KEY POINTS:
There comes a time when campaigners lose potential support from fence-sitters, doubters or sceptics because they go too far. We've seen it with people like John Minto and Father Gerry Burns. Well-intentioned folk who, in their support for the Palestinians, muddled Hamas into the mix and veered off into other actions.
In Britain this week, Sir Jonathan Porritt labelled couples who bear more than two children "irresponsible" because they contribute to global warming and the destruction of planet earth.
Sir Jonathan has clout. He is chairman of Tony Blair's Sustainable Development Commission and chief adviser to Prince Charles and the Government on green matters.
Eton and Oxford-educated, Sir Jonathan, who inherits his baronetcy from his dad, Sir Arthur Porritt, New Zealand's 11th Governor-General, is also a patron of the powerful lobby group Optimum Population Trust.
This group's main slogan is "Stop At Two" - coincidentally or not, the number of children at which Jonno and his Lady Wife have stopped. Only a cynic would presume this distinctly privileged couple had eschewed continuing their own bloodlines and adopted their children from a freezing cold orphanage in Ukraine or an over-crowded institution in Thailand.
Last week Sir Jonathan said he was "unapologetic about asking people to connect up their own responsibility for their total environmental footprint and how they decide to procreate".
According to this British toff, we should seriously consider contraception and abortion as weapons against climate change. After all, he reckons, every Pommie child in its lifetime will destroy more than two acres of "old-growth oak woodland".
I suppose in New Zealand the equivalent would be trashing several hectares of native bush.
I look forward to the reaction from our Family First lobby on hearing New Zealand women, pregnant with a third child, can rush to a certified GP seeking an abortion on the grounds that a nice patch of West Coast beech forest is more important than human life.
And why stop at humans? If man is destroying the planet, then surely domesticated or agricultural animals are also irresponsible culprits? All those dairy herds supplying milk, butter, cheese, by-products - income and a better standard of living for millions - should be dog tucker.
Dog tucker? That presupposes dogs are allowed to survive. It won't just be Kelburn and Remuera's bichon frises being mass-euthanased, but also huntaways, heading bitches, police and guide dogs will go off to the happy hunting ground in the sky.
No more racehorses generating employment for jockeys, strappers, stablehands, grooms, trainers and TAB staff. Chooks, cats, sheep, ducks, anything not feral or native - off with their heads.
To be fair, the trust's website declares its members are absolutely opposed to any coercion regarding population control. But one can almost sense the "yet" at the end of that statement. Limit your families voluntarily, or else.
Sir Jonathan is just one patron among a who's who of aristocracy, luvvies and academics.
A fellow patron is Susan Hampshire OBE, who was so lovely in the TV series The Forsyte Saga that many men of my generation would have traded their inheritance to practise procreating with her.
Joking aside, we should be uneasy. Sir Jonathan advises the Government to consider "shifting money from curing illness" if necessary. As Toby Young wrote in the Spectator, "the plague that is modern medicine can be eradicated if you put your mind to it. Thanks to [Pol] Pot's enlightened attitude to healthcare - he outlawed all medical drugs - over a million Cambodians died during his reign."
On the other hand, a comment on the trust's blog site supporting Sir Jonathan's outrageous advice recommends "fewer but better-educated people" and "it's better to raise little emperors". If being better educated (at Oxford and Eton) results in people choosing to let children die from curable diseases so that hectares of oaks can survive, then give me ignorance any day.
Meanwhile, I can't wait until a loopy greenie here has the cojones to suggest some of our most virile high-profile sires of litters - Sir Robert Jones, Bill English, Jim Bolger, Bob Harvey, Tom Scott and, good gracious, the QC and I share nine children - might indulge in some upper class self-flagellation for our irresponsible breeding of environment trashers.
