Even for an air pollution historian like me, these past weeks have been a shock



Throughout history, Australian bushfires have spread smoke over our cities. But this time it’s different.
David Mariuz/AAP

Nancy Cushing, University of Newcastle

Smoke from this season’s bushfires has turned the sun red, the moon orange and the sky an insipid grey. It has obscured iconic views tourists flock to see. Far more than an aesthetic problem, it has forced business shutdowns, triggered health problems and kept children indoors for weeks.

City dwellers in southeast Australia have been forced to take a crash course in the finer points of air pollution. We’ve learned about the dangers of inhaling tiny PM2.5 particles (those 2.5 microns or fewer in diameter). We’ve learned that only a close-fitting P2 mask will do much to protect us.

Still, we wear disposable paper masks and hold handkerchiefs to our faces, hoping any amount of filtering is helpful.

A police officer wears a mask while on duty at Parliament House in Canberra.
NARENDRA SHRESTHA/AAP

Even for an historian of air pollution like me, this situation is a shock. It is not the first time Australia’s major cities have been shrouded in bushfire smoke. But the terrible air quality is unmatched in terms of severity, duration and extent.

Historically, air pollution from smoke was considered outside human control and not subject to regulation. But these bushfires are clearly linked to global warming, for which government, corporations and individuals are responsible. It’s time to rethink the way we protect air quality.

The history of smoke

In recent weeks, apps such as AirVisual have confirmed what we city dwellers can already see and smell: since the fires on the north coast of NSW began in late October, our air quality has plummeted.

The New South Wales government’s Air Quality Index data has shown that since late October, days when the index was higher than 100 – signalling exposure is unhealthy – have outnumbered clear days in Sydney, Newcastle and the Illawarra.

Smoke emissions from the Australian bushfires from 1 December 2019 to 4 January 2020.

Index readings above 2,550 have been recorded in Sydney, while the Monash monitoring site in Canberra reached a choking 5,185 at 8pm on New Year’s Day.

Bushfire smoke has affected the cities of NSW and the Australian Capital Territory in the past. In late January 1926, when Canberra was just emerging as a city, a thick haze of smoke sat over the site. Fires came within metres of Yarralumla, the residence which, the following year, would become home to the Governor-General.

In several years in the mid 1930s, bushfires burning to the north of Sydney left the city air thick with smoke. In October 1936, bushfire smoke forced a motor liner arriving from Hong Kong to warily enter the harbour sounding its siren, because it was invisible to signallers on South Head.

A New Zealand pilot, flying into Sydney from Longreach the following month, had to fly blind in “great clouds of dense smoke” covering much of NSW. In 1939, Canberra was covered by what visiting writer HG Wells described as a “streaming smoke curtain”.




Read more:
How wildfire smoke affects pets and other animals


In the summer of 1944, Sydney was again enveloped in a smoke haze, this time from fires in the Blue Mountains and (later Royal) National Park in November. Photographs published at the time show the Sydney Harbour Bridge barely visible through dust and smoke at midday. The ongoing fires were blamed for an increase in diseases of the ears, nose and throat, and for cases of influenza and pneumonia, leading to a shortage of hospital beds.

A satellite image showing fires burning on Australia’s east coast.
NASA EARTH OBSERVATORY

In November 1951, all of NSW was said to be blacked out by bushfire smoke. In Sydney on the worst days, records show all four of the city’s airfields were closed because of “smoke-fog”.

A hazy legal framework

In each of these episodes, bushfire smoke disrupted transport, commerce, health and the enjoyment of the urban environment. But even as other forms of air pollution began to be regulated, smoke from bushfires escaped legislative attention.

What was understood as air pollution were the unwanted byproducts of industrial processes, whereas bushfire smoke was viewed as natural.




Read more:
Pregnant women should take extra care to minimise their exposure to bushfire smoke


In NSW in 1866, an act based on British legislation restricted smoke from mills, distilleries and gas works. Further limitations on smoke production in built-up areas were included in later acts governing public health (1902), motor traffic (1909) and local government (1919).

After World War II Newcastle, the site of the country’s largest concentration of coal-burning heavy industry, began to pay closer attention to managing air quality. This pioneering work was given added urgency after 4,000 people died in heavy London smog in 1952.

A woman seen wearing a face mask as smoke haze from bushfires blankets Sydney.
JOEL CARRETT/AAP

In 1958, a NSW parliamentary committee delivered a report into smoke abatement. It did not mention recent issues with bushfire smoke, and also dismissed the impact of domestically produced smoke. The subsequent 1961 Clean Air Act focused on air pollution from industry, transport and power generation.

Air pollution legislation continued to evolve in following decades, targeting motor vehicle emissions in the 1970s, backyard burning of waste in the 1980s, and wood fires used to heat homes in the 1990s.

These measures have been successful. A 2006 study found that between 1998 and 2003, on the limited occasions when standards for PM10 in six Australian cities were exceeded, the main sources were not industry or transport, but dust storms and bushfires (with the exception of Launceston, where heating fires were the main contributor).

A young man jumps from a rock in Sydney during smoke haze.
Steven Saphore/AAP

Looking ahead

Today, bushfire smoke is excluded from air quality regulations, despite its obvious role in pollution. It is still considered natural, and beyond human control.

However the link between the current fires and human-caused climate change, long predicted by climate scientists, suggests this exemption is no longer valid.




Read more:
Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do


As the Australian National University’s Tom Griffiths has written, the current fires in some ways repeat patterns of the past. But “the smoke is worse, more widespread and more enduring”.

When Australia begins the recovery from these fires, our business-as-usual approach requires a rethink. Measures to protect air quality should be a major part of this.

It is time that corporations, governments and societies which contribute to global heating be held to account for more frequent, intense and widespread bushfires, and the smoke which billows from them.The Conversation

Nancy Cushing, Associate professor, University of Newcastle

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

Climate explained: seven reasons to be wary of waste-to-energy proposals



Many developed countries already have significant waste-to-energy operations and therefore less material going to landfill.

Jeff Seadon, Auckland University of Technology


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

I was in Switzerland recently and discovered that they haven’t had any landfill since the early 2000s, because all of their waste is either recycled or incinerated to produce electricity. How “green” is it to incinerate waste in order to produce electricity? Is it something New Zealand should consider, so that 1) we have no more landfill, and 2) we can replace our fossil-fuel power stations with power stations that incinerate waste?

Burning rubbish to generate electricity or heat sounds great: you get rid of all your waste and also get seemingly “sustainable” energy. What could be better?

Many developed countries already have significant “waste-to-energy” incineration plants and therefore less material going to landfill (although the ash has to be landfilled). These plants often have recycling industries attached to them, so that only non-recyclables end up in the furnace. If it is this good, why the opposition?

Here are seven reasons why caution is needed when considering waste-to-energy incineration plants.




Read more:
Why municipal waste-to-energy incineration is not the answer to NZ’s plastic waste crisis


Stifling innovation and waste reduction

  1. Waste-to-energy plants require a high-volume, guaranteed waste stream for about 25 years to make them economically viable. If waste-to-energy companies divert large amounts of waste away from landfills, they need to somehow get more waste to maintain their expensive plants. For example, Sweden imports its waste from the UK to feed its “beasts”.

  2. The waste materials that are easiest to source and have buyers for recycling – like paper and plastic – also produce most energy when burned.

  3. Waste-to-energy destroys innovation in the waste sector. As a result of China not accepting our mixed plastics, people are now combining plastics with asphalt to make roads last longer and are making fence posts that could be replacing treated pine posts (which emit copper, chrome and arsenic into the ground). If a convenient waste-to-energy plant had been available, none of this would have happened.

  4. Waste-to-energy reduces jobs. Every job created in the incineration industry removes six jobs in landfill, 36 jobs in recycling and 296 jobs in the reuse industry.

  5. Waste-to-energy works against a circular economy, which tries to keep goods in circulation. Instead, it perpetuates our current make-use-dispose mentality.

  6. Waste-to-energy only makes marginal sense in economies that produce coal-fired electricity – and then only as a stop-gap measure until cleaner energy is available. New Zealand has a green electricity generation system, with about 86% already coming from renewable sources and a target of 100% renewable by 2035, so waste-to-energy would make it a less renewable energy economy.

  7. Lastly, burning waste and contaminated plastics creates a greater environmental impact than burning the equivalent oil they are made from. These impacts include the release of harmful substances like dioxins and vinyl chloride as well as mixtures of many other harmful substances used in making plastics, which are not present in oil.




Read more:
Circular fashion: turning old clothes into everything from new cotton to fake knees


Landfills as mines of the future

European countries were driven to waste-to-energy as a result of a 2007 directive that imposed heavy penalties for countries that did not divert waste from landfills. The easiest way for those countries to comply was to install waste-to-energy plants, which meant their landfill waste dropped dramatically.

New Zealand does not have these sorts of directives and is in a better position to work towards reducing, reusing and recycling end-of-life materials, rather than sending them to an incinerator to recover some of the energy used to make them.

Is New Zealand significantly worse than Europe in managing waste? About a decade ago, a delegation from Switzerland visited New Zealand Ministry for the Environment officials to compare progress in each of the waste streams. Both parties were surprised to learn that they had managed to divert roughly the same amount of waste from landfill through different routes.

This shows that it is important New Zealand doesn’t blindly follow the route other countries have used and hope for the same results. Such is the case for waste-to-energy.

There is also an argument to be made for current landfills. Modern, sanitary landfills seal hazardous materials and waste stored over the last 50 years presents future possibilities of landfill mining.

Many landfills have higher concentrations of precious metals, particularly gold, than mines and some are being mined for those metals. As resources become scarcer and prices increase, our landfills may become the mines of the future.The Conversation

Jeff Seadon, Senior Lecturer, Auckland University of Technology

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

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



File 20180215 131000 1ie7l5j.jpg?ixlib=rb 1.1
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.

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



File 20171026 13327 1i52oqe.jpg?ixlib=rb 1.1
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.

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


Guang Zeng, National Institute of Water and Atmospheric Research and Jason West, University of North Carolina – Chapel Hill

Climate change is set to increase the amount of ground-level ozone and fine particle pollution we breathe, which leads to lung disease, heart conditions, and stroke. Less rain and more heat means this pollution will stay in the air for longer, creating more health problems.

Our research, published in Nature Climate Change, found that if climate change continues unabated, it will cause about 60,000 extra deaths globally each year by 2030, and 260,000 deaths annually by 2100, as a result of the impact of these changes on pollution.

This is the most comprehensive study to date on the effects of climate change on global air quality and health. Researchers from the United States, the United Kingdom, France, Japan and New Zealand between them used nine different global chemistry-climate models.

Most models showed an increase in likely deaths – the clearest signal yet of the harm climate change will do to air quality and human health, adding to the millions of people who die from air pollution every year.


Read more: Can we blame climate change for thunderstorm asthma?


Stagnant air

Climate change fundamentally alters the air currents that move pollution across continents and between the lower and higher layers of the atmosphere. This means that where air becomes more stagnant in a future climate, pollution stays near the ground in higher concentrations.

Ground-level ozone is created when chemical pollution (such as emissions from cars or manufacturing plants) reacts in the presence of sunlight. As climate change makes an area warmer and drier, it will produce more ozone.

Fine particles are a mixture of small solids and liquid droplets suspended in air. Examples include black carbon, organic carbon, soot, smoke and dust. These fine particles, which are known to cause lung diseases, are emitted from industry, transport and residential sources. Less rain means that fine particles stay in the air for longer.

While fine particles and ozone both occur naturally, human activity has increased them substantially.

The Intergovernmental Panel on Climate Change has used four different future climate scenarios, representing optimistic to pessimistic levels of emissions reduction.

In a previous study, we modelled air pollution-related deaths between 2000 and 2100 based on the most pessimistic of these scenarios. This assumes large population growth, modest improvements in emissions-reducing technology, and ineffectual climate change policy.

That earlier study found that while global deaths related to ozone increase in the future, those related to fine particles decrease markedly under this scenario.

Emissions will likely lead to deaths

In our new study, we isolated the effects of climate change on global air pollution, by using emissions from the year 2000 together with simulations of climate for 2030 and 2100.

The projected air pollutant changes due to climate change were then used in a health risk assessment model. That model takes into account population growth, how susceptible a population is to health issues and how that might change over time, and the mortality risk from respiratory and heart diseases and lung cancer.

In simulations with our nine chemistry-climate models, we found that climate change caused 14% of the projected increase in ozone-related mortality by 2100, and offset the projected decrease in deaths related to fine particles by 16%.

Our models show that premature deaths increase in all regions due to climate change, except in Africa, and are greatest in India and East Asia.

Using multiple models makes the results more robust than using a single model. There is some spread of results amongst the nine models used here, with a few models estimating that climate change may decrease air pollution-related deaths. This highlights that results from any study using a single model should be interpreted with caution.

Australia and New Zealand are both relatively unpolluted compared with countries in the Northern Hemisphere. Therefore, both ozone and fine particle pollution currently cause relatively few deaths in both countries. However, we found that under climate change the risk will likely increase.

The ConversationThis paper highlights that climate change will increase human mortality through changes in air pollution. These health impacts add to others that climate change will also cause, including from heat stress, severe storms and the spread of infectious diseases. By impacting air quality, climate change will likely offset the benefits of other measures to improve air quality.

Guang Zeng, Atmospheric Scientist, National Institute of Water and Atmospheric Research and Jason West, Associate Professor, Department of Environmental Sciences and Engineering , University of North Carolina – Chapel Hill

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