Mercury pollution from decades past may have been re-released by Tasmania’s bushfires



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Tasmania’s fires may have released mercury previously absorbed by trees.
AAP Image

Larissa Schneider, Australian National University; Kathryn Allen, University of Melbourne, and Simon Haberle, Australian National University

Tasmania’s bushfires may have resulted in the release of significant amounts of mercury from burnt trees into the atmosphere. Our research shows that industrial mercury pollution from decades past has been locked up in west Tasmanian trees.

Mercury occurs naturally in Earth’s crust. Over the past 200 years, industrial activities have mobilised mercury from the crust and released it into the atmosphere. As a consequence, atmospheric mercury concentrations are now three to four times higher than in the pre-industrialisation era.

Mining is the largest source of the global atmospheric mercury, accounting for 37% of mercury emissions. When Europeans first arrived in Australia, there was, of course, no Environmental Protection Act in place to limit emissions from industrial activities. In western Tasmania, where mining has occurred for more than a century, this meant mercury was being released without control into the local atmosphere until changes in technology, market conditions, and later, regulation, conspired to reduce emissions.




Read more:
Australia emits mercury at double the global average


Because mercury is also very persistent in the environment, past mining activity has generated a reservoir of mercury that could be released to the atmosphere under certain conditions. This is a concern because even small amounts of mercury may be toxic and may cause serious health problems. In particular, mercury can threaten the normal development of a child in utero and early in its life.

Tree rings can reveal past mercury contamination

How much mercury has been released into the Australian environment and when has remained largely unknown. However, in a new study we show how mercury levels in Tasmania have dramatically changed over the past 150 years due to mining practices. Long-lived Huon pine, endemic to western Tasmania, is one of the most efficient bioaccumulators of mercury in the world. This makes it a good proxy for tracking mercury emissions in western Tasmania. If concentrations of mercury in the atmosphere are high in a given year, this can be detected in the annual ring of Huon pine for that year.

Mercury pollution from past mining practices in western Tasmania has left a lasting environmental legacy. The sampled trees contained a significant reservoir of mercury that was taken up during the peak mining period in Queenstown. Changes in mercury concentrations in the annual rings of Huon pine are closely aligned with changes in mining practices in the region.

Increased concentrations coincide with the commencement of pyritic copper smelting in Queenstown in 1896. They peak between 1910 and 1920 when smelting was at its height. In 1922, concentrations begin to decline in parallel with the introduction of a new method to separate and concentrate ores. This method required only one small furnace instead of 11 large ones. In 1934, a new dust-collection apparatus was installed in the smelter’s chimney, coinciding with the further decrease in mercury concentrations in nearby Huon pine.

Temporal tree rings of Huon pine, revealing historical mercury pollution.
Author provided

Toxic elements or compounds taken up by vegetation can also be released back into the local environment. Bushfires that burn trees that have accumulated mercury may release this mercury as vapour, dust or fine ash, potentially exposing people and wildlife to the adverse effects of mercury. It is estimated that bushfires release 210,000kg of mercury into the global atmosphere each year. As these fires become more frequent and ferocious in Australia, mercury concentrations in the atmosphere are likely to increase. Mercury released by bushfires can persist in the atmosphere for a year, allowing for long-distance transportation depending on wind strength and direction. This means that mining activity from over a century ago may have regional implications in the near future. The Tasmanian fires in December-February burned almost 200,000 hectares, including areas around Queenstown.

It is not currently possible to know how much mercury has been released by these recent fires. Our results simply highlight the potential risk and the need to better understand the amount of mercury taken up by vegetation that may one day be released back to the atmosphere via bushfires.

Re-release of historical mercury emissions by bushfires.
Author provided



Read more:
Dry lightning has set Tasmania ablaze, and climate change makes it more likely to happen again


Although there is no simple way to remove bio-accumulated mercury from trees, the history of mercury contamination recorded in tree rings provides important lessons. Decreased uptake of mercury after upgrades to the Queenstown copper smelter operations demonstrates the positive impact that good management decisions can have on the amount of mercury released into the environment.

To control mercury emissions globally, the United Nations Environment Programme (UNEP) has developed the Minamata Convention on Mercury. Its primary goal is to protect human health and the environment from the negative effects of mercury. Australia has signed the convention and but has yet to ratify it. Once ratified, Australia would be required to record sources of mercury and quantify emissions, including those from bushfires.

But to do this, the government must first be able to identify environmental reservoirs of mercury. Our study, the first of its kind in the Southern Hemisphere, shows that the long-lived Huon pine can be used to for this purpose. Further work to determine what other tree species record atmospheric emissions of mercury and other toxic elements in other regions of Australia is required.The Conversation

Larissa Schneider, DECRA fellow, Australian National University; Kathryn Allen, Academic, Ecosystem and Forest Sciences, University of Melbourne, and Simon Haberle, Professor, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Logging burns conceal industrial pollution in the name of ‘community safety’



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High intensity logging burns and the resulting smoke plume near Mount Baw Baw, April 2018
Photo Chris Taylor., Author provided

Chris Taylor, University of Melbourne and David Lindenmayer, Australian National University

Earlier this year, Melbourne and large areas of Central Victoria, experienced days of smoke haze and poor air quality warnings as a result of planned burns. It’s a regular event occurring every autumn.

This smoke has been reported by both government and media outlets as largely the result of planned burns to reduce bushfire risk, along with agricultural burn-offs and increased use of wood heaters.




Read more:
Firestorms: the bushfire/thunderstorm hybrids we urgently need to understand


But this is only part of the story. A good proportion of the smoke this autumn has actually come from the intensive burning of debris left behind after clearfell logging. This is essentially industrial pollution.

Smoke Haze over Mooroolbark and Melbourne’s eastern suburbs on Tuesday 1 May 2018, shortly after the time when the Poor Air Quality Index reached 901.
Photo: Chris Taylor, Author provided

Industrial clearfell logging vs fuel reduction

To understand why clearfell logging burns are different compared with planned burns to reduce bushfire risk, we need to understand clearfell logging, which involves cutting most or all of the commercially valued trees in one single operation across a designated area (called a “coupe”).

Large volumes of forest biomass are left on the ground following clearfell logging in the Mount Disappointment State Forest with the Melbourne City Skyline in the background, August 2010.
Photo. Chris Taylor., Author provided

In the process of clearfell logging, understorey vegetation is usually pushed over. Along with tree heads and branches left behind after logging, large volumes of debris – known as “slash” – are created. This is partially removed by applying a high intensity burn across the coupe, which in turn establishes an ash seed bed for the next crop of trees to be established. Generally, around 90-100% of the coupe is burnt.

In contrast, planned burns to reduce bushfire risk (otherwise referred to as fuel reduction burns) are less intense. They mostly target “fine fuels” (vegetation less than 6mm in diameter) on the forest floor and in the understorey, which may average around 15 tonnes per hectare (t/ha). Burn coverage is usually 50-70% of the site.

Surface and understorey ‘fine fuels’ targeted in a recent low intensity burn near Mt Dandenong in April 2018.
Photo: Chris Taylor, Author provided

Clearfell logging burns consume much larger volumes of vegetation biomass in the form of tree heads, branches, bark and downed understorey vegetation. According to a report completed for the National Carbon Accounting System, clearfell logging burns consume, on average, 130 t/ha of slash in mixed-species forest and 140 t/ha of slash in Mountain Ash forests. This means that, while clearfell logging burns cover much less ground than fuel reduction burns, they burn far more biomass per hectare – generating far more smoke.

The list of planned burns on Forest Fire Management Victoria’s website showed that, at the beginning of May, 77 of the 119 burns either lit or planned to be lit across the Central Highlands of Victoria and surrounding areas were on logging coupes.




Read more:
After the firestorm: the health implications of returning to a bushfire zone


These burns were individually lit over a period of weeks, with some days predominantly logging burns, others fuel reduction burns. An example when logging burns were prominent occurred on April 20 this year, where 10 out of 12 planned burns were observed as occurring on logging coupes. Using a simple calculation based on average biomass consumption, fuel loads and burn coverage for logging and fuel reduction burns, we estimate that up to 99% of biomass burnt most likely occurred on logging coupes. The following day, the Environmental Protection Authority observed “poor” air quality at multiple air monitoring stations across Melbourne due to smoke.

MODIS Rapid Response Terra Satellite image taken 20 April 2018 showing the smoke intensity of the logging burns.
NASA 2018

Even on days when the majority of burns lit were for fuel reduction, planned logging burns still contributed a proportion of biomass burned. For example, on April 30, only three out of 12 planned burns were observed as occurring on logging coupes, but they may have contributed to around one-third of the total biomass burned.




Read more:
Future bushfires will be worse: we need to adapt now


Likewise, on the following day, the Environmental Protection Authority observed “very poor” air quality across multiple air monitoring stations. While multiple planned burns contributed to this pollution event, we contend that logging burns increased the levels of pollution in addition to the smoke originating from fuel reduction burns.

MODIS Rapid Response Terra Satellite image taken 30 April 2018 showing the smoke intensity of the planned burns.
NASA 2018

The key issue here is that not all “planned burns” are equivalent. Fuel reduction burns are intended to reduce the bushfire risk to lives and property. Indeed, work led by The Australian National University shows that regular fuel reduction burns can reduce risk to properties if carried out within close proximity.

In contrast, clearfell logging burns are part of an industrial process that extracts pulp logs and sawlogs for commercial sale to private enterprise. They play no part in reducing bushfire risk to life and property. Actually, the reverse is true: logging makes forests more prone to subsequent high-severity crown-consuming fires with associated risks to communities.




Read more:
Victoria’s logged landscapes are at increased risk of bushfire


Given that a substantial proportion of the recent smoke over Melbourne and surrounding regional Victoria likely originated from logging burns, could that smoke be deemed industrial pollution? This is a valid question, given the serious health impacts associated with smoke pollution.

The ConversationLogging burns would not be needed (and a substantial amount of associated smoke not generated) if the forest had not been logged in the first place. It is imperative that government departments inform the public about the smoke pollution coming from logging operations, whose purpose is for private commercial gain.

Chris Taylor, Researcher, University of Melbourne and David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National University

This article was originally published on The Conversation. Read the original article.

Common products, like perfume, paint and printer ink, are polluting the atmosphere



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We need to measure the volatile compounds that waft off the products in our homes and offices.

Jenny Fisher, University of Wollongong and Kathryn Emmerson, CSIRO

Picture the causes of air pollution in a major city and you are likely to visualise pollutants spewing out of cars, trucks and buses.

For some types of air pollutants, however, transportation is only half as important as the chemicals in everyday consumer products like cleaning agents, printer ink, and fragrances, according to a study published today in Science.

Air pollution: a chemical soup

Air pollution is a serious health concern, responsible for millions of premature deaths each year, with even more anticipated due to climate change.




Read more:
Climate change set to increase air pollution deaths by hundreds of thousands by 2100


Although we typically picture pollution as coming directly from cars or power plants, a large fraction of air pollution actually comes from chemical reactions that happen in the atmosphere. One necessary starting point for that chemistry is a group of hundreds of molecules collectively known as “volatile organic compounds” (VOCs).

VOCs in the atmosphere can come from many different sources, both man-made and natural. In urban areas, VOCs have historically been blamed largely on vehicle fuels (both gasoline and diesel) and natural gas.

Fuel emissions are dropping

Thanks in part to more stringent environmental regulations and in part to technological advances, VOCs released into the air by vehicles have dropped dramatically.

In this new study, the researchers used detailed energy and chemical production records to figure out what fraction of the VOCs from oil and natural gas are released by vehicle fuels versus other sources. They found that the decline in vehicle emissions means that – in a relative sense – nearly twice as much comes from chemical products as comes from vehicle fuel, at least in the US. Those chemicals include cleaning products, paints, fragrances and printer ink – all things found in modern homes.

The VOCs from these products get into the air because they evaporate easily. In fact, in many cases, this is exactly what they are designed to do. Without evaporating VOCs, we wouldn’t be able to smell the scents wafting by from perfumes, scented candles, or air fresheners.

Overall, this is a good news story: VOCs from fuel use have decreased, so the air is cleaner. Since the contribution from fuels has dropped, it is not surprising that chemical products, which have not been as tightly regulated, are now responsible for a larger share of the VOCs.

Predicting air quality

An important finding from this work is that these chemical products have largely been ignored when constructing the models that we use to predict air pollution – which impacts how we respond to and regulate pollutants.

The researchers found that ignoring the VOCs from chemical products had significant impacts on predictions of air quality. In outdoor environments, they found that these products could be responsible for as much as 60% of the particles that formed chemically in the air above Los Angeles.

The effects were even larger indoors – a major concern as we spend most of our time indoors. Without accounting for chemical products, a model of indoor air pollutants under-predicted measurements by a whopping 87%. Including the consumer products really helped to fix this problem.




Read more:
We can’t afford to ignore indoor air quality – our lives depend on it


What does this mean for Australia?

In Australia we do a stocktake of our VOC emissions to the air every few years. Our vehicle-related VOC emissions have also been dropping and are now only about a quarter as large as they were in 1990.

Historical and projected trends in Australia’s road transport emissions of VOCs.
Author provided, adapted from Australia State of the Environment 2016: atmosphere

Nonetheless, the most recent check suggests most of our VOCs still come from cars and trucks, factories and fires. Still, consumer products can’t be ignored – especially as our urban population continues to grow. Because these sources are spread out across the city, their contributions can be difficult to estimate accurately.

We need to make sure our future VOC stocktakes include sources from consumer products such as cleaning fluids, indoor fragrances and home office items like printing ink. The stocktakes are used as the basis for our models, and comparing models to measurements helps us understand what affects our air quality and how best to improve it. It was a lack of model-to-measurement agreement that helped to uncover the VW vehicle emissions scandal, where the manufacturer was deliberately under-estimating how much nitrogen gas was being released through the exhaust.

If we can’t get our predictions to agree with the indoor measurements, we’ll need to work harder to identify all the emission sources correctly. This means going into typical Australian homes, making air quality measurements, and noting what activities are happening at the same time (like cooking, cleaning or decorating).




Read more:
Heading back to the office? Bring these plants with you to fight formaldehyde (and other nasties)


What should we do now?

If we want to keep air pollution to a minimum, it will become increasingly important to take into account the VOCs from chemical products, both in our models of air pollution and in our regulatory actions.

In the meantime, as we spend so much of our time indoors, it makes sense to try to limit our personal exposure to these VOCs. There are several things we can do, such as choosing fragrance-free cleaning products and keeping our use of scented candles and air fresheners to a minimum. Research from NASA has also shown that growing house plants like weeping figs and spider plants can help to remove some of the VOCs from indoor air.

The ConversationAnd of course, we can always open a window (as long as we keep the outdoor air clean, too).

Jenny Fisher, Senior Lecturer in Atmospheric Chemistry, University of Wollongong and Kathryn Emmerson, , CSIRO

This article was originally published on The Conversation. Read the original article.

Flying home for Christmas? Carbon offsets are important, but they won’t fix plane pollution



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Roey Ahram/Flickr, CC BY-NC-SA

Susanne Becken, Griffith University and Brendan Mackey, Griffith University

Australia is an important player in the global tourism business. In 2016, 8.7 million visitors arrived in Australia and 8.8 million Australians went overseas. A further 33.5 million overnight trips were made domestically.

But all this travel comes at a cost. According to the Global Sustainable Tourism Dashboard, all Australian domestic trips and one-way international journeys (the other half is attributed to the end point of travel) amount to 15 million tonnes of carbon dioxide for 2016. That is 2.7% of global aviation emissions, despite a population of only 0.3% of the global total.


Read more: Life in a post-flying Australia, and why it might actually be ok


The peak month of air travel in and out of Australia is December. Christmas is the time where people travel to see friends and family, or to go on holiday. More and more people are aware of the carbon implications of their travel and want to know whether, for example, they should purchase carbon offsets or not.

Our recent study in the Journal of Air Transport Management showed that about one third of airlines globally offer some form of carbon offsetting to their customers. However, the research also concluded that the information provided to customers is often insufficient, dated and possibly misleading. Whilst local airlines Qantas, Virgin Australia and Air New Zealand have relatively advanced and well-articulated carbon offset programs, others fail to offer scientifically robust explanations and accredited mechanisms that ensure that the money spent on an offset generates some real climate benefits.

The notion of carbon compensation is actually more difficult than people might think. To help explain why carbon offsetting does make an important climate contribution, but at the same time still adds to atmospheric carbon, we created an animated video clip.

Jack’s journey.

The video features Jack, a concerned business traveller who begins purchasing carbon credits. However, he comes to the realisation that the carbon emissions from his flights are still released into the atmosphere, despite the credit.

The concept of “carbon neutral” promoted by airline offsets means that an equal amount of emissions is avoided elsewhere, but it does not mean there is no carbon being emitted at all – just relatively less compared with the scenario of not offsetting (where someone else continues to emit, in addition to the flight).

This means that, contrary to many promotional and educational materials (see
here for instance), carbon offsetting will not reduce overall carbon emissions. Trading emissions means that we are merely maintaining status quo.

A steep reduction, however, is what’s required by every sector if we were to reach the net-zero emissions goal by 2050, agreed on in the Paris Agreement.


Read more: It’s time to wake up to the devastating impact flying has on the environment


Carbon offsetting is already an important “polluter pays” mechanism for travellers who wish to contribute to climate mitigation. But it is also about to be institutionalised at large scale through the new UN-run Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).

CORSIA will come into force in 2021, when participating airlines will have to purchase carbon credits for emissions above 2020 levels on certain routes.

The availability of carbon credits and their integrity is of major concern, as well as how they align with national obligations and mechanisms agreed in the Paris Agreement. Of particular interest is Article 6, which allows countries to cooperate in meeting their climate commitments, including by “trading” emissions reductions to count towards a national target.

The recent COP23 in Bonn highlighted that CORSIA is widely seen as a potential source of billions of dollars for offset schemes, supporting important climate action. Air travel may provide an important intermediate source of funds, but
ultimately the aviation sector, just like anyone else, will have to reduce their own emissions. This will mean major advances in technology – and most likely a contraction in the fast expanding global aviation market.


Read more: Friday essay: smile and stay thin – life as a 60s air hostess


Travelling right this Christmas

In the meantime, and if you have booked your flights for Christmas travel, you can do the following:

  • pack light (every kilogram will cost additional fuel)

  • minimise carbon emissions whilst on holiday (for instance by biking or walking once you’re there), and

  • support a credible offsetting program.

The ConversationAnd it’s worth thinking about what else you can do during the year to minimise emissions – this is your own “carbon budget”.

Susanne Becken, Professor of Sustainable Tourism and Director, Griffith Institute for Tourism, Griffith University and Brendan Mackey, Director of the Griffith Climate Change Response Program, Griffith University

This article was originally published on The Conversation. Read the original article.

Delhi suffers second smog crisis in 12 months, as wake-up calls go unheeded


Vijay Koul, CSIRO

A year ago Delhi was choking, as smog in the Indian capital soared to 16 times the government’s safe limit for particulate pollution. Now the same thing has happened again.

Levels of the most dangerous particles, called PM2.5, have once again reached last November’s levels: more than 700 micrograms per cubic metre in some parts of the city. Experts say that prolonged exposure to this level of pollution is equivalent to smoking more than two packs of cigarettes a day.

Just 12 months after the record-breaking pollution that should have been a major wake-up call, Delhi is again plunged into darkness. It is a big embarrassment that authorities were not better prepared for this year’s smog season.


Read more: As another smog season looms, India must act soon to keep Delhi from gasping


In July, I released a detailed analysis of the factors that cause Delhi’s November smog.

Based on data from India’s Central Pollution Control Board and from NASA, I concluded that Delhi’s record-breaking pollution in November 2016 was largely due to slow wind speeds and prevailing northerly winds, as well as Diwali fireworks, and the widespread practice of burning crop residues. Others, including the Delhi government, reported similar findings.

But this knowledge has not stopped it happening again, much to the frustration of Delhi residents who now face a second consecutive pollution-plagued winter.

Of course, the authorities do not control the wind speed or direction. But they can and should take steps to curb the other crucial factors.

Burning issue

In Haryana and Punjab states to the north of Delhi, farmers routinely burn their croplands after the summer harvest, ridding their fields of stubble, weed and pests and readying them for winter planting.

This agricultural event coincides with Diwali, India’s festival of lights, which features three or four nights of fireworks before and after the festival, in October or early November.

This series of NASA satellite images clearly shows the pollution plume moving across the landscape during the first two weeks of November. Red dots indicate live fires.

November 1.
NASA
November 8.
NASA
November 14.
NASA

These images show that crop burning is still continuing, especially in parts of Punjab. As the graph below shows, crop burning produced significant amounts of pollution from November 2, 2017, after an earlier pollution spike around October 20 due to Diwali.

https://datawrapper.dwcdn.net/ZHncI/1/

Other countries have taken measures to limit crop burning. In Australia, the Victorian state government strongly encourages farmers to retain crop stubble residues, although it allows sporadic burning. In some Canadian provinces, stubble burning is allowed by permit only.

There is no such legislation under consideration in India. But without a ban on crop burning, Delhi’s pollution woes are likely to continue.

It is high time that the government responded, before Delhi’s pollution gets even more out of hand. Particles in the PM2.5 size range can travel deep into the respiratory tract, reaching the lungs. Exposure to fine particles can cause short-term health effects such as eye, nose, throat and lung irritation, coughing, sneezing, runny nose and shortness of breath.

Exposure to fine particles can also affect lung function and worsen medical conditions such as asthma and heart disease. Studies have linked increases in daily PM2.5 exposure with increased respiratory and cardiovascular hospital admissions, emergency department visits and deaths. More than a million deaths in 2015 were attributed to India’s air pollution.

What governments and residents can do

There is a range of short- and long-term options to combat the problem.

Farmers in Haryana and Punjab should be banned from residue crop burning during October and November, and should be given financial compensation for the inconvenience.

Meanwhile, Delhi’s residents should consider driving less, either by carpooling or using public transport. The city’s authorities, meanwhile, could restrict the entry of polluting trucks and heavy-duty goods vehicles, gradually phase out and ultimately ban older vehicles, and increase parking charges or restrict families to a single car.

A reliable 24-hour power supply would help to reduce the reliance on heavily polluting diesel generators in offices and factories. Subsidies for cleaner fuels or electric or hybrid cars would also help.


Read more: Air pollution causes more than 3 million premature deaths a year worldwide


Authorities also have a duty to keep the public informed of pollution levels, through daily television, radio and social media updates, as well as pamphlets warning of the effects of air quality on health. On the worst days, schools should be closed and children and older people urged to stay indoors.

In the longer terms, a “green belt” could be planted around the city, to help soak up traffic-induced air and noise pollution.

The ConversationMany of these policies would involve significant upheaval. But Delhi needs action before it is too late. The alternative is to be plunged ever deeper into the murk.

Vijay Koul, Honorary fellow, CSIRO

This article was originally published on The Conversation. Read the original article.

Australia still lags behind in vehicle emissions testing



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Emissions from real-life urban driving can be much higher than advertised.
AMPG/Shutterstock.com

Zoran Ristovski, Queensland University of Technology and Nic Surawski, University of Technology Sydney

Australian cars are using 23% more fuel than advertised, according to a report from the Australian Automobile Association, which also claims that eco-friendly hybrid electric cars emit four times more greenhouse gas than the manufacturers advertise.

The report on real-world (that is, on-road) emission testing was commissioned by consultancy firm ABMARC to test 30 cars twice on Melbourne roads. The method used to measure both the emissions and the fuel consumption was a so-called Portable Emissions Measurement System (PEMS).


Read more: The VW scandal exposes the high tech control of engine emissions


They found that when compared to the laboratory limits, on-road vehicle NOx (a toxic gas pollutant) emissions were exceeded for 11 out of 12 diesel vehicles, and carbon monoxide (also a toxic gas) emissions were exceeded by 27% of tested petrol vehicles.

However, the key consideration here is the phrase “comparison to the laboratory limits” because on-road tests can’t directly be compared to the laboratory test limits, for several key reasons.

How are emissions from vehicles measured?

Australian Design Rules (ADR) stipulate that before introducing a new vehicle model on the market, every car or truck manufacturer in Australia has to test one new car in the laboratory.

This is done by placing the vehicle on a chassis dynamometer, connecting the exhaust to highly accurate emissions-measurement equipment, and driving the vehicle according to a strictly defined routine.

The chassis dynamometer simulates the load conditions that the vehicle would experience if it were driven on a road. In current practice, the New European Driving Cycle (NEDC) is used. This defines the speed of the vehicle and rate of acceleration for every second of the 20-minute test.

There is strict control of the testing protocol, with stipulations on how and when the gears should be changed, right down to minute details such as turning off the radio while the headlights are on. This strict control enables testers to compare the performance of different vehicles measured in different laboratories around the world.

However, these highly defined conditions have led to certain manufacturers enabling the car’s engine management system to recognise when it is being tested and to adopt and produce cleaner exhaust emissions. The most famous example of this is the recent VW scandal that affected millions of vehicles worldwide.

Even though the driving cycle has “new” in its name, NEDC was designed in the 1980s and today can be considered outdated.

Real Driving Emissions

To address these challenges, Real Driving Emissions (RDE) tests were developed. RDE tests measure the pollutants emitted by cars while driven on the road. To run a RDE test, cars are fitted with a Portable Emissions Measurement System (PEMS).

A PEMS is a complex piece of equipment that sits in the back of the car and monitors key pollutants emitted by the vehicle in real time as it is driven on the road.

These tests have proved extremely useful in highlighting some of the shortfalls of the laboratory tests. They can be run for much longer periods (several hours as compared with 15-30 minutes in the laboratory) and can give us information on long-term emission performance of the vehicles. They will not replace laboratory tests, but can provide additional information.

RDE requirements will ensure that cars deliver low emissions during on-road conditions. In 2021, Europe will become the first region in the world to introduce such complementary on-road testing for new vehicles.

RDE tests still face several unresolved challenges. The first is that the PEMS are still being developed and are not as accurate as the lab measurement equipment. The second, and more important, is the variability that one encounters while driving in real-world road conditions.

In order to compare the RDE test results with the laboratory-based standards a “conformity factor” is defined as a “not to exceed limit” that takes into account the error of measurements. This error is due to the PEMS equipment being less accurate, the variability in road conditions and driving behaviour, and thus the fact that the RDE tests will not deliver exactly the same results for each run.

A conformity factor of 1.5 would mean that the emissions measured by the PEMS in an RDE test should not exceed the standard NEDC test by more than a factor of 1.5. This is exactly the value that European Union legislators want to introduce – but not before 2021.

Australia is years behind

Australia remains years behind the European Union when it comes to vehicle emission standards.

The Euro emissions standards define the acceptable limits for exhaust emissions of new vehicles sold in the EU. Australia introduced the Euro 5 emission standards in 2016 as compared to Europe, which introduced these in 2009. At that time EU abolished the Euro 5 standard for already new ones in 2015.


Read more: Australia’s weaker emissions standards allow car makers to ‘dump’ polluting cars


Australia needs to upgrade to meet Euro 6 standards in order to provide effective detection of new vehicles. These include measures such as remote sensing as part of a vehicles road-worthiness assessment. This would help to ensure the maintenance status of vehicles and deliver compliance with Euro 6 RDE legislation.

What the Australian Automobile Association report highlights most of all is that the in-use vehicles (whether or not they are hybrid vehicles), many of which fall under the Euro 5 standard (or older), have almost all failed emission tests.

The ConversationUntil Australia updates our vehicle testing regimes to meet international standards, it will remain extremely difficult for Australians who want to buy an energy-efficient vehicle to make an informed purchasing decision.

Zoran Ristovski, Professor, Queensland University of Technology and Nic Surawski, Lecturer – Air Quality/Vehicle Emissions, University of Technology Sydney

This article was originally published on The Conversation. Read the original article.

Australia emits mercury at double the global average


Robyn Schofield, University of Melbourne

A report released this week by advocacy group Environmental Justice Australia presents a confronting analysis of toxic emissions from Australia’s coal-fired power plants.

The report, which investigated pollutants including fine particles, nitrogen oxides and sulfur dioxide, also highlights our deeply inadequate mercury emissions regulations. In New South Wales the mercury emissions limit is 666 times the US limits, and in Victoria there is no specific mercury limit at all.

This is particularly timely, given that yesterday the Minamata Convention, a United Nations treaty limiting the production and use of mercury, entered into force. Coal-fired power stations and some metal manufacturing are major sources of mercury in our atmosphere, and Australia’s per capita mercury emissions are roughly double the global average.


Read more: Why won’t Australia ratify an international deal to cut mercury pollution?


In fact, Australia is the world’s sixteenth-largest emitter of mercury, and while our government has signed the Minamata convention it has yet to ratify it. According to a 2016 draft impact statement from the Department of Environment and Energy:

Australia’s mercury pollution occurs despite existing regulatory controls, partly because State and Territory laws limit the concentration of mercury in emissions to air […] but there are few incentives to reduce the absolute level of current emissions and releases over time.

Mercury can also enter the atmosphere when biomass is burned (either naturally or by people), but electricity generation and non-ferrous (without iron) metal manufacturing are the major sources of mercury to air in Australia. Electricity generation accounted for 2.8 tonnes of the roughly 18 tonnes emitted in 2015-16.

Mercury in the food web

Mercury is a global pollutant: no matter where it’s emitted, it spreads easily around the world through the atmosphere. In its vaporised form, mercury is largely inert, although inhaling large quantities carries serious health risks. But the health problems really start when mercury enters the food web.

I’ve been involved in research that investigates how mercury moves from the air into the food web of the Southern Ocean. The key is Antartica’s sea ice. Sea salt contains bromine, which builds up on the ice over winter. In spring, when the sun returns, large amounts of bromine is released to the atmosphere and causes dramatically named “bromine explosion events”.

Essentially, very reactive bromine oxide is formed, which then reacts with the elemental mercury in the air. The mercury is then deposited onto the sea ice and ocean, where microbes interact with it, returning some to the atmosphere and methylating the rest.

Once mercury is methylated it can bioaccumulate, and moves up the food chain to apex predators such as tuna – and thence to humans.

As noted by the Australian government in its final impact statement for the Minamata Convention:

Mercury can cause a range of adverse health impacts which include; cognitive impairment (mild mental retardation), permanent damage to the central nervous system, kidney and heart disease, infertility, and respiratory, digestive and immune problems. It is strongly advised that pregnant women, infants, and children in particular avoid exposure.


Read more: Climate change set to increase air pollution deaths by hundreds of thousands


Australia must do better

A major 2009 study estimated that reducing global mercury emissions would carry an economic benefit of between US$1.8 billion and US$2.22 billion (in 2005 dollars). Since then, the US, the European Union and China have begun using the best available technology to reduce their mercury emissions, but Australia remains far behind.

But it doesn’t have to be. Methods like sulfur scrubbing, which remove fine particles and sulfur dioxide, also can capture mercury. Simply limiting sulfur pollutants of our power stations can dramatically reduce mercury levels.

Ratifying the Minamata Convention will mean the federal government must create a plan to reduce our mercury emissions, with significant health and economic benefits. And because mercury travels around the world, action from Australia wouldn’t just help our region: it would be for the global good.


The ConversationIn an earlier version of this article the standfirst referenced a 2006 study stating Australia is the fifth largest global emitter of mercury. Australia is now 16th globally.

Robyn Schofield, Senior Lecturer for Climate System Science and Director of Environmental Science Hub, University of Melbourne

This article was originally published on The Conversation. Read the original article.