One of the achievements of Boris Johnson as Mayor of London is that the air in the capital is cleaner than it was under Ken Livingstone.

It is under Boris that more trees have been planted, cycling has been encouraged, buses are belching out lower levels of pollution, and the taxis are cleaner.

Boris announced to the London Assembly:

We have cut emissions of PM10s and PM2.5 by 15 per cent. We have cut emissions of nitrous oxides (NOx). We are only in breach of European Union standards on NOx and we have cut NOx by 20%.

Since I have been Mayor, the number of Londoners living in areas exceeding legal limits has halved from 3.6 million to 1.7 million.

Then Boris teased the Lib Dems over the recent Kingston Council results:

I notice that we have, for instance, one borough that neither completed its statutory air quality reports under the Environment Act 1995, nor had air quality monitoring stations and also turned down £74,000 from my air quality fund because they did not want to be a Cleaner Air Borough.

That was Kingston where the Liberal Democrats lost control to the Conservatives.

It shows what Liberal Democrats do when they get in to power.  They babble on about air quality.

When they are actually in charge of running a council…

Then a Lib Dem London Assembly member Stephen Knight started heckling about what a serious matter poor air quality is “which 4,000 plus Londoners a year are dying of”. How dare the Mayor be “flippant”? But if improving air quality is important, if it saves lives, then it should not be “above” politics. It should be a central political issue. It should be there right in the middle of the vigorous political argument.

Conservatives should be clear that this is our issue. It is right to favour making people richer by championing free market policies to release the process of wealth creation. There is no reason why that should not be compatible with cleaner air. Technological innovation is an ally of both.

It is also quite proper to maintain a rigorous scepticism towards claims of global warming – the more we have bullying demands from establishment vested interests to close down the debate on this matter the more important for dissenting voices to be heard.

What cannot be disputed is that clean air is a good thing. It is an environmental objective that should be shared by all. We should be pleased that Conservatives – rather than socialists or Lib Dems – are the most effective in delivering it.