Trade-offs: What’s good for the climate may not be good for the air


This article is part of our special report Air Quality 2013.

SPECIAL REPORT / From wood stoves to diesel engines, the European Union has promoted fossil fuel alternatives and technology to help meet its obligations to reduce carbon dioxide emissions blamed for climate change. But these are also contribute to dirty air, leaving regulators to figure out some legislative repair work.

Some efforts appear to be paying off. In a new report, the European Environment Agency (EEA) says the EU’s greenhouse gas emissions fell 3.3% in 2011 and were 18.4% below 1990 levels. That would put the EU well on its way of achieving a 20% reduction from 1990 levels by the end of this decade.

The Eurostat statistical agency, meanwhile, reported that carbon dioxide (CO2) emissions fell 2.1% in 2012 after declining 4.1% a year earlier.

But numbers on carbon emissions aren’t necessarily good news for air quality – the focus of the EU’s Green Week this week.

A ‘major’ environmental problem

The EU’s achievements mean little while the rest of the world still pumps out record levels of carbon, and Europe’s methods for cutting greenhouse gases come with side effects, including higher emissions of nitrogen oxides (NOx), particulate matter (PM), ground-level ozone (O3), soot and sulphur that have both short- and long-term effects on human health.

“Air pollution remains one of the major environmental problems in Europe, affecting health and well-being of European citizens,” the EEA says in a new report on the impact of pollution on human health.

Air pollution was ranked as one of the top-10 risk factors for health globally, according to a global review of the burden of diseases published in December last year by the British medical journal The Lancet.

According to the study, over 430,000 premature deaths and over 7 million years of healthy life were lost across Europe in 2010 from exposure to fine particulate matter (PM2.5), with 166,000 premature deaths in Western Europe, 95,000 deaths in Central Europe, and 169,000 deaths in Eastern Europe, which includes Russia.

“Everyday exposure to outside air pollution in Europe is now recognised as one of the big factors affecting our health,” said Anne Stauffer, deputy director of Health and Environment Alliance (HEAL). “For the first time, the Global Burden of Disease assessment has ranked an environmental factor among the more widely discussed ‘life-style’ risk factors, such as tobacco and alcohol.”

Trade offs

Markus Amann, an expert on air pollution and greenhouse gases, said European policies show there are trade-offs in reducing greenhouse gases. “Ill-designed climate policies can result in higher particulate matter emissions,” he told a recent air quality conference in Brussels.

Amann, who works at the International Institute for Applied Systems Analysis in Austria, mentioned support for diesel engines as a case in point.

While diesel engines were promoted in Europe for their lower carbon emissions, they are blamed for stubbornly high levels of gases like nitrogen oxides (NOx) that contribute to ozone and acid raid.

Technological advances using advanced selective catalytic reduction (SCR) of NOx in vehicles, industrial smokestacks and ships are now required or are being phased in under EU and international standards to help deal with the problem. The technology can cut NOx emissions by as much as 90%, yet because older vehicles and some industrial plants are exempt, it could be years before the benefits of these technologies are realised.

Another example are biofuels and biomass, which have been promoted though European policies, including the Renewable Energy Directive, as part of the bloc’s carbon-cutting efforts. Yet their impact is far from benign.

Spurred by a combination of concerns over high food prices and doubts about the climate benefits of plant-based vehicle fuels, the European Commission last October made a U-turn on its policies that set targets to encourage the use of ethanol and biodiesel.

Where there’s smoke, there’s pollution

Mark Lawrence, the scientific director of the Institute for Advanced Sustainability Studies (IASS) in the German city of Potsdam, says biomass is considered green and advertised as such.

“If you think about the grey, brown and black smoke plumes above chimneys, you will see that this is not so green,” Lawrence told the science conference co-sponsored by his institute.

“But probably nobody I’ve talked to in the public is aware of the pollution that comes out of their chimneys. They are aware of the smoke that comes out, but they think it’s something that is just an irritant to their neighbours.”

Wood stoves are considered climate friendly because they emit relatively little carbon, but they contribute to air quality problems because the produce black carbon – an ingredient of soot – and NOx, which health officials say contribute to respiratory and cardiovascular problems, and environmental campaigners say contribute to ozone and affects plants and wildlife when they mix with rain to produce acidic deposits.

Lawrence was among the speakers at the conference on air quality and climate change, held on 21 May in Brussels, who pointed to the often divergent policies where efforts to combat climate change without considering the effect on air quality.

“If the policies are enforced, I think they are adequate to meet the limit values. With the human health concerns, science tells us that there are no thresholds, so they benefit from reducing it to very low concentrations.”

Scandinavian countries in general have been leaders in reducing CO2 emissions, and in using biomass for heating and energy, but they also exceed the Air Quality Directive’s annual mean value of NOx, which is 30 micrograms per cubic metre.

NOx emissions decline

Overall, NOx emissions have fallen since the 1990s, though at a much slower pace than other leading pollutants. When exposed to solar radiation, NOx reacts with other chemicals and gases to form ozone, which is harmful to humans and ecosystems and acts as a greenhouse gas. It also mixes with rain and is carried through the air, affecting areas well beyond its source of emission.

Health and environmental experts point to another culprit in NOx and soot pollution: biomass, or the use of wood and plant waste for home and water heating. Figures show that about half of the EU’s renewable energy targets are set to be achieved through the use of biomass.

Wood stoves, which are billed as a renewable energy and have grown in popularity across Scandinavia and in Central Europe, produce soot and high levels of NOx, black carbon – fine particulates that create soot – that are culprits in ground-level pollution and acid rain. Black carbon also contributes to climate change.

Experts at the Brussels conference said more effort needs to be put into coordinating climate and pollution policies to avoid the policies that address one problem but may create another.

IEA sees stalled progress

But Europe’s climate and pollution efforts, no matter how divergent, still put it ahead of other regions of the globe. The International Energy Agency reported recently that CO2 emissions have changed little since 1990, despite regulatory efforts and the rise in renewable energy production.

“The drive to clean up the world’s energy system has stalled,” IEA Executive Director Maria van der Hoeven said when the Paris-based organisation released its clean energy monitoring report. “Despite much talk by world leaders, and despite a boom in renewable energy over the last decade, the average unit of energy produced today is basically as dirty as it was 20 years ago.”

“As world temperatures creep higher due to ever-increasing emissions of greenhouse gases like carbon dioxide – two thirds of which come from the energy sector – the overall lack of progress should serve as a wake-up call,” van der Hoeven said.

“We cannot afford another 20 years of listlessness. We need a rapid expansion in low-carbon energy technologies if we are to avoid a potentially catastrophic warming of the planet, but we must also accelerate the shift away from dirtier fossil fuels.”

Environment Commissioner Janez Poto?nik, kicking off Green Week in Brussels, said: "Air pollution is often invisible, but its effects are very real. When air quality is poor we pay a heavy price: citizens' lives are lost, medical costs are high, and working days are lost to illness. Green Week provides an important platform where policymakers, representatives from local communities and NGOs, public authorities and businesses can exchange ideas on how improve the air we breathe – we are constantly open to suggestions on how to improve our current legislation."

Markus Amann, an expert on air pollution and greenhouse gases at the International Institute for Applies Systems Analysis in Austria, told EURACTIV that if EU polices on nitrogen oxides, or NOx, emissions are enforced, “they are adequate to meet the limit [health] values. With the human health concerns, science tells us that there are no thresholds, so they benefit from reducing it to very low concentrations.”

The International Energy Agency – which identifies biomass as a sustainable and low-carbon energy source – estimates that bioenergy accounts for about 10% of primary energy supply and forecasts that the largest demand by 2013 will be in the European Union. The Paris-based organisation’s World Energy Outlook projects that industrial and home heating will account for half of demand in the EU.

In the world’s advanced countries, wood and other bioenergy is second only to wind energy among renewable energy sources, the IEA report shows.

Yet health officials say the downside of burning wood and plant waste from agriculture produces high levels of NOx, soot and fine particulates that are linked to human health problems, including respiratory and cardiovascular disease. In 2012, a World Health Organisation study raised concerns about the potentially toxic effects of black carbon and other particulate matter produced from the combustion, including biomass.

Black carbon is harmful to humans and ecosystems at the ground level, and causes warming in the upper atmosphere.

  • 4-7 June: EU Green Week
  • 4-7 June: EU Cleaner Air for All conference in Brussels
  • 5 June: World Environment Day
  • 2013: 'Year of Air' as declared by Environment Commissioner Janez Poto?nik.

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