Almost a quarter of a billion people moved out of slum conditions in the past decade, driven by rapid economic growth in emerging giants India and China, but the number of people living in them continues to rise, the United Nations housing agency has said.

The number of people living in shantytowns increased by 55 million to 827.6 million as population growth and migration from the countryside outstripped the effect of upward mobility in cities, the UN’s biennial report on cities found.

“The situation has improved over ten years, but alas over the same period, the net increase of the urban poor is 55
million,” Anna Tibaijuka, the executive director of the UN Habitat programme, said in Rio de Janeiro.

The Brazilian city will next week host the World Urban Forum, a five-day UN conference on the state of the world’s cities, where more than half the global population now lives.

Some 227 million people escaped slum conditions from 2000 to 2010, meaning that countries easily surpassed their collective target under the UN Millennium Development target, the report said.

Tibaijuka played down the achievement of beating the Millennium goal of pulling 100 million people out of poverty, calling it “totally inadequate”.

Barring “drastic” action, the number of slum dwellers in the world’s cities is expected to grow by six million a year over the next decade to hit 889 million by 2020, the report said.