s website, there is the Air Pollution Clock – a free download that counts the number of hours since July 1 this year that Hong Kong’s air has failed to reach WHO standards.

As well as discouraging tourists, the pollution is threatening Hong Kong’s status as Asia’s financial hub. US investment bank Merrill Lynch has warned that the air quality is so lousy it poses a real danger to the city’s long-term competitiveness. Already, multinational corporate executives have given up on Hong Kong’s smog-filled skyline and moved to greener Asian cities, such as Singapore. We have asked a group of local experts to share their views on how members of the community can do their bit to help clean up the city and the planet.

Christine Loh Kung-wai is a former Hong Kong legislator and chief executive of Civic Exchange, an independent, non-profit public policy think-tank.

“Anything that is more energy-efficient can qualify [as clean technology], including bicycles and other pedal-powered devices. Look at the Segway two-wheeled electric transporter. Consider low-energy light bulbs and lightweight hybrid cars such as the Hypercar from the Rocky Mountain Institute []. The vehicle offers ultra-light construction, low-drag design and hybrid-electric drive. Cars made with strong lightweight materials go further on less fuel.

“Then there is clean water technology – aided by devices such as filters and low-flow shower heads. More and more Escos [energy service companies], architects and engineers, even power companies are providing energy-efficient products.

“But changing our behaviour is more important than buying new technology. We must consume less.”

Christian Masset, chairman of Clear the Air (, a volunteer organisation targeting Hong Kong’s air-pollution issues, suggests that households take the initiative and provide a good example in their local communities.

“To save on energy, install a room temperature controller such as the ION Tx PIR. It’s basically a smart thermostat that controls the overall temperature using a network of occupancy sensors in various rooms in a home. It can be paired with the air conditioner or, even better, with less energy-consuming ceiling fans.

“Whatever electronics you have in your house, it’s best not to leave them on standby. Switch them off when not in use. This simple energy-cutting solution can save up to 20 per cent on your electricity bill.

“If you live in a windy location, install Motorwind [] turbines to produce part of your electricity without drawing it all from the [electricity] grid. The nylon turbines can be installed on balconies of flats or rooftops of buildings and generate electricity at wind speeds as low as 2 metres per second.

“For cleaner transport, I think people should support the Hong Kong-made electric car designed by EuAuto Technology []. All you need to do is plug the car into a standard household socket for six to eight hours to recharge its batteries. Once the vehicle has been fully charged, you’re ready to go – and at speeds of up to 40mph.”

James Ockenden, publisher of environmental technology, engineering and finance magazine Blue Skies China [], believes that prudent investment decisions could make a big difference.

“Buy a clean-tech mutual fund but watch where the money is invested. Some high-street `climate change’ funds invest in Toyota, claiming hybrid development is worthy of green money. That is debatable. Make sure the fund manager’s definition of `green’ aligns with yours. If you have US$50,000 to invest, consider a specialist Chinese venture capital fund. The money will go pretty much directly into a clean technology start-up.

“Watch your carbon offsets [a carbon offset is a financial instrument representing a reduction in greenhouse-gas emissions]. Choose a well-audited scheme such as [the non-profit US organisation buys and retires certified carbon offsets for its donors]. You can be sure your money will actually go towards making industry pay more for the right to produce carbon dioxide [CO2] emissions. A tonne of CO2 reduction costs from €20 [HK$230] to €30 in the European market, while some retail schemes charge 10 times that for questionable, even worthless, carbon certificates.

“Don’t pick up the IPO prospectus; try to read it online when possible. The Hong Kong stock exchange is experimenting with electronic market information. If successful, it could be applied to the Chinese stock markets, saving billions of pages of ink and paper each year.

“Ditch the car, get a trolley [to carry bulky goods]. The classic Hong Kong trolley, which costs HK$300 and up, is a remarkable piece of clean-tech engineering – it’s green like a bicycle, carries a decent payload and fits into a taxi for long trips.

“Until there’s a decent environmental building code in Hong Kong, you’ll be hard-pressed to find any energy efficiency benchmark to compare flats to. Still, it doesn’t hurt to ask property developers tough questions. Demand some kind of energy efficiency/social responsibility report when looking at new buildings. Ask if the property has single-glazed windows. Check if the building uses low-VOC [volatile organic compound] paint. Organic vapour from paint is a major cause of brown haze.”

Martin Williams (, a Hong Kong-based conservationist, photographer and writer, sees the internet helping more people live an eco-friendly life.

“Technology tends to go against green living. But using the internet, consumers can get better information than many so-called `green’ television documentaries provide. The Web also allows individuals to take some action. You can join discussions, participate in online campaigns and play a role in making grander changes than simply switching to long-life light bulbs in your home.

“Also important: switch off, reduce, reuse and recycle. Have hi-tech gizmos repaired as soon as possible, don’t just buy new ones for the sake of fashion. Modern condoms may not be thought of as clean technology, but with the planet’s resources already overstrained by the human population, green living also means not having loads of children; future generations must be given a chance of a better life.”

For more information about Hong Kong’s air, visit Take a look at the Air Pollution Clock – if you dare.

Greens Urge Pollution Shake-Up

Joyce Ng – Updated on Sep 12, 2008

Greens have urged the government to step up the tightening of air-quality measuring standards – along international guidelines – after records in the past two months show air quality remains unsatisfactory.

The administration said it had been carrying out a review and would finalise the new measuring standards next year.

Three Greenpeace members yesterday climbed to the top of an air-monitoring station in Central and unveiled banners urging the government to revise its standards to reflect those introduced by the World Health Organisation in 2006.

The group found that in the past two months there had been 44 days when at least one monitoring station had recorded 24-hour-average concentrations of particulate matter that exceeded the WHO standards.

On one day in August, concentrations surpassed WHO standards in all but one of the 14 monitoring stations. In Causeway Bay, the measurement was 1.86 times the standard, but the official index classified the area as only having a “medium to high” level of pollution.

“The government standard, established in 1987, is too loose and outdated, failing to reflect the truth and protect our health,” Greenpeace campaigner Prentice Koo Wai-muk said.

Mr Koo urged the government to monitor minute particulates, known as PM-2.5, which research suggests can penetrate deep into human lungs and have more severe health effects than larger particulates.

In June last year, the Environmental Protection Department commissioned a study to review the air- quality objectives and develop a long-term management strategy.

A spokesman said the study was expected to be completed by the end of this year, after which the department would launch a public consultation and finalise the standards. The study would make reference to the WHO guidelines.

The existing index is calculated with reference to seven pollutants, including sulfur dioxide, nitrogen dioxide, respirable suspended particulates, carbon monoxide and ozone.

The WHO has recommended interim targets for governments to meet the more stringent standards progressively.

Tighter Limits On Pollution Sought

Activists, citing ‘real’ air monitor, seek tighter limits on pollution

Yau Chui-yan – Updated on Sep 07, 2008

Green groups and medical academics in Hong Kong say it is time for the government to adopt World Health Organisation air-quality guidelines, with Greenpeace releasing a downloadable “Real Air Pollution Index” software “widget” based on the international recommendations.

The widget, for computer desktops, can be downloaded free from the environmental group’s website and provides instant updates of air-pollution levels according to the WHO standard.

Edward Chan Yue-fai, campaign manager of Greenpeace China, said it was important for the public not to be misled by the Environmental Protection Department’s Air Pollution Index (API).

“The API corresponds to air- quality objectives which have not been revised since 1987,” he said. “The standard is just too vague.”

University of Science and Technology atmospheric scientist Alexis Lau Kai-hon also called for a change.

“API is a tool to communicate with the public. If it fails to communicate with the public about the health risk, then it is time to consider a new standard,” Dr Lau said.

The API ranges from 0 to 500 and is divided into five bands according to the potential effects on health.

It is calculated by comparing the measured concentrations of major air pollutants with health-related air-quality objectives established under the Air Pollution Control Ordinance.

However, the API is out of kilter with the standards applied by the WHO’s guidelines.

There are times with low API readings when pollutant levels are much higher than the WHO’s recommended maximum intake.

For example, the API in Mong Kok at 5pm on August 4 was 30, but some pollutant levels were much higher than the WHO standard.

According to the Environmental Protection Department, no action needs to be taken when the API is 30, which is considered “medium” pollution.

But the actual level of respirable suspended particulates – particulate matter measuring less than 10 microns – was 14 per cent higher and the level of sulfur dioxide 33 per cent higher than in the WHO guidelines.

Long-term exposure to air with high concentrations of particulate matter is associated with a higher risk of mortality, while high levels of sulfur dioxide have been linked to childhood respiratory disease.

Most recreational runners in Hong Kong responding to questions on a popular running website recently said they would check smog levels before exercising but few said they looked at the API.

However, one runner said he called off runs if the API rose above 100.

Although no country strictly follows all the WHO guidelines, Anthony Hedley, professor of community medicine at the University of Hong Kong, said that was not an excuse for Hong Kong to avoid doing so.

“Hong Kong and the Pearl River Delta are among the most heavily polluted areas in the world,” he said. “Moreover, the WHO standard has embedded studies conducted in the Pearl River region; it is not something generated in another part of the world. There should be no excuse.”

The government replied that a study scheduled to be completed by the end of this year would recommend a new set of air-quality objectives and a corresponding long-term air-quality-management strategy for Hong Kong.

It said it would make reference to the WHO air-quality guidelines.

Support For Tree Preservation

Eva Wu – SCMP – Updated on Aug 30, 2008

Almost all would-be lawmakers say they support legislation aimed at preserving trees in the city.

Five green groups – the Conservancy Association, Friends of the Earth, Greenpeace, Green Power and Greeners Action – initiated a “green charter” this month and sought the support of all Legislative Council election candidates.

Replies from 44 of the 46 individual candidates or party tickets supported a call for a law preserving trees in the city that would comprehensively detail how they would be protected.

On Wednesday, a tree – which experts said could have been diseased for some time – collapsed at Stanley Market and killed a young woman. The accident raised concerns about the health of trees throughout the city.

Conservancy Association campaign manager Peter Li Siu-man said there might be some obstacles to legislation on the issue.

“The government would have to commit much more resources to preserving trees,” he said. “Once a law was passed, the government would be required to remedy cases of neglect.”

The charter, which contains 11 demands covering issues ranging from air pollution to conservation policies, received a cool response from trades-related candidates and business-affiliated political parties.

Of the 59 candidates standing in the 30 functional constituencies, only 10 signed the charter. Some said they needed more time to study it and others rejected it outright. Liberal Party candidates refused to sign it.

Mr Li said the response was disappointing. “Trees are a public concern, as everyone can see after the accident. Their response reflects how much they support conservation policies despite what appears on their platforms,” he said, adding that many platforms failed to meet the charter’s basic demands.

Greenpeace’s Edward Chan Yue-fai said voters should scrutinise the stance of candidates on environmental affairs.

Emissions Legislation Does Not Go Far Enough

Air pollution bill passes, but lawmakers are still unhappy

Emissions legislation does not go far enough, say critics

Cheung Chi-fai – Updated on Jul 11, 2008 – SCMP

Lawmakers yesterday endorsed cross-border emissions trading and gave legal backing to caps on power firms’ emissions of pollutants.

They demanded unanimously that officials set out a framework for handling the city’s “carbon footprint”, which was excluded from the measure passed yesterday because officials say they need more time.

The measure also spells out the way caps on emissions of three major air pollutants will be determined beyond 2010.

Cross-border emissions trading will give power firms leeway to meet emissions caps by means other than reducing the pollution their chimneys spew into the air.

A majority of lawmakers voted in favour of the Air Pollution Control (Amendment) Bill 2008.

However, the legislators were unhappy that it has not put Hong Kong’s efforts on a par with other countries in the fight against climate change.

“When is the government going to really take global warming seriously? Please stop telling us that the issues are being studied and instead give us a clear timetable and strategy,” said Audrey Eu Yuet-mee, the Civic Party leader.

Democrat Sin Chung-kai urged the government to table concrete initiatives in the next legislative term to keep Hong Kong ahead of other Chinese cities in curbing greenhouse gas emissions.

DAB legislator Choy So-yuk criticised the measures as inadequate and biased in favour of power producers. “It is just a little better than nothing,” she said.

She proposed an amendment to limit the validity of emissions-trading contracts to five years. While arguing her case, she appeared close to tears as she claimed an official, who she did not name, had made misleading comments about her proposal.

“There have been media reports quoting official sources saying the real motive of my proposal was for election purposes. This is complete nonsense and misleads the public,” she said.

Without a time limit, Ms Choy said, emissions trading would merely create a window for local power producers to emit excess pollutants indefinitely as long as they could buy sufficient quota from mainland counterparts to cover the extra pollution.

Fellow lawmakers rejected her proposal. They preferred a government proposal to limit power firms to buying quotas equal to a maximum of 15 per cent of their annual pollution caps. Environment minister Edward Yau Tang-wah said Ms Choy’s proposal would reduce power producers’ flexibility to trade quotas.

As for the city’s carbon footprint – the measure of the carbon emissions all economic and human activity generates – Mr Yau said the administration was serious about taking action, but reducing it would require a significant adjustment to power producers’ fuel mix.

The Legco meeting was interrupted when two Greenpeace protesters in the public gallery held up a banner labelling the environment minister an “accomplice to global warming”.