On reading ‘Seek out and evaluate many sources please!' by Bryan Johnson, (The Weekend Sun letters page, Friday November 25), I felt constrained to reply.

There's a phrase I picked up at an online techies' watering-hole: 'You may have your own opinions; you aren't permitted your own facts”. The question is not whether or not one can marshall any number of distinguished opinions; the question is, do those opinions stack up?

Arthur C Clarke, of the film ‘2001: A Space Odyssey' fame, once said that when an elderly distinguished scientist says something is impossible, he's bound to be wrong.

I don't care about the number of distinguished ‘climate change sceptics' aka ‘climate change deniers', nor for that matter, for their opinions.

The fact is and remains, that carbon dioxide is a greenhouse gas; in the quantities it has been pumped into the atmosphere for the past two centuries it is bound to have an effect; sea levels are rising and Florida and Bangladesh among other places are going to find themselves running out of land; and glaciers worldwide are shrinking. Sea level worldwide won't be greatly affected by the Arctic icecap shrinking; it's a different story altogether with the Antarctic icecap.

The existence of carbon dioxide was deduced from the fact it retained heat. And yes, they knew about its greenhouse effect as far back as 1966, when Harry Harrison wrote the SF novel ‘Make Room! Make Room!', later filmed in 1973 as ‘Soylent Green', starring no less than Charlton Heston and set in 2022. So do I believe the people who agree that 1+1=2 except when it impacts their pay-packets, or the sane folk?

Wesley Parish, Bellevue.