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March, 2013:

A sensitive matter

30 March 2013

A sensitive matter

The climate may be heating up less in response to greenhouse-gas emissions than was once thought. But that does not mean the problem is going away

The Economist

OVER the past 15 years air temperatures at the Earth’s surface have been flat while greenhouse-gas emissions have continued to soar. The world added roughly 100 billion tonnes of carbon to the atmosphere between 2000 and 2010. That is about a quarter of all the CO put there by humanity since 1750. And yet, as James Hansen, the head of NASA’s Goddard Institute for Space Studies, observes, “the five-year mean global temperature has been flat for a decade.”

Temperatures fluctuate over short periods, but this lack of new warming is a surprise. Ed Hawkins, of the University of Reading, in Britain, points out that surface temperatures since 2005 are already at the low end of the range of projections derived from 20 climate models (see chart 1). If they remain flat, they will fall outside the models’ range within a few years.

The mismatch between rising greenhouse-gas emissions and not-rising temperatures is among the biggest puzzles in climate science just now. It does not mean global warming is a delusion. Flat though they are, temperatures in the first decade of the 21st century remain almost 1°C above their level in the first decade of the 20th. But the puzzle does need explaining.

The mismatch might mean that—for some unexplained reason—there has been a temporary lag between more carbon dioxide and higher temperatures in 2000-10. Or it might be that the 1990s, when temperatures were rising fast, was the anomalous period. Or, as an increasing body of research is suggesting, it may be that the climate is responding to higher concentrations of carbon dioxide in ways that had not been properly understood before. This possibility, if true, could have profound significance both for climate science and for environmental and social policy.

The insensitive planet

The term scientists use to describe the way the climate reacts to changes in carbon-dioxide levels is “climate sensitivity”. This is usually defined as how much hotter the Earth will get for each doubling of CO concentrations. So-called equilibrium sensitivity, the commonest measure, refers to the temperature rise after allowing all feedback mechanisms to work (but without accounting for changes in vegetation and ice sheets).

Carbon dioxide itself absorbs infra-red at a consistent rate. For each doubling of CO levels you get roughly 1°C of warming. A rise in concentrations from preindustrial levels of 280 parts per million (ppm) to 560ppm would thus warm the Earth by 1°C. If that were all there was to worry about, there would, as it were, be nothing to worry about. A 1°C rise could be shrugged off. But things are not that simple, for two reasons. One is that rising CO levels directly influence phenomena such as the amount of water vapour (also a greenhouse gas) and clouds that amplify or diminish the temperature rise. This affects equilibrium sensitivity directly, meaning doubling carbon concentrations would produce more than a 1°C rise in temperature. The second is that other things, such as adding soot and other aerosols to the atmosphere, add to or subtract from the effect of CO. All serious climate scientists agree on these two lines of reasoning. But they disagree on the size of the change that is predicted.

The Intergovernmental Panel on Climate Change (IPCC), which embodies the mainstream of climate science, reckons the answer is about 3°C, plus or minus a degree or so. In its most recent assessment (in 2007), it wrote that “the equilibrium climate sensitivity…is likely to be in the range 2°C to 4.5°C with a best estimate of about 3°C and is very unlikely to be less than 1.5°C. Values higher than 4.5°C cannot be excluded.” The IPCC’s next assessment is due in September. A draft version was recently leaked. It gave the same range of likely outcomes and added an upper limit of sensitivity of 6°C to 7°C.

A rise of around 3°C could be extremely damaging. The IPCC’s earlier assessment said such a rise could mean that more areas would be affected by drought; that up to 30% of species could be at greater risk of extinction; that most corals would face significant biodiversity losses; and that there would be likely increases of intense tropical cyclones and much higher sea levels.

New Model Army

Other recent studies, though, paint a different picture. An unpublished report by the Research Council of Norway, a government-funded body, which was compiled by a team led by Terje Berntsen of the University of Oslo, uses a different method from the IPCC’s. It concludes there is a 90% probability that doubling CO emissions will increase temperatures by only 1.2-2.9°C, with the most likely figure being 1.9°C. The top of the study’s range is well below the IPCC’s upper estimates of likely sensitivity.

This study has not been peer-reviewed; it may be unreliable. But its projections are not unique. Work by Julia Hargreaves of the Research Institute for Global Change in Yokohama, which was published in 2012, suggests a 90% chance of the actual change being in the range of 0.5-4.0°C, with a mean of 2.3°C. This is based on the way the climate behaved about 20,000 years ago, at the peak of the last ice age, a period when carbon-dioxide concentrations leapt. Nic Lewis, an independent climate scientist, got an even lower range in a study accepted for publication: 1.0-3.0°C, with a mean of 1.6°C. His calculations reanalysed work cited by the IPCC and took account of more recent temperature data. In all these calculations, the chances of climate sensitivity above 4.5°C become vanishingly small.

If such estimates were right, they would require revisions to the science of climate change and, possibly, to public policies. If, as conventional wisdom has it, global temperatures could rise by 3°C or more in response to a doubling of emissions, then the correct response would be the one to which most of the world pays lip service: rein in the warming and the greenhouse gases causing it. This is called “mitigation”, in the jargon. Moreover, if there were an outside possibility of something catastrophic, such as a 6°C rise, that could justify drastic interventions. This would be similar to taking out disaster insurance. It may seem an unnecessary expense when you are forking out for the premiums, but when you need it, you really need it. Many economists, including William Nordhaus of Yale University, have made this case.

If, however, temperatures are likely to rise by only 2°C in response to a doubling of carbon emissions (and if the likelihood of a 6°C increase is trivial), the calculation might change. Perhaps the world should seek to adjust to (rather than stop) the greenhouse-gas splurge. There is no point buying earthquake insurance if you do not live in an earthquake zone. In this case more adaptation rather than more mitigation might be the right policy at the margin. But that would be good advice only if these new estimates really were more reliable than the old ones. And different results come from different models.

One type of model—general-circulation models, or GCMs—use a bottom-up approach. These divide the Earth and its atmosphere into a grid which generates an enormous number of calculations in order to imitate the climate system and the multiple influences upon it. The advantage of such complex models is that they are extremely detailed. Their disadvantage is that they do not respond to new temperature readings. They simulate the way the climate works over the long run, without taking account of what current observations are. Their sensitivity is based upon how accurately they describe the processes and feedbacks in the climate system.

The other type—energy-balance models—are simpler. They are top-down, treating the Earth as a single unit or as two hemispheres, and representing the whole climate with a few equations reflecting things such as changes in greenhouse gases, volcanic aerosols and global temperatures. Such models do not try to describe the complexities of the climate. That is a drawback. But they have an advantage, too: unlike the GCMs, they explicitly use temperature data to estimate the sensitivity of the climate system, so they respond to actual climate observations.

The IPCC’s estimates of climate sensitivity are based partly on GCMs. Because these reflect scientists’ understanding of how the climate works, and that understanding has not changed much, the models have not changed either and do not reflect the recent hiatus in rising temperatures. In contrast, the Norwegian study was based on an energy-balance model. So were earlier influential ones by Reto Knutti of the Institute for Atmospheric and Climate Science in Zurich; by Piers Forster of the University of Leeds and Jonathan Gregory of the University of Reading; by Natalia Andronova and Michael Schlesinger, both of the University of Illinois; and by Magne Aldrin of the Norwegian Computing Centre (who is also a co-author of the new Norwegian study). All these found lower climate sensitivities. The paper by Drs Forster and Gregory found a central estimate of 1.6°C for equilibrium sensitivity, with a 95% likelihood of a 1.0-4.1°C range. That by Dr Aldrin and others found a 90% likelihood of a 1.2-3.5°C range.

It might seem obvious that energy-balance models are better: do they not fit what is actually happening? Yes, but that is not the whole story. Myles Allen of Oxford University points out that energy-balance models are better at representing simple and direct climate feedback mechanisms than indirect and dynamic ones. Most greenhouse gases are straightforward: they warm the climate. The direct impact of volcanoes is also straightforward: they cool it by reflecting sunlight back. But volcanoes also change circulation patterns in the atmosphere, which can then warm the climate indirectly, partially offsetting the direct cooling. Simple energy-balance models cannot capture this indirect feedback. So they may exaggerate volcanic cooling.

This means that if, for some reason, there were factors that temporarily muffled the impact of greenhouse-gas emissions on global temperatures, the simple energy-balance models might not pick them up. They will be too responsive to passing slowdowns. In short, the different sorts of climate model measure somewhat different things.

Clouds of uncertainty

This also means the case for saying the climate is less sensitive to CO emissions than previously believed cannot rest on models alone. There must be other explanations—and, as it happens, there are: individual climatic influences and feedback loops that amplify (and sometimes moderate) climate change.

Begin with aerosols, such as those from sulphates. These stop the atmosphere from warming by reflecting sunlight. Some heat it, too. But on balance aerosols offset the warming impact of carbon dioxide and other greenhouse gases. Most climate models reckon that aerosols cool the atmosphere by about 0.3-0.5°C. If that underestimated aerosols’ effects, perhaps it might explain the lack of recent warming.

Yet it does not. In fact, it may actually be an overestimate. Over the past few years, measurements of aerosols have improved enormously. Detailed data from satellites and balloons suggest their cooling effect is lower (and their warming greater, where that occurs). The leaked assessment from the IPCC (which is still subject to review and revision) suggested that aerosols’ estimated radiative “forcing”—their warming or cooling effect—had changed from minus 1.2 watts per square metre of the Earth’s surface in the 2007 assessment to minus 0.7W/m ² now: ie, less cooling.

One of the commonest and most important aerosols is soot (also known as black carbon). This warms the atmosphere because it absorbs sunlight, as black things do. The most detailed study of soot was published in January and also found more net warming than had previously been thought. It reckoned black carbon had a direct warming effect of around 1.1W/m ². Though indirect effects offset some of this, the effect is still greater than an earlier estimate by the United Nations Environment Programme of 0.3-0.6W/m ².

All this makes the recent period of flat temperatures even more puzzling. If aerosols are not cooling the Earth as much as was thought, then global warming ought to be gathering pace. But it is not. Something must be reining it back. One candidate is lower climate sensitivity.

A related possibility is that general-circulation climate models may be overestimating the impact of clouds (which are themselves influenced by aerosols). In all such models, clouds amplify global warming, sometimes by a lot. But as the leaked IPCC assessment says, “the cloud feedback remains the most uncertain radiative feedback in climate models.” It is even possible that some clouds may dampen, not amplify global warming—which may also help explain the hiatus in rising temperatures. If clouds have less of an effect, climate sensitivity would be lower.

So the explanation may lie in the air—but then again it may not. Perhaps it lies in the oceans. But here, too, facts get in the way. Over the past decade the long-term rise in surface seawater temperatures seems to have stalled (see chart 2), which suggests that the oceans are not absorbing as much heat from the atmosphere.

As with aerosols, this conclusion is based on better data from new measuring devices. But it applies only to the upper 700 metres of the sea. What is going on below that—particularly at depths of 2km or more—is obscure. A study in Geophysical Research Letters by Kevin Trenberth of America’s National Centre for Atmospheric Research and others found that 30% of the ocean warming in the past decade has occurred in the deep ocean (below 700 metres). The study says a substantial amount of global warming is going into the oceans, and the deep oceans are heating up in an unprecedented way. If so, that would also help explain the temperature hiatus.

Double-A minus

Lastly, there is some evidence that the natural (ie, non-man-made) variability of temperatures may be somewhat greater than the IPCC has thought. A recent paper by Ka-Kit Tung and Jiansong Zhou in the Proceedings of the National Academy of Sciences links temperature changes from 1750 to natural changes (such as sea temperatures in the Atlantic Ocean) and suggests that “the anthropogenic global-warming trends might have been overestimated by a factor of two in the second half of the 20th century.” It is possible, therefore, that both the rise in temperatures in the 1990s and the flattening in the 2000s have been caused in part by natural variability.

So what does all this amount to? The scientists are cautious about interpreting their findings. As Dr Knutti puts it, “the bottom line is that there are several lines of evidence, where the observed trends are pushing down, whereas the models are pushing up, so my personal view is that the overall assessment hasn’t changed much.”

But given the hiatus in warming and all the new evidence, a small reduction in estimates of climate sensitivity would seem to be justified: a downwards nudge on various best estimates from 3°C to 2.5°C, perhaps; a lower ceiling (around 4.5°C), certainly. If climate scientists were credit-rating agencies, climate sensitivity would be on negative watch. But it would not yet be downgraded.

Equilibrium climate sensitivity is a benchmark in climate science. But it is a very specific measure. It attempts to describe what would happen to the climate once all the feedback mechanisms have worked through; equilibrium in this sense takes centuries—too long for most policymakers. As Gerard Roe of the University of Washington argues, even if climate sensitivity were as high as the IPCC suggests, its effects would be minuscule under any plausible discount rate because it operates over such long periods. So it is one thing to ask how climate sensitivity might be changing; a different question is to ask what the policy consequences might be.

For that, a more useful measure is the transient climate response (TCR), the temperature you reach after doubling CO gradually over 70 years. Unlike the equilibrium response, the transient one can be observed directly; there is much less controversy about it. Most estimates put the TCR at about 1.5°C, with a range of 1-2°C. Isaac Held of America’s National Oceanic and Atmospheric Administration recently calculated his “personal best estimate” for the TCR: 1.4°C, reflecting the new estimates for aerosols and natural variability.

That sounds reassuring: the TCR is below estimates for equilibrium climate sensitivity. But the TCR captures only some of the warming that those 70 years of emissions would eventually generate because carbon dioxide stays in the atmosphere for much longer.

As a rule of thumb, global temperatures rise by about 1.5°C for each trillion tonnes of carbon put into the atmosphere. The world has pumped out half a trillion tonnes of carbon since 1750, and temperatures have risen by 0.8°C. At current rates, the next half-trillion tonnes will be emitted by 2045; the one after that before 2080.

Since CO accumulates in the atmosphere, this could increase temperatures compared with pre-industrial levels by around 2°C even with a lower sensitivity and perhaps nearer to 4°C at the top end of the estimates. Despite all the work on sensitivity, no one really knows how the climate would react if temperatures rose by as much as 4°C. Hardly reassuring.

Waste not, want not

Waste not, want not

Follow @ ShereeHanna

Governments need to push harder if renewable energy schemes are going to be wholeheartedly utilised to eradicate the global problem of landfill.

Richard Wardrop, Operations Director of Durban-based technical and management company, Environmental Waste Solutions, believes the political will to deal with landfill issues is not present.

However, his company is doing its utmost to change the status quo, using a process which harnesses plasma arc gasification technology for the eradication of landfill, which in turn produces energy.

He said: “My own opinion is that the political will to deal with landfill is not really there. I think there has to be something in legislation whereby Government says to municipalities and councils ‘that’s it, you are not going to be able to use landfill after a certain day. There won’t be any landfill tax because there will be no landfill’.

“I get very frustrated by the lack of action by politicians supported by civil servants who see anything which impacts on their workload as a nuisance and my experiences in both Africa and the UK are exactly the same.”

Light on horizon

However, Wardrop believes that the future of renewable energy schemes is as bright in South and Southern Africa as it is in Europe and the US and with good reason.

EWS, which has its holding company in the UK, is currently in negotiations for its first gasification plant in the Kwa-Zulu Natal province which would be capable of generating 50 MegaWatts of power from the waste it can process.

The EWS solution means that that a lesser amount of the electricity will be lost because it is generated at the point of use and doesn’t have to be sent down a transmission line, unlike conventional methods which result in power transmission losses.

The technology which EWS uses has been developed by Israeli company Environmental Energy Resources Ltd. However, it was originally the work of leading scientists at the Kurchatov Institute in Russia, a world renowned scientific institution for treatment of low-level radioactive waste.

Wardrop said: “You basically get two huge bonuses from one project, eliminating landfill and generating power. However, many people get confused by the process of gasification and incineration.

“With gasification, the temperatures used in the process are much higher which destroy all the toxins present and at the end leave a resin-type substance which is totally inert and can be used for road-fill or foundations for houses, etc.”

Pure power

It is a very clean process which produces a gas that can be used in engines, turbines or combined heat cycle machines and it generates 1.25 megawatts of power for every 10,000 tons of waste. Plus, the amount of thermal energy produced by the process equates to 2.75 MW of thermal energy per 10,000 tonnes of MSW processed.

The plant, which is hoped will be commissioned early in 2015, will create 200 jobs during its construction and then 70 in the long term.

EWS is working with a private in Black Economic Empowerment (BEE) group, who has won the contract to own, operate and run the plant.

“About 60 percent of what is required for the plant will be manufactured locally. We will act as the technical suppliers and advisors while the BEE group own, manage and operate the day-to-day operations,” said Wardrop.

“I am confident that once the plant is installed, up and running there will be a queue of people coming to us wanting to do the same thing. We will certainly be looking to do similar projects in the Southern Africa Development Community (SADC) region.”

Wardrop pointed out that looking at the current statistics for South Africa 3 GW of power could be generated from the country’s collected waste, which equates to the same amount of power from a conventional power station.

He said: “the issue is that landfill in its own right is an iniquitous thing to do. The legacy we are leaving for future generations is the legacy we are leaving now because if you travel around the world to any city or town there will be a hole in the ground somewhere full of rotting rubbish and really who would want to live on a landfill site. It is primitive.”
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New microbe makes fuel from CO2 in the air | MNN – Mother Nature Network

New microbe makes fuel from CO2 in the air

Scientists at the University of Georgia have created a microbe that converts carbon dioxide into biofuel, a discovery that might boost the battle against climate change.

Wed, Mar 27 2013 at 1:36 PM

Related Topics:

Biofuels, CO2, Global Warming, Greenhouse Gases, Science

CO2 emissions billow up from a smokestack. (Photo: U.S. Environmental Protection Agency)

Carbon dioxide is a major cause of global warming, but it’s also fundamental to life on Earth. As any good toxicologist knows, “the dose makes the poison.”

And thanks to new research at the University of Georgia, we might soon have an antidote for too much CO2: a manmade version of the microbe Pyrococcus furiosus, or “rushing fireball,” that absorbs CO2 and converts it into fuel. If P. furiosus can work on a large enough scale, it might even help displace carbon-positive fossil fuels like coal and oil.

“Basically, what we have done is create a microorganism that does with carbon dioxide exactly what plants do — absorb it and generate something useful,” says Michael Adams, a member of UGA’s Bioenergy Systems Research Institute and co-author of a new study detailing the magic of P. furiosus. “What this discovery means is that we can remove plants as the middleman. We can take carbon dioxide directly from the atmosphere and turn it into useful products like fuels and chemicals without having to go through the inefficient process of growing plants and extracting sugars from biomass.”

In photosynthesis, plants use sunlight to turn water and CO2 into energy-packed sugars, forming the base of Earth’s food web. These sugars can also be fermented into biofuels like ethanol, but as Adams points out, removing them from a plant’s cells is relatively inefficient due to the energy input required. P. furiosus, however, may offer a shortcut.

The microbe is a deep-sea “extremophile,” thriving in violent conditions that would obliterate most organisms. It feeds on carbohydrates in super-heated seawater around hydrothermal vents, but by tweaking its genetic material, Adams and his colleagues created a new kind of P. furiosus that likes cooler temperatures and eats CO2.

The researchers then used hydrogen gas to spark a chemical reaction inside the microbe, prompting it to incorporate CO2 into 3-hydroxypropionic acid, a common industrial acid that’s used to make acrylics. With further genetic manipulations, they can also create a P. furiosus variant that produces an array of other useful chemicals, including fuel. And when that biofuel is burned, the researchers note, it releases the same amount of CO2 that was used to create it. That means it’s essentially carbon-neutral, making it a cleaner alternative to fossil-based fuels like coal, crude oil and gasoline.

“This is an important first step that has great promise as an efficient and cost-effective method of producing fuels,” Adams says. “In the future we will refine the process and begin testing it on larger scales.”

New Air Plan

Download PDF : New_Air_Plan_en

Air pollution plan not a rehash, says government


Friday, 29 March, 2013, 12:00am

News›Hong Kong


Cheung Chi-fai

Government denies its manifesto for cleaning up air quality contains nothing new and trades on ideas of the former administration

The government has rejected claims that its seven-year clean-air plan, released yesterday, is nothing but a rehash of the previous administration’s ideas.

Critics have said the road map – billed as the most comprehensive plan yet to improve Hong Kong’s air quality – features very few new ideas or measures.


Undersecretary for the environment Christine Loh Kung-wai defended the strategy.

“[The plan] shows the strong intensity and determination of the government and what our priorities are,” Loh said.

One new measure, outlined by Secretary for Transport and Housing Professor Anthony Cheung Bing-leung, aims to plug a loophole in prosecuting operators of smoky vessels. Cheung said plans for a law to introduce the Ringelmann chart would be presented to the legislature later this year.

The chart tracks the colour of smoke from white through shades of grey to black. Any vessel with smoke darker than a particular shade for more than three minutes would be liable to prosecution. Current law makes emitting dark smoke an offence only if it is proved to be a nuisance.

But aside from this initiative, critics say most of the measures have been announced by the previous administration.

Angus Wong, policy advocacy manager of World Green Organisation, was disappointed with the plan.

“It is old wine, new bottles, to some extent. But I don’t think they could come up with something drastically new,” he said.

He called on officials to implement all those previous measures and then consider addressing planning shortcomings that have trapped air pollutants in the city.

Professor Wong Tze-wai, an air pollution expert at Chinese University, said officials should be given time to do their work.

“We should not pour cold water on them right now,” he said.

Measures outlined in the road map include cleaner fuel for ships, retrofitting buses with emission controls, and better research into air pollution.

The government has promised to introduce legislation to require cleaner fuel for local vessels this year and ocean-going ships in port next year.

Loh said it had also initiated talks with Guangdong on a similar requirement for berthed ships at the province’s ports.

By the turn of the decade, she said, the Pearl River Delta region, including Hong Kong and Macau, could be turned into an emission-control area requiring even cleaner fuel.

About 1,400 old franchised buses will be retrofitted with selective catalytic reduction devices by 2016, in an attempt to lower nitrogen dioxide emissions.

Talks are still continuing with commercial diesel truck operators on phasing out old vehicles under a HK$10 billion scheme

On building up air science, Loh said local universities were exploring research to gauge the health impacts of air pollution.

She said environment officials would also be sent to Geneva to learn from air experts of the World Health Organisation.

Permanent secretary for development Wai Chi-sing said the bureau would build a city-wide cycling network and incorporate air-flow assessment in government works projects in the future.

Undersecretary for food and health Professor Sophia Chan Siu-chee said health officials would provide professional advice on the impact of air pollution by tracking international trends and standards.


Air Pollution

Christine Loh Kung-Wai

Anthony Cheung Bing-Leung

Source URL (retrieved on Mar 29th 2013, 9:12am):


Plan to give Hong Kong world-class air quality in 7 years


Plan to give Hong Kong world-class air quality in 7 years

Friday, 29 March, 2013, 12:00am

News›Hong Kong


Cheung Chi-fai

But they caution some pollutants will persist even after new standards are introduced

Top officials yesterday unveiled a seven-year plan to cut Hong Kong’s notorious roadside air pollution, while admitting some of the targets might be hard to meet.

Billed as an air-quality roadmap to 2020, the plan says that if all measures are fully introduced, roadside pollution will begin to drop in the next two to three years, and see significant improvement in four to five.

But the officials admitted that the level of nitrogen dioxide, the dominant pollutant, will remain almost double the new standards to be introduced next year despite a 40 per cent drop.

“Our goal is for Hong Kong to be among the best in the world in understanding air quality so that we can continue to fight air pollution aggressively,” Environment Secretary Wong Kam-sing said.

Our goal is for Hong Kong to be among the best in the world in understanding air quality so that we can continue to fight air pollution aggressively

Environment Secretary Wong Kam-sing

He was joined at a press conference by Transport Minister Anthony Cheung Bing-leung and senior officials from the bureaus for development and food and health in a move Wong said showed co-operation and commitment across government.

Cheung, who oversees public and private transport operators – a key target of many measures – said his bureau aimed to improve air quality but it needed to be balanced with operators’ needs.

The measures include phasing out old diesel commercial trucks, retrofitting buses with emission controls and cleaner fuel for ships.

The plan projects that by 2020, the concentration of carcinogenic respirable suspended particles at the roadside will drop by 25 per cent from 60 micrograms per cubic metre of air in 2011 to 45 micrograms – below the new tightened standard.

Officials warned that nitrogen dioxide levels would still exceed the new standard despite falling 40 per cent to 75 micrograms.

Undersecretary for the Environment Christine Loh Kung-wai said the unique character of the city, with its high population and building density, made it difficult to tackle a nitrogen dioxide problem that also plagued London.

Loh said rectifying it might require tougher measures. “We might have to expand the pedestrianised areas or divert some traffic. But we are still exploring these and that’s why they are not in the plan now,” she said.

The joint approach raises hopes that the lack of policy bureau co-ordination in fighting air pollution – highlighted in the last report of the Audit Commission – will become a thing of the past.

But Friends of the Earth was not convinced as the plan lacked a mechanism for co-operation, while it was unclear what responsibility each bureau would shoulder for not meeting targets.

The group, along with Green Sense, protested outside the government headquarters over what they see as officials’ over-emphasis on infrastructure development at the expense of air quality.

Wong said the air targets might still be achieved even with development, while Loh said the whole government would take the blame or credit for missing or meeting the air targets.

Pending legislature approval, a new set of air-quality objectives will be introduced next year to replace those in use since 1987.

A health-based air pollution alert system modelled on that used in Canada will be introduced at the same time.

Measures proposed to fight air pollution in Hong Kong

  • Retrofit 1,400 franchised buses with selective catalytic reduction devices by 2016 to control harmful diesel-engine emissions
  • Mandate a fuel switch for ocean-going vessels berthing at Hong Kong and explore the feasibility of extending the switch to Pearl River Delta ports
  • Update air-quality objectives next year and introduce a new health-based air-pollution alert system
  • Collaborate with Guangdong to cut emissions from factories in the delta region
  • Strengthened emission controls for petrol and LPG vehicles
  • Low-emission zones for franchised buses


Air Pollution

Roadside pollution

Wong Kam-sing

Christine Loh Kung-Wai

More on this:

Most cities hiding vital pollution data from public [1]

Air pollution plan not a rehash, says government [2]

Source URL (retrieved on Mar 29th 2013, 8:59am):


WHO will help set Hong Kong’s air quality goals


Thursday, 28 March, 2013, 12:00am

News›Hong Kong


Cheung Chi-fai

Government is believed to be calling in global experts as it sets out a seven-year road map

World Health Organisation experts will help set Hong Kong’s air quality objectives, according to a schedule to be released by the Environment Bureau today, a source close to the government says.

The 40-page road map for Clean Air for Hong Kong will outline the targets and timetables for improving air quality.

The document, to be launched by Secretary for the Environment Wong Kam-sing, will cover at least the next seven years and is expected to be the most comprehensive air quality blueprint for Hong Kong yet.

The plan will include government measures to curb emissions at local sources, from roads to marine transport and power generation. It will also highlight the need for co-operation with Guangdong in addressing regional smog caused by ground-level ozone pollution.

The source said it would also focus on the link between public health and air pollution, and the need for long-term local health studies, as well as possible funding sources for this research.

But room for new local measures seemed limited, as the bureau had recently already rolled out or announced a number of measures. These included phasing out old, polluting trucks by 2019, with the help of HK$10 billion earmarked by Chief Executive Leung Chun-ying.

It is understood that the bureau has been shortlisting experts to review its objectives and advise on studies through the WHO’s director general Margaret Chan Fung Fu-chun.

“It is hoped the experts can help determine how far Hong Kong can go in setting the air quality targets,” the source said. “[The road map] will also give ammunition to environment officials [trying to] improve air quality in future.”

It is hoped the experts can help determine how far Hong Kong can go in setting the air quality targets

To highlight co-operation between different bureaus and departments, Wong will be joined in the announcement by Secretary for Transport and Housing Professor Anthony Cheung Bing-leung, undersecretary for food and health Professor Sophia Chan Siu-chee, and permanent secretary for development Wai Chi-sing.

“The Environment Bureau wanted to get Dr Ko Wing-man, the secretary for health and food, involved to highlight the importance of the issue. It is far more convincing for Ko to tell the public what is bad for their health than Wong,” the source said.

But a spokesman for Ko said the health minister had to show up at another event that would clash with the press conference.

“Dr Ko will attend a doctors’ event about Sars at Nethersole Hospital. He had promised to attend the event before the [press] conference was finalised,” the spokesman said.

Early last year, environment officials announced new air quality targets to be introduced next year, but the Audit Commission said the targets were not sufficient to protect public health.

The officials also listed at least 19 measures to reach the targets, some of which are already in use.


World Health Organisation

Clean Air for Hong Kong

Air quality

Source URL (retrieved on Mar 28th 2013, 8:25am):

Air pollutant emissions from aircraft

Hong Kong (HKSAR) – Following is a question by the Hon Chan Hak-kan and a
written reply by the Secretary for the Environment, Mr Wong Kam-sing, in
the Legislative Council today (March 27):

According to the 2010 Hong Kong Air Pollutants Emission Inventory
published by the Environmental Protection Department, emissions of three
types of air pollutants, namely sulphur dioxide, nitrogen oxides and
carbon monoxide, from civil aviation in 2010 were higher than those in
2008. The Environmental Report 2010 published by the Civil Aviation
Department pointed out that, since the adjustment of the airways for
arrival aircraft from the west and the north of Hong Kong in October 2009
to shorten the travelling distances, carbon dioxide emissions from civil
aviation in 2010 were estimated to have dropped by about 350 000 tonnes.
In this connection, will the Government inform this Council:

(a) of the emissions of various air pollutants from aircraft in 2011 and
2012; any specific measures to reduce air pollutant emissions from
aircraft movements and aircraft parking at the Hong Kong International
Airport (HKIA);

(b) of the number of airways in the Hong Kong Flight Information Region
at present; whether the authorities have assessed the air pollutant
emissions from aircraft using various airways, and the impact of such air
pollutant emissions on Hong Kong¡¦s air quality; if they have, the
assessment result;

(c) of the districts where the air pollutant emissions from aircraft have
currently greater impact on the ground-level air quality; whether it has
assessed the risks posed by air pollutant emissions from aircraft on the
public health; if it has, of the assessment outcome;

(d) whether it knows which models of aircraft or what regions from which
they come have caused more serious air pollution, and the corresponding
measures taken by the authorities;

(e) whether it has assessed if the visibility in the vicinity of HKIA had
been affected by air pollution caused by aircraft movements and parking
in the past three years; if visibility had been affected, of the details,
and the corresponding measures taken by the authorities to ensure
aviation safety; and

(f) given a number of airports in the Pearl River Delta Region at
present, whether the authorities of Guangdong Province, Hong Kong and
Macao have jointly established a mechanism, so as to reduce air pollution
caused by aircraft movements and parking in these airports?



(a) Every year, the Environmental Protection Department (EPD) publishes
an annual emission inventory for Hong Kong listing out the quantities of
emissions of major emission sources.

On March 20, 2013, we published the emission inventory for 2011. The
emission inventory for 2012 is under preparation. According to the
published emission inventory, the total quantities of air pollutants
emitted during the arrivals, departures and parking of aircraft at the
HKIA in 2011 are set out in table 1.

Annex 16 to the Convention on International Civil Aviation, Volume 2,
Part III, Chapter 2 specifies emission standards of air pollutants for
commercial aircraft including smoke, unburned hydrocarbons, carbon
monoxide and nitrogen oxides. All commercial aircraft operating in Hong
Kong have to comply with these emission standards to reduce their

Since 2009, the Civil Aviation Department (CAD) has implemented new
airways that shortened the travelling distances for arrival aircraft from
the west and the north of Hong Kong to reduce the emissions of air
pollutants and carbon dioxide from aircraft. During 2011, more than
63,000 flights benefited from the shortened arrival routes and it is
estimated that up to 390,000 tonnes of carbon dioxide were reduced.

Since its operation, the Airport Authority (AA) has provided electricity
powered fixed ground power (FGP) and pre-conditioned air (PCA) systems
for aircraft at parking stands to minimise the need for aircraft to use
their on-board fuel combustion auxiliary power generation units so as to
reduce their emissions.

About 80% of aircraft have now adopted the FGP and PCA systems. In 2014,
the AA will mandate aircraft at parking stands to use FGP and PCA

(b) and (c) There are currently five main airways in Hong Kong to
accommodate aircraft arriving and departing at the HKIA.

In 2011, the AA commissioned the Hong Kong University of Science and
Technology to analyse the correlation between the emissions from the HKIA
and other areas in the North Lantau based on air quality data recorded at
the air quality monitoring stations in the vicinity of the airport from
March 2006 to February 2010.

The analytical results revealed that exceedances of the Air Quality
Objectives at Tung Chung were mainly due to ozone and respirable
suspended particulates primarily caused by regional air pollution instead
of emissions from the airport. Hence, the impact of emissions from the
airport on the air quality of Tung Chung is not significant.

Aircraft are flying at high altitudes most of the time except during
landing, take-off and taxiing that are close to the ground. Therefore,
emissions from aircraft have little impact on the air quality in other
districts in the region.

(d) All aircraft operating in Hong Kong have to comply with the emission
standards set out in the Convention on International Civil Aviation.

The total quantities of air pollutants emitted from individual models of
aircraft depend on a number of factors including the numbers of their
arrivals and departures in a year, the type, size and number of
engines.Even for aircraft of the same model, they may not have engines of
the same types or sizes and could have different quantities of
emissions.In general, larger aircraft with higher arrival and departure
frequencies will have greater quantities of emissions.

(e) The annual aircraft arrivals and departures at the HKIA increased by
16.8 per cent in the last five years. According to the record of the Hong
Kong Observatory in the same period, the number of hours of reduced
visibility recorded at the HKIA dropped from 1,951 hours in 2008 to 826
hours in 2012, down by 58 per cent. The annual averaged concentration of
fine suspended particulates (PM2.5), which is closely correlated to
visibility, recorded at EPD’s Tung Chung general air quality monitoring
station also showed a reduction of 24 per cent in the same period, from
37 ug/m3 in 2008 to 28 ug/m3 in 2012.

These data show that the visibility in the vicinity of airport was not
significantly affected by movements and parking of aircraft. Detailed
data are tabulated in table 2.

CAD, together with the AA and aircraft operators, have put in place
established procedures for air traffic control and ground operations at
the HKIA under reduced visibility conditions to ensure flight safety and
smooth operation. Such procedures include increasing nominal spacing
between aircraft, enhancing the safeguards of navigation signals, special
airfield ground light settings, closure of certain vehicular routes, etc.

(f) As mentioned in the reply to (b) and (c) above, emissions from
aircraft have little impact on air quality in the region.

Emission standards set out in Annex 16 to the Convention on International
Civil Aviation applies to aircraft arriving at the Guangdong Province,
Hong Kong and Macao for reducing emissions from aircraft movements.

Source: HKSAR Government

Technique produces hydrogen from landfill incinerator ash

Swedish researchers have created a way of turning ash from power stations run on landfill waste into hydrogen.

The heavy, grit-like bottom ash formed by burning rubbish is often used to cover landfills or as a construction material but gradually releases hydrogen when stored so is usually kept in the open so the gas can escape in order to avoid an explosion risk.

The scientists from Lund University have a developed a technique of dampening the bottom ash with water in an oxygen-free environment to rapidly release the hydrogen, which can then be collected and stored.

‘The ash can be used as a resource through recovery of hydrogen gas instead of being allowed to be released into the air as at present,’ said Aamir Ilyas, doctor of water resources engineering at Lund University and the developer of the technique.

‘A bonus is that this method removes the risk of hydrogen gas. It also reduces the strain on our landfill sites.’

The researchers estimate that use of this technique has the potential to generate 20 billion litres of hydrogen gas a year – 56 gigawatt-hours (GWh) worth of energy.

Hydrogen is most commonly produced from natural gas or other fossil fuels but a small proportion is now manufactured from gassifying biomass or electrolysing water.

Kenneth Persson, professor of water resources engineering and one of Ilyas’s supervisors at Lund suggested this method could contribute to the more environmentally friendly generation of hydrogen.

‘There will not be one universal solution that will be used to generate energy. We need to find a number of solutions,’ he said.

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TAC discusses bus route rationalisation and phasing out heavily polluting diesel commercial vehicles

The Transport Advisory Committee (TAC) was briefed today (March 26) on the Administration’s more comprehensive and vigorous approach in rationalising bus routes to better meet passenger demand, enhance bus operation efficiency, reduce pressure on fare increase, alleviate traffic congestion, and reduce roadside emissions, noting that this is a policy initiative announced in the Policy Address in January 2013.

“In view of the need for and benefits of rationalising bus services from both transport and environmental perspectives, the TAC supports the Government and franchised bus companies to pursue route rationalisation measures with greater vigour and determination. Members welcome the new “area approach” as well as the enhancement in interchange arrangements in rationalising bus services,” the TAC Chairman, Mr Larry Kwok said.

TAC Members were also briefed on the Government’s proposal to phase out heavily polluting diesel commercial vehicles by an incentive-cum-regulatory approach and to limit the service life of newly registered diesel commercial vehicles at 15 years as announced in the 2013 Policy Address, in order to improve roadside air quality and protect public health.

Members noted that there are about 86 000 pre-Euro IV diesel commercial vehicles in Hong Kong accounting for 66 per cent of the diesel commercial vehicle fleet. These vehicles together emit about 90 per cent of respirable suspended particulates and 63 per cent of nitrogen oxides from all diesel commercial vehicles.

“Members welcome the Government’s plan to phase out heavily polluting diesel commercial vehicles by an incentive-cum-regulatory approach,” Mr Kwok said.

Ends/Tuesday, March 26, 2013
Issued at HKT 18:24