David and Victoria Beckham have been given a bit of a kicking in the press as they welcomed their new daughter, Harper Seven, last week.  A large number of campaigners have stated that the birth of their fourth child make the couple bad role models and environmentally irresponsible.

The world's population is due to hit seven billion at some point in the next few days,  50 years ago there were 3 billion. It is the one part of environmentalism is that people are scared to touch. No one should tell you how many kids you should have! But, it is obvious, as a planet, we need to talk about this. China and India, the largest consumers of fossil fuels, have huge populations, with large swathes living in poverty. How can this continue? We in the UK are rapidly growing. When I did GCSE geography, the UK population was 52 million, it is now pushing 70 million. England is one of the most densely populated countries in the world and the fastest-growing in population terms in Europe. In 15 years we'll have an extra 10 million people here.

Sir David Attenborough (the greatest man in the world after my dad IMO) has called discussing this boom the "absurd taboo" in discussing family size in the UK and on a global level.

By 2050, most environmentalists expect the world population to hit 9 billion. There is not enough resources to fuel this growth. People will be plunged deeper into poverty, and food and resources will continue to diminish.

A Green Party MP (my mum has always voted Green, the hippy!) said : "We live as if we have three planets instead of just one. It is interesting that public figures, environmental groups and NGOs in general have tended to steer away from population to the extent that it's become a taboo issue. The horrific consequences of China's one-child policy and of other draconian efforts to regulate procreation have, for many, rendered discussion of the subject completely unpalatable. Yet as long as an issue remains a taboo subject where no one talks about it, then there's very little chance of finding the solutions we need."

It sounds harsh as a society to impose rules like giving child benefits and tax credits only for the first two children, but how else do you deter people from having huge families that are a drain on the tax system, and society as a whole? It sounds horribly Tory to work in that way, and this is where the taboo element comes in. Who are we to tell anyone how to live their life, and how many kids to have? I feel sometimes people think large families are just a way of getting more money from the state, but some people have religious reasons, others obviously have a massive whole in their hearts which no matter of children will fill.

The population debate has often been overshadowed by the inhumane experiment by China, with its notorious one-child policy, and with sensitivity about being seen to criticise birthrates in underdeveloped countries. But it is the populations of the developed world who use the vast majority of the world's resources.

At its heart, this is a debate about poverty and inequality, as well as about sustainability . Through strong policies to reduce the gulf between rich and poor should underpin every effort to address it.

As a richer country, we face different challenges when it comes to population than those in the developing world, where high birth rates are linked to poverty and inequality. But the whole planet has these issues, and needs for them to be addressed if we are to move to a more sustainable global community.

- Anand