Dirty Diesel

Why is diesel now bad news?

The mayor of Paris wants the city to become ‘semi-pedestrianised’

The Mayor of Paris Anne Hidalgo wants to ban diesel cars and the pollution they bring from the streets of the French capital. But not long ago, diesel engines were thought to be environmentally friendly. What could have gone wrong?

Opinion on diesel cars has swung widely over the years.

Diesel is a more efficient fuel than petrol, but in the past diesel engines were often noisy and dirty.

Then, with growing concerns over climate change, car manufacturers were urged to produce cleaner, quieter diesel cars to capitalise on their extra fuel efficiency.

The cars were fitted with a trap to catch the particles of smoke associated with the fuel. Several governments rewarded the manufacturing improvements by incentivising the purchase and use of diesel cars.

But the policy has backfired.

Going into reverse

First, there have been problems with the particle traps – some drivers have removed them because they sometimes don’t work properly unless the car is driven hot.

Second, the diesels are still producing nitrogen dioxide (NO2), which irritates the lungs of people with breathing problems. Diesels make several times more NO2 than petrol cars.

Now, in order to meet European air pollution laws, politicians are being forced into an embarrassing U-turn, telling drivers that they’ve decided they don’t much like diesels after all.

MPs in the UK have mooted a scrappage scheme for diesel cars, while the mayor of Paris has called for a ban.

Several European nations are currently in breach of EU clean air laws.

The EU’s NO2 limit was exceeded at 301 sites in 2012, including seven in London. The concentration on Marylebone Road was more than double the limit.

Districts in Athens, Berlin, Brussels, Madrid, Paris, and Rome are also exceeded the ceiling.

Not just carbon: Key pollutants for human health

• Particulate matter (PM): Can cause or aggravate cardiovascular and lung diseases, heart attacks and arrhythmias. Can cause cancer. May lead to atherosclerosis, adverse birth outcomes and childhood respiratory disease. The outcome can be premature death.
• Ozone (O3): Can decrease lung function and aggravate asthma and other lung diseases. Can also lead to premature death.
• Nitrogen oxides (NO2): Exposure to NO2 is associated with increased deaths from heart and lung disease, and respiratory illness.
• Polyaromatic hydrocarbons (PAHs), in particular benzo a-pyrene (BaP): Carcinogenic.

Politicians are now scurrying to persuade the courts that they are obeying an EU demand to clean up the air as soon as possible.

Source: BBCNews Read more

The great diesel scandal

How cheap fuel is choking our cities

Diesel’s popularity with motorists has surged, but its green image was an illusion. Now concern is growing over the damage caused by emissions, with children particularly vulnerable

The diesel and the damage done … particulates are one of the worst offenders in air pollution. Photograph: Peter Macdiarmid/Getty Images

Stand at a busy road junction on a bright day and chances are you will see it: a Wacky Races cloud of black smoke left hanging in the air after a car pulls away. These clouds are actually particles of soot – partially burnt fuel from diesel engines – and they are arguably the worst environmental menace facing city-living Britons – and children in particular.

Diesel vehicles have enjoyed a surge in popularity on our roads, rising from less than a quarter to more than half of all cars sold in the last five years. In the recent past, they were even touted as more environmentally friendly than petrol vehicles, because they burn less fuel and so can produce, overall, less CO2. This green image, however, was always an illusion: diesel engines burn fuel less cleanly than petrol-driven models, resulting in a large excess of particulates – the visible clumps of soot left behind in the exhaust fumes.

Particulates are one of the worst offenders in air pollution because they damage the lungs when inhaled. “It has been known for a long time that diesel particles are harmful, and the links to lung cancer have been widely published,” says Penny Woods, chief executive of the British Lung Foundation. “Along with other major factors such as poor diet and smoking, diesel levels in a large city like London have been associated with significant health problems.” For children, especially, this can cause a permanent stunting of lung growth. And the picture may be even worse than current studies show: “There is a growing consensus in the medical community that diesel particulate emissions are more dangerous to health, particularly lung health, than previously thought,” adds Woods.

Yet despite our growing knowledge of the problem, the coalition’s policies – which follow on from equally harmful policies under the previous government – still favour diesel over petrol, and motorists continue to respond by opting for diesel in the showroom and at the pump. Diesel is taxed at exactly the same rate as petrol, a situation that the Treasury argues is fair and shows no favouritism between the fuels. The problem with this argument is that diesel cars travel further on a gallon of fuel than their petrol-driven counterparts, so the tax per mile is much lower.

The answer, according to a growing number of experts, is to tax diesel more heavily and regulate its use more strictly. The British Lung Foundation would firmly support such measures, says Woods. Simon Birkett, founder of Clean Air in London, also supports higher taxes, as does the environmental group Client Earth, and the RAC Foundation, while Friends of the Earth wants a fuel-tax review and Greenpeace says higher taxes in urban areas may be the best approach.

Source: TheGuardian Read more