I seem to be learning something new almost every day and this includes words that I don’t think I have ever seen before. Dr Jim Hansen, the highly-reputable NASA climate scientist, used the word ‘irrefragable’ and my dictionary defines this as ‘not able to be denied’.

Of course, he was referring to the impact of man’s use of coal on climate change and he is 100 per cent correct. I think I still prefer ‘irrefutable’ and in this context it still means that coal, gas and oil should be used more sparingly and all our actions and proposals for changing the way we live should be checked against this ambition.

The simple rule must be that if the change produces more CO2 then it shouldn’t happen and alternatives that reduce carbon production must be explored.

I do hope that this approach will soon guide the newly-appointed and aptly-named Minister of State for Transport, Justine Greening, as she takes over from Philip Hammond who is now responsible for defending the country.

He has recently stated that he wants the speed limit on the motorways to be raised to 80mph, despite the fact that this would lead to an increase of more than 20 per cent in the amount of fuel used, and so a similar increase in CO2 released to the atmosphere. This excess is not only irrefragable, and irrefutable, but it’s also inevitable.

He defended this decision with the argument that it would help exploited drivers and, anyway, they drove that fast now so it would prevent them from breaking the law.

This attitude demonstrates a level of leadership so weak it will ensure that our behaviour isn’t challenged and climate change will continue unabated. Moreover, despite his assertions, he couldn’t produce evidence that the economy would benefit while ignoring the carbon science that is rock solid.

Every day, members of Cabinet flaunt their lack of environmental commitment. One Cabinet colleague perambulates in a central London park, burdened down with constituents’ correspondence and departmental briefing papers, and, having glanced at them, throws the lot into waste bins.

At least he wasn’t littering, but in consigning good-quality office-grade paper to a landfill site or perhaps a south London energy from waste incinerator, he is ignoring the benefits gained by recycling paper.

He needs to remember that paper is made from wood, and the simple fact is that deforestation, cutting trees down, is responsible for more CO2 than all the world’s transport and domestic heating put together.

I was going to write to him about this, but an e-mail may do less harm.