WITH regard to Dr Charles Wardrop's concern that a) climate change may not be caused by human activity, and b) the costs of cutting man-made carbon emissions may be too high (Letters, January 24), I trust Dr Wardrop does not have grandchildren who will look back and say "Grandpa knew what to do but he didn't do it".

It is now acknowledged by most scientists who have researched the causes and possible solutions to climate change, that the economic costs of mitigation – preventative measures – are much, much, smaller than the likely costs of adaptation to the effects of climate change. My motto, for the sake of my grandchildren is "better safe than sorry".

Rose Harvie, Dumbarton.

IN focusing on the possible costs of carbon reduction actions Charles Wardrop, conveniently forgets another economic measure, the opportunity costs of not reducing these emissions.

The distress and financial costs to Australian friends through the intense bush fires give just one cameo of the total likely to be incurred by the whole world if Donald Trump and Dr Wardrop succeed in persuading us not to bother cutting emissions. There is a technique in economics called discounting, which tries to compare costs incurred today with benefits which only accrue years later. This technique reduces the value of future benefits by a proportion for each year that elapses before they are achieved. The proportion is called the discount rate, and the higher it is, the lower a value is placed on benefits accruing in the future compared to their current cost. The value of the discount rate is related to current financial interest rates, so given the negligible return on investments at the moment with a bank rate below half of one percent, one would now expect the discount rate to be similarly low, and future benefits to be highly valued. Dr Wardrop and his ilk clearly do not recognise this, and would set a mental discount rate close to 100 per cent, totally devaluing future benefits.

Of course, these same people claim that the costs of climate change will be minimal, if indeed there is any change. The fact that the scientific evidence contradicts this overwhelmingly matters not a jot if it potentially restricts their selfish activities.

The last straw for any reasonable humanitarian is his suggestion that, because Scotland's emissions are only a small proportion of the global total, nothing need be done. So at what percentage of the total does it become morally necessary to take action? In Dr Wardrop and Mr Trump's world, there is no level at which emissions cannot be considered to be trivial. Future generations are likely to judge matters in a very different way.

Dr RM Morris, Ellon.

IN an era of gloomy prophecies, the absurd Doomsday Clock claims to count down the seconds to a looming global apocalypse. But even the most scientifically challenged must suspect it is conflating disparate threats with varying degrees of urgency: nuclear war, climate change, and emerging technologies.

The stated motivation of those involved in this absurdity is to apply pressure to governments by calling on citizens “to express themselves in all the ways available to them.” But we already have the endless rants of the Swedish prophetess Greta Thunberg and most of us could do with just the tiniest break.

Rev Dr John Cameron, St Andrews.

THE fiscal lunacy of spending £14 billion on foreign aid is worth exposing. First, we don't actually have £14 billion to give away. As we run a deficit economy, that money has to be borrowed – at interest of course.

Our cumulative annual deficits to date – the National Debt – amount to £2 trillion. That is two thousand billion pounds. The annual interest on that sum is around £1bn a week: £52bn a year.

So our £14bn of largesse to countries who either don't need it, or who don't like us, would pay the interest on our National Debt for fourteen weeks.

Sooner or later, if we carry on living beyond our means, we are likely to be in the clutches of the IMF. One more Labour government would do it, but the money wasted on becoming carbon neutral will certainly do it if we don't wake up to the fact that climate change is a plot to collapse the western financial system.

And even if we were to continue with this daft scheme, we need only to look at the plight of Australia to find a deserving recipient for £14bn.

Malcolm Parkin, Kinross.