Friday, April 21 this year was rather special. It was the first whole day in the last 135 years that all the UK electricity was produced without burning any coal - not even a bucket full.

However it still wasn’t all CO2 free as natural gas produced over a third of our power needs, and its carbon emissions are still half those of coal. We should also recognise that most houses, some eighteen million, are heated by gas, and the majority use it for cooking.

It would be encouraging if the decline in coal use was a response to the problems caused by a warming, unstable climate, but it’s a raft of other reasons, mainly economic and health related. However, the end of coal use is a significant ambition, with 2025 being the government target, though Belgium managed it in 2013.

Since 1950 coal has faced clean air legislation, the phasing out of steam trains, the growth of central heating, North Sea oil and gas, nuclear energy, and finally the political problems and pit closures.

However the next important target will be when all our electricity is produced free from CO2 and that’s still a distant date, despite the progress in developing the various forms of renewable energy.

In 2015 just under half of our electricity was CO2 free, with nuclear providing 21 per cent and solar, wind, tidal, wave, hydro electric power, and biomass at 25 per cent, a quarter of our electricity.

However this is not as quite as encouraging as might first appear, as the figure only includes power and omits all the electricity used in transport, and heating for both space and water. When this is included our use of CO2 free renewable electricity is just over eight per cent.

The 2020 EU target of 15 percent must be in doubt post Brexit.