Where does air pollution come from?
The main sources of air pollution, according to the British Lung Foundation:
“In towns and cities, the main source of air pollution is road transport. Diesel and petrol vehicles create pollutants…friction of brakes and tyres on the road also…Other sources of air pollution include burning fuel in houses for heating or cooking, emissions from power generation, industrial processes, agriculture…(also) bonfires and firework displays… can result in temporary increases in particulate pollution.”
Additionally, “Air pollution can travel long distances and can affect areas far away from where it was created. UK pollution levels can even be affected by pollution sources outside the country.”
What might a Bristol Clean Air Policy look like?
Reduce car journeys
Reduce number of diesel engine cars on roads
Reduce number of petrol engine cars on roads
Reduce other pollutants (residential, industrial, agricultural, car tyre friction, pollutants that travel)
Measures to decrease pollutants from across UK and agreements with other countries.
What facilitates this?
Ease of use of alternative options like public transport, electric vehicles – cost and accessibility
In turn, this requires infrastructure:
Public transport – more public transport journeys available that are also quicker and cheaper, better and quicker road network) and, possibly, subsidies.
Electric vehicles – more charging points, support of industry and technology which again may involve subsidies
Road network – ease of transition, minimum speed, minimal stop/start
In the face of all these requirements, the Councils’ Bristol Clean Air Policy looks like this:
- To reduce diesel by charging diesel cars in a small central area
- To reduce diesel by charging buses/taxis in a wider zone
On the face of it, this seems a good place to start. But what are the actual likely results of this strategy (strategy is a generous term to describe a couple of measures which feel a little like a knee-jerk reaction)?
In relation to a central no diesel zone, the alternative choices by drivers are to reroute or pay the charges. if everyone takes one of these options, there is no actual reduction in pollutants in city; city centre pollutants may be reduced, but the emissions are simply displaced elsewhere in the city.
And for the wider charging zone, the alternative choices are the same – reroute or pay the charges – which means the results will be the same as above.
So, this tactic only works if it reduces the number of journeys. If it merely displaces them, it is completely ineffectual.
As for the rest of the potential actions:
- Reduce car journeys – only if the above works
- Reduce petrol – no proposal
- Reduce other pollutants – no proposal
- Measures and agreements outside the city – no proposal
A proper strategy should include all the above issues, that way there is a chance of attacking causes, not just symptoms.
Anyone driving through and around Bristol regularly, could be forgiven for thinking that a lot of council action in the city of Bristol seems to revolve round making car journeys as horrible as possible. The point being, presumably, to encourage people to use public transport, walk or cycle.
Has this worked?
Well, to some extent, yes. The number of bus journeys in the city increased by 44% between 2012/13 and 2017/18, according to the Councils own figures. And numbers of people cycling to work increased by 64% between 2011 and 2018
However, the population in Bristol has grown by 11.7% since 2008 and, on current trends, could increase by 21% over the next 25 years. And the number of cars rose by over 25,000 between 2001 and 2011. Of the British Core Cities, Bristol is second highest in this regard.
Additionally, the average car speed in 2018 is 15.3 miles mph, lower than the previous year, while 80% of Bristolians feel congestion is a problem in their area.
There is a direct correlation between congestion in cities and air pollution and nose to tail traffic can create four times more pollution than free-flowing traffic, as this report shows:
“When speeds fall from 16kpmh to 12 kmph there is almost a 10% increase in NOx from diesel cars and vans, and a 25% and 27% increase for buses and trucks…”
The common perception is that this is about roadworks, traffic calming measures and so on. However, the same report shows that the “overwhelming cause of congestion… is that there are too many vehicles on the road.”
A possible future
Short term – reduce number of diesel cars by swapping for petrol engines, for an immediate effect, which might involve incentivising change over (scrappage scheme, subsidies) and eliminating from certain areas if this can be proved not to simply displace effect.
Medium term – reduce number of petrol cars by further developing and subsidising electric car manufacture and purchase, increasing number of charging points
Medium term – to reduce number of cars overall with further improvements to public transport (in terms of cost and convenience) and better protection and environment for cyclists and walkers
Medium to long term – continuous improvements to residential, commercial, industrial and agricultural pollution; includes building self-sustaining energy homes, rainwater harvesting, green energy, recycling, reusing, reducing waste, etc.
Medium to long term – continuous global agreement and activity to reduce pollution
No one, simple idea is going to fix this problem. It requires systems thinking, big picture analysis and a comprehensive, long term, sustainable strategy.
Additionally, education has an important role to play. It is easy for us all to think that one tiny change in our habits, which might be inconvenient or cost a little more, is going to make any difference overall.
Naturally and obviously, for just one person making a change this would be true. But lots of individuals making changes begins to add up. The council and government cannot be blamed for all our ills. We have a responsibility also to make the world a better place for our children’s, children’s, children.
British Lung Foundation: Where does air pollution come from, accessed 10.11.2019
Bristol City Council: State of Bristol, Key Facts 2019, accessed 10.11.2019
Greener Journeys, Tackling Pollution and Congestion, 15 June 2017, accessed 10.11.2019