However, urban areas, although better served than rural areas, are struggling to keep up with urban population growth.

UNESCO: World Water Assessment Programme (WWAP)

The objective of World Water Day 2011 is to focus international attention on the impact of rapid urban population growth, industrialization and uncertainties caused by climate change, conflicts and natural disasters on urban water systems.

UNESCO: World Water Assessment Programme (WWAP)

During the consultations governance challenges in arid and semi-arid areas were discussed and how institutions can be better equipped to deal with risks and uncertainties, emerging out of climate change, population growth, urban-rural tensions and groundwater pollution.

UNESCO: OFFICE IN AMMAN

And China is able to maintain its export-led economic growth, generating jobs for its growing urban population, while continuing to attract foreign investment.

BBC: Analysis

Metropolitan Portland's 1.5 million population is already putting pressure on housing needs within the urban growth boundary, and another 700, 000 people are expected to move to the area during the next 20 years.

CNN: Polluted rivers stain Portland's image