Half the world's people now live in towns and cities. In little more than a generation, two-thirds of the global population will be urban. As the proportion of humanity living in the urban environment grows, so too does the need to strengthen the urban focus of our efforts to reduce global poverty and promote sustainable development.
From necessity springs opportunity. Better planned and better functioning cities can help guide us to the future we want: cities where everyone has adequate shelter, water, sanitation, health and other basic services; cities with good education and job prospects; cities with energy-efficient buildings and public transport systems; cities where all feel they belong.
Good practices of managing urban development exist in all regions - and we can learn from the examples they provide. But we are a long way from turning the ideal of sustainable, inclusive cities into reality. Urban areas are responsible for most of our waste and pollution. Many are particularly vulnerable to disasters, including the growing risks associated with climate change. And, while we have achieved the Millennium Development Goal target of significantly improving the lives of at least 100 million slum dwellers 10 years in advance of the 2020 deadline, absolute numbers continue to grow. Nearly a quarter of urban residents - more than 850 million people - live in slums or informal settlements.
Ninety per cent of the world's urban expansion is in the developing world.
A sizeable proportion of the inhabitants are young people - by 2030, as many as 60 per cent of all urban dwellers will be under the age of 18. It is essential that these young people have access to decent employment and quality education.
This year's Rio+20 conference on sustainable development recognized the importance of cities to economically, socially and environmentally sustainable societies. It stressed the importance of global partnerships in implementing the Habitat Agenda and highlighted the key role of municipal governments in setting a vision for sustainable cities, from planning new urban areas to revitalizing older cities and neighbourhoods. On this World Habitat Day, let us urgently commit to work together for integrated, holistic management of the urban environment for the benefit of people and the planet.