If anyone knows a thing or two about how powerful it can be to bring people together, it's Bill Gates. And now, he's got a big ask: he wants us each to commit to becoming a Global Citizen and help to end extreme poverty and improve the rights of women around the world by 2030.

Gates was at Facebook HQ in London yesterday for an event hosted by by BBC Radio 1 DJ Greg James, answering questions from a live audience (and also via the internet - but of course) about the biggest challenges of our generation, such as poverty, health and educational opportunities, gender equality and climate change.  

When Lorraine Candy met Melinda Gates

We can all make a difference, he insisted, urging everyone to sign up to GlobalCitizen.org - an online campaigning platform for people to share, communicate and take action on issues affecting the world's poorest - and get involved.

'I've seen such remarkable generosity when disaster strikes around the world. People want to help. They donate their time and their money to help other people in need,' he said. 'But the issues affecting people in the developing world – access to basic health care, clean water, nutritious food and proper sanitation – don't make headlines every day.

'That's where Global Citizen comes in.

'We want to tap into that generous spirit by sharing both information about these issues and ways people can help. We've made great progress but there is much further we can go when we harness the generosity and commitment of the millions of people around the world.'

Empowering women will be a key part of the fight, he added: 'If you educate women, they will educate their daughters and so on. It’s catalytic to the entire society.'

Help make a change today; find out more at globalcitizen.org now.