David Coleman on population and the environment – live chat

In little more than two months' time, the UN predicts , a boy or girl will be born that takes the human population to 7bn for the first time. This month the journalist and author Fred Pearce discussed his views on why he thinks population is not a "timebomb" and why consumption is the real ecological problem. This Wednesday, we're joined for a live webchat on population and environment by one of the country's leading demographers, Prof David Coleman of Oxford University . He'll be here from 1-2pm to answers your questions, from the numbers to the pressing issues. Interested in what parts of the world are driving the population growth? Want to know whether he thinks the planet's resources and ecosystems can support a human population of 7 billion? Whatever you want to ask about population and the environment, this is your chance. Just post your questions below - Coleman will be online at 1pm on Wednesday to answer .