IN your cryptic crossword on Monday (January 20), the answer to 14 across was "nuclear reaction". Thus my efforts to distract myself from the horrors of today’s world were interrupted as my mind jumped to the Doomsday Clock and its setting date, 23.01.20.

For those who need reminding, in 2019 a group of eminent scientists set the clock at two minutes to midnight because of the dual threats from nuclear weapons and climate change.

There are world leaders who are prepared to use nuclear weapons on the battlefield (that is, distant countries well away from their own population), believe planting “a trillion trees” will allow endless excess in use of oil, precious minerals and destruction of the natural environment ("Trump blasts climate change ‘prophets of doom’ at Davos", The Herald, January 22) and are supported by, presumably, people who do not or prefer not to believe the views of the vast majority of scientists.

Decades have passed since Petra Kelly founded the Green Movement, Jacques Cousteau warned about damage to the oceans, Greenpeace and the Rainbow Warrior took to the seas, Friends of the Earth started campaigning and many brave individuals defended forests, trees and rivers.

Greta Thunberg and David Attenborough are now carrying the baton. A teenager and a man in his nineties should not have to do this. We elect leaders, they declare a climate emergency and either do very little or are hamstrung by unsustainable economic patterns. A new system of values is needed.

No arms dealing, no nuclear weapons (support the UN Treaty for the Prohibition of Nuclear Weapons), no excessive salaries salted away in tax havens, shared knowledge to help heavy polluters like India and China, help for the people fleeing from war, famine, fire and floods, care for our own deprived families, The list is endless and there are those with more knowledge than mine whose ingenuity can and must save our this planet.

Sandra Phelps, Glasgow G20.

THERE is a lot of misinformation about the proposed “Red John” pumped hydro scheme in your article ("Public inquiry into £625 million green energy plan at Loch Ness", The Herald, January 20).

In its description of the scheme the article uses the words “huge” and “massive”, but the vital statistic of gigawatt hours stored is omitted. And Brian Wilson states that pumped hydro “is the obvious answer in Scotland” to the uncontrollability of wind and solar output.

The reality, as Sir David MacKay, former Chief Scientific Advisor to the Department of Energy and Climate Change calculated would be that Britain would need thousands of pumped hydro schemes to stand a chance of smoothing out wind and solar energy.

Mark Wilson of ILI, the company behind the scheme, makes a similar disingenuous statement. He says wind and solar “can provide constant power when backed up by storage”. The amount of storage that Britain could feasibly deploy in the foreseeable future could be totally discharged in minutes if our future wind and solar capacity were to be dependent on it for constant power.

Energy doesn't like to be stored; it likes to be distributed throughout the universe.

Geoff More, Alness.

THE proposed “Red John” pumped storage hydro power at Loch Ness has been refused planning permission. You quoted Brian Wilson describing the need for back-up because of the intermittency of renewable generation. But nearly all forms of generation show a mismatch between generation and demand, as can easily be seen on Grid Watch (gridwatchtemplar.co.uk).

It would be equally correct to say that back-up is needed because of the inflexibility of nuclear and coal-fired power – described by Professor Win Rampen (Professor of Energy Storage at University of Edinburgh) as "intransigence". Either way we need to expand energy storage. Whatever happened to the proposal to double the size of the storage facility under Ben Cruachan?

Neill Simpson, East Dunbartonshire.

I RECEIVE regular updates from The TaxPayers' Alliance of waste in the public sector and how it is not only highlighting it but also forcing the guilty to change their ways. I was astonished at its most recent disclosure under the heading Air Passenger Duty (APD) where it was confirmed that APD is not and never has been an environmental tax although the Greens would like it to be and trebled to "save the planet". But the real disclosure which gave me pleasure, and no doubt the climate brigade nightmares, was that global aviation only produces around two per cent of all human CO2 emissions. The climate change apostles should look at the world population, which is 7.7 billion now and will be 10 billion by 2050.

Clark Cross, Linlithgow.

Read more: Trump hits out at environmental 'prophets of doom'