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The earthquake struck Haiti over two weeks ago now, but remarkable stories of people being pulled alive from the rubble have emerged throughout. Uplifting stories that highlight the huge efforts being made by Haitians themselves, as well as specialist aid workers who have flown in from around the world, to rescue trapped strangers.

Humanity's virtues have also being demonstrated by the hundreds of millions of dollars of aid that has being pledged, not just by governments, but by private individuals. In this week's One Planet we consider our growing willingness to help one another by digging into our pockets.

During the past decade, private donations from the world's richest nations have risen at over twice the rate of growth seen in official government aid.

We speak to fund raiser Renu Mehta about why the rich - the super-rich - give away large sums of money, and we hear from Africa, as Zambians tell us why they feel compelled to send money to Haiti.

Also in the show we take ecologist Stewart Brand out onto the top of One Planet HQ to look down on London and explain his love of cities. Plus we hear some scary bedtime stories. As ever, tune in and let us know what you think. Email Mike and the team on oneplanet@bbc.com. Or join in the conversation at our Facebook page - the link's below. See you there.