HUGH Boyd’s view that our pensions “problem” can be solved by mass immigration (Letters, November 3) is at least 50 years out of date, belonging as it does to the era of assembly lines and manual labour. Now that factories are increasingly staffed by robots it is quality, not quantity, of workers in the national workforce that matters – and mechanisation and computerisation are really just starting. One recent projection is that half the jobs currently being done by humans will have gone in a generation. Just as population growth was encouraged in the past to service the technologies that industry then required, so now populations should be encouraged to fall to fit the technologies of the future.

Ecological needs align with economic on this issue: the ecologically sustainable population of the UK is around 29 million, but the population is heading for 70 million. Already 40 per cent of our food is imported, so every extra person living in the UK means another mouth to feed with food bought on world markets (and that is running at about one million extra mouths every four years at present). Every extra person also means more housing, which means more gravel pits for construction materials; more roads; more energy imports; more rivers abstracted or valleys flooded for water supplies; less green space; less land to produce our own food (the highest grades of arable land used to be protected from development as a matter of national security, but that was abandoned in the Thatcher years) and general environmental degradation. The fact is that increasing population is no longer an economic credit but is an ecological debit and our politics and policies must reflect this.

One driver for imperial expansion in the past was to ensure food supplies for the workforce of an industrial Britain that was swollen far beyond the capacity of its own agriculture to support. That era has gone as has the industrial wealth that also helped ensured our food supply: “Britain’s bread hangs by Lancashire’s thread” was a saying of the past when we had serious politics that included fundamental issues like food security (anyone ever heard a modern politician of any party talk about food security?).

Reducing our population to that which we can, more or less, sustain ourselves is not just a matter of national security but of vital personal concern to anyone with grandchildren. That means having more old people than young for a good many generations and not allowing the “space” so created to be filled up by immigration. Whatever “problems” an ageing population is supposed to cause for pensions and so on they are merely social and economic problems, created by humans and therefore solvable by humans. The environmental problems that overpopulation is driving this country and the planet into may well not have any human solutions.

RN Campbell,

Tigh-ur, by Pitlochry, Perthshire.

HUGH Boyd is very optimistic that immigrants can "reinvigorate our workforce" and "rebalance the age distribution" in Britain. He is off-centre in making a direct comparison with Germany taking in refugees after the Second World War. The mix is very different, so that is not a template for success.

Mr Boyd seems to assume that all potential immigrants would raise themselves to what they had in their countries of origin, but not a few seem unqualified and disruptive, or at least that's what the TV images indicate. “Anything is better than what we have left behind” has been a comment, which does not inspire confidence in the development of their homelands.

There are serious cultural and religious integration issues to be taken into account. German reception centres reportedly are being overwhelmed, and there is a backlash particularly against Muslims. That could happen in the UK, which remains fundamentally Christian, and already has shown stress in several towns and cities which now have ethnically divided localities. We should act as a haven for the oppressed, but if the numbers are so large and the incomers so mixed in terms of economic versus asylum seekers, there has to be an urgent agreement by Westminster and indeed our parliament on the least disruptive solution.

German Chancellor Angela Merkel erred in encouraging the huge flow into Europe, and is now reportedly effectively paying Turkey to hold back more migrants in its camps - already numbering two million. The UK should at least offer funding too for the faster development of the poorer countries, this may be the only long-term way to help.

Joe Darby,

Glenburn, St Martins Mill, Cullicudden, Dingwall.