ONE of the points which seems to have been made repeatedly in the public debate about electric cars is that people are unlikely to want to use a car which has a range of less than 200 miles, and to have to wait for an hour or two to regain some useful charge to the car. This is an opportunity for the European Union to impose a range of standard mechanical designs for automotive batteries to enable easy re-placement. Existing service stations should sell replacement batteries (in a range of two or three ca-pacities). This would be similar to the way which people buy replacement gas cylinders. There is a pos-sible objection that batteries will inevitably degrade throughout their life, but this could easily be elec-tronically monitored so that the payment is made for the exact amount of energy used.

It would be the service station's responsibility to replace battery packs as they reach the end of their useful life, and need to be re-cycled. These two issues of mechanical standardisation and battery dis-posal need to be addressed before there will be a significant popular take-up of the technology apart from those who have a moral conscience to do this.

Following on from this, I suggest lowering peak loads on the national grid by providing a collection ser-vice from service stations to local renewable energy providers (for example, wind, hydro, tidal electric-ity generators). The overall battery supply system should be designed to have a time constant of the order of 10 days, then there would be time to make efficient battery collections, and give the time to wait for a large output from renewable energy sources.

Assuming that there are beneficial energy and pollution savings with electric vehicles, it is essential that there should be more direct government involvement to defining standards and so on, as well as financial incentives.

These are interesting times which we are living in.

Archie Shaw Stewart, Doune.

THERE'S no doubting Rose Harvie's sincerity (Letters, November 15) and her fears for the planet's fu-ture with climate catastrophe, but what more does she want our politicos, of all parties, to do in prac-tice?

They all plan to spend huge sums on decarbonisation in the hope that will prevent dangerous climate changes. A vast outlay is pledged, some £3 trillion, although the national UK debt is already £2tn, cost-ing £1 billion a week in interest.

Ms Harvie is convinced that Earth will "go down the tube" without stronger action. It is true that the UK's output of CO2 is negligible at one third of one per cent of the global total. The great bulk of greenhouse gases come from non-complying nations who will not listen to any pleas to cut carbon.

How can we be sure that Earth faces catastrophe or that decarbonisation could help avert it? Despite all the worrisome publicity, scientific controversy in fact now reigns.

Maybe we could make the best of the controversy by concentrating resources on health and welfare, education, infrastructure and our military defences against manmade aggression?

(Dr) Charles Wardrop, Perth.