Imagine painting a white wall red. Coat number one will make the white wall considerably redder. Coat two will make it a bit redder. Coat three might make a bit of difference. Further coats are unlikely to increase the redness of the wall. That’s how the physics of heat retention by CO2 works. We have passed the point where adding CO2 makes any material difference. 

That’s what we are doing Net Zero for in the United Kingdom. The clean air zones; Sadiq Khan’s ULEZ; the green initiatives; the fields given over to solar farms; the unsightly wind turbines; the misery for cabbies, hauliers and farmers; the cycle lanes; the freezing pensioners; the panicking children; the endless coverage in the media. 

All of it to eliminate 1% of our world’s human emissions of CO2 which in any case has a marginal effect, if any, on the temperature of the planet. 

Besides, CO2 is plant food. Pre industrial levels were around 280 parts per million. If it drops below 150 parts per million the plants will all die, and then we will all die. 

During the industrialisation of the planet since the mid eighteenth century mankind has increased it to 420 parts per million by burning fossil fuels and releasing the carbon that became trapped in coal and oil millions of years ago. The provision of cheap and reliable sources of fuel has underpinned the growth of modern civilisation. Thank goodness for mankind!

There remains, however, a scientifically controversial issue concerning acidification of the oceans’ surface layers and this requires careful observation of effects upon ocean biodiversity which are as yet not apparent.