Scotsman: JONATHON Porritt, the leading environmentalist, has said couples who have large families are “irresponsible” and that we should all limit ourselves to two children in order to help save the planet. But his argument, in a newspaper article, brought an angry reaction yesterday. It upset many parents, who feared it risked putting the UK on a par with communist China, where couples are limited to just one child each. Susan Christie, of Cromarty, on the Black Isle, who has …