It all sounds very Orwellian and nightmarish at first. Governmental controls on how many children a family can have; the ease with which global efforts to slow population growth might unfairly be focused on developing nations; the loss of one of our most basic human liberties, the freedom to procreate. But more and more, respected experts are making their voices heard on the subject -- people like Sir David Attenborough and Dame Jane Goodall, who have joined a British awareness organization called the Optimum Population Trust, which pushes for the voluntary reduction of the British population by at least .25% a year.

Until recently, the Trust says, government policy-makers and environmentalists appear to have been purposely silent on the topic of population growth, engaging in a kind of lie of omission, tacitly implying that the population can continue to grow unchecked forever with no ill effects. (Another Trust initiative is the "Stop at Two" program, the title of which is pretty self-explanatory.) For instance, between now and 2051, the UK population is expected to increase from 61 million to 77 million, but scientists have determined the long-term environmentally sustainable population of the UK to be around 30 million.

In terms of the Earth as a whole, no one's quite sure what its "ideal population" is, but most believe it's less than we have now. There are also per capita consumption issues to address -- the fact that the USA accounts for only 5% of the world's population but uses 25% of its resources, for instance. I'd like to think that we're working on it -- or beginning to, at least -- but without some checks on population growth, experts agree, per capita consumption reduction alone will not solve our problems.

Obviously this is a hotly contentious topic, but at the risk of starting a flame war, I'd love to hear what our readers think about it. How many of you think the "Stop at Two" program has the right idea?