Hot weekend means people with lung or heart problems should avoid outdoor strenuous activity, warns Defra

Air pollution warnings have been issued with temperatures forecast to climb towards 27C (80F) in south-east England and the Midlands this weekend.

Mayors from Paris, Madrid and Athens say loophole in NOx emissions tests puts citizens’ health at risk

The mayors of 20 European cities including Paris, Madrid and Athens have attacked the European Union for allowing a loophole in diesel cars’ pollution limits, just months after the VW emissions scandal.

People are increasingly being warned about the dangers of diesel pollution, but how much are we actually exposed to? Tim Johns tried to find out.

Waiting for my train one day, standing on the concourse, it occurred to me that there seemed to be rather a lot of fumes coming from the idling diesel engines.

How much diesel pollution was I breathing in?

I decided to undertake an experiment for The Jeremy Vine Show on BBC Radio 2 to find out how much I was being exposed to on a daily basis, in different locations and on different modes of transport.

It is the greatest environmental hazard of the age. Nothing focuses our concern for the future more, divides rich and poor, exercises science, business, politicians, old and young. It is an existential threat, a generational battle. All political and financial resources must be concentrated on stopping climate change.

Humanity has witnessed unprecedented growth and prosperity in the past decades, with the size of the world economy more than tripling and population increasing by over 3 billion people since 1970. This growth, however, has been accompanied by environmental pollution and natural resource depletion. The current growth model and the mismanagement of natural assets could ultimately undermine human development.