Every time it rains, micro-particulates and the products of Fossil Fuels combustion are scrubbed out of the air: London 4pm on a dry summer's day is never as bad as Cairo at 10am. Believe me, Egypt is far, worse than any European city.When we burn Fossil Fuels, the form an emulsion of water, CO2, SO2, NOx and SOx. As the gases cool they form H2CO3, H2NO2/3, H2SO2/3 – Acid rain
Which falls and fertilises plant life. That form plant biomass.
Sucking the CO2 and the rest out of the air. No possible climate effect – as the gases are removed from the air, Falling as rain in the cold of the night. No increase of CO2 biological or physically possible: Global Warming the most stupid science un-idea ever.
Going into cities, drivers of petrol and diesel cars should turn on the water flow, so a fine ring of nozzle in the exhaust, forms a fine mist. To ensure the CO2 and NOx (Nitrous acids) falls as very slightly acid rain – and run into the sewers. Cars stationary with a running engine should also have the mist, to clean the air. And stop children breathing in CO2 etc..
And that will give London the cleanest air in the world. You refill the water store. At a garage, a stream. Or at night at home.