It's been a very exciting and emotional two weeks cheering on the Olympians, but the highlight for me was Cameron leaving a legacy of London 2012 beyond even our exceptional haul of medals by hosting a global hunger event bringing together sportspeople and senior politicians from Brazil, Kenya, Bangladesh and India. When he could have been celebrating his twin gold medals elsewhere, instead the Somalia-born Mo Farah was running up a temporary race track outside Number 10 Downing Street to angle his spotlight towards global hunger.

How would I rate Rio? 6 out of 10 - maybe even seven if, crucially, what they declared now leads to real action, rather than self satisfaction. And that's now up to our politicians.

When flash floods hit Wales earlier this month necessitating the evacuation of more than 1,000 people, my thoughts immediately returned to the people I met last month in Cagayan de Oro in the Philippines who had also been affected by flooding. I also reflected on the floods that hit my own constituency, Workington in 2009 and how it shook our community.

If Rio+20 is to steer us on a path of cooperation rather than conflict and a sustainable future for our children it is vital that David Cameron, Nick Clegg and other world leaders are not afraid to dream.

As Rio hosts the Earth Summit's opening today, War on Want is joining forces with more than 100 civil society organisations to launch a campaign for world leaders to put the needs of people and the planet before the profits of big business.