Ecologists and environmentalists from across the globe are heading to Oxford to take part in debates and events to promote World Environment Week.

The week begins today and among those heading for the city are former South African president Nelson Mandella's daughter, Dr Maki Mandella. She will be taking part in a rare public debate at the Oxford Union, St Michael Street, at 8pm on June 13.

She will be speaking against America's refusal to sign up to the international Kyoto accord to limit pollution.

Today (Tuesday), scientists from Africa and the Wytham Woods Discovery project in Wytham, near Oxford, will be at Borders bookshop in Magdalen Street to give illustrated talks. Other events include a roadshow at the East Oxford Community Centre on Saturday, when the campaign group Rising Tide Combating Climate Chaos with Local Action, will provide advice on how people can help stop climate change.

George Marshall, the group's Oxford representative, said: "We want to encourage people to take action in their local community.

"We aim to encourage people to act locally to create local change, but also to pressure govern- ments to take action to reduce energy consump- tion, reduce car use - basically, change the way we live."

A benefit concert takes place on Saturday at the community centre from 9pm by eco-conscious folk band Seize the Day.