Opinion Famed politico-medical journal The Lancet has grabbed big ink by taking the view that providing contraceptives for women in developing nations prevents five times as much CO 2 emission as the same money spent on conventional green measures such as windmill subsidies.

Famous for starting the MMR vaccine scare and for publishing papers suggesting that several per cent of the Iraqi population have died as a result of the 2003 invasion and its aftermath, The Lancet is no stranger to controversy in recent times. Now it seems to be suggesting that western aid policy should focus on getting the world's poor to stop breeding in order to control climate change.

The argument is put forward in an editorial published on paper tomorrow but now available online here (free registration required):

Family planning is five times cheaper than conventional green technologies to combat climate change... each US$7 spent on basic family planning over the next four decades would reduce global carbon dioxide emissions by more than 1 tonne.

This information comes from the Optimum Population Trust, a group of medics and other concerned citizens which has suggested in the past that for a British couple - forget about poor folk in Africa - having a third baby is as evil as having a patio heater or driving a gas-guzzling car. The Trust has told the Reg in the past that Blighty needs urgently to reduce its population by 35 million or so, on the basis of fair shares of world resources. The Trust exhorts the UK public to "sign our stop at two pledge".

The Lancet, however, seems primarily focused on women in developing nations.

Over 200 million women want, but currently lack, access to modern contraceptives. As a result, 76 million unintended pregnancies occur every year. Meeting this unmet need could slow high rates of population growth, thereby reducing demographic pressure on the environment... The UN Copenhagen conference on climate change provides an opportunity to draw attention to the centrality of women. The sexual and reproductive health and rights community should challenge the global architecture of climate change, and its technology focus... Such a strategy would better serve the range of issues pivitol [sic] to improving the health of women worldwide.

Or loosely translated, technology cannot solve climate change - the only way to save the planet is to have fewer people on it. The solution lies in more "centrality" (and so, presumably, less babies) for women.

There might be some trouble ahead for the approach of simply handing out contraception, however. Various religions are strongly against the concept, as are men in some parts of the world. Perhaps, in targeting climate cash at population control, the Copenhagen conference will be required to consider such methods as the Bill Gates funded semi-liquid stealth condom.

Then of course there's the issue of the severe greying of the populace which could be expected during any time of population decrease. The only plan (other than mass immigration, which can only work locally) so far advanced for keeping a developed civilisation running with most of its people too old to do much is the Japanese one, of having lots of robots to do all the graft and care for the burgeoning elderly.

But a massive self-replicating automated robot population and accompanying industries would seem likely to wipe out the carbon gains of having less people - barring some kind of technological solution.

It all seems perhaps a bit trickier than The Lancet and the Optimum Population Trust are making out. ®