HYDERABAD: The global urban population is estimated to be 6.3 billion by 2050, nearly doubling the 3.5 billion urban dwellers worldwide in 2010, posing a challenge in management of biodiversity, says a report by Convention on Biological Diversity here.
The total urban area is expected to triple between 2000 and 2030, while urban population is expected to nearly double, increasing from 2.84 billion to 4.9 billion, during this period.
"More than 60 per cent of the area projected to be urban has yet to be built. Most of this growth is expected to happen in small and medium-sized cities, not in mega cities," said the report.
The report 'cities and biodiversity outlook' was released here Monday during 'cities for life', a city and subnational biodiversity summit, organised in parallel to the ongoing 11th meeting of the Conference of Parties ( COP11) to the Convention on Biodiversity (CBD).
Mayors, governors and other officials from 90 cities, including 50 international cities are attending the two-day summit, to share their experiences and to discuss an action plan for reducing biodiversity loss.
Braulio Dias, executive secretary, CBD, called upon the subnational and local governments to draw an action plan and take steps to implement it for achieving the global biodiversity targets by 2020.
"The urban expansion will heavily draw on natural resources, including water, on a global scale, and will often consume prime agricultural land, with knock-on effects on biodiversity and ecosystem services elsewhere," said the report.
It found that Africa was urbanising faster than any other continent. The overall urban population in 55 nations of Africa is expected to more than double from 300 million in 2000 to 750 million in 2030. The rate of increase in urban land cover is predicted to be the highest in any region in the world: 700 per cent over the period 2000-2030.
Referring to Asia, home to 60 per cent of the world's population, the report said there were large variations in the region with regard to urbanisation levels and urban growth rates.
The urbanisation rate in China will be slower in the next three decades, compared with the last three decades as the urban expansion is moving from the coastal areas to the interior. By 2030, China's urban population is expected to exceed 900 million, an increase of more than 300 million from today.
More than 80 per cent of the population in Latin America lives in cities, and by 2050 it is expected to reach 90 per cent, thus making it the most urbanised of all world regions.
With 10 key messages, the report highlights how urban planners, engineers, architects, policy-makers, politicians, scientists, and citizens alike can take on the challenges of reducing the loss of biodiversity.
The CBD believes that urbanisation is both a challenge and an opportunity to manage ecosystem services globally.
Giving examples of various cities including that of Kolkata and Mumbai, the report explained how rich biodiversity can exist in cities. It made a mention of Sanjay Gandhi National Park of Mumbai.
The report suggested that cities can identify habitats that used to exist locally and restore them.
One of the messages highlighted in the report is that maintaining functioning urban ecosystems can significantly improve human health and well-being, urban ecosystem services and biodiversity can help contribute to climate change mitigation and adaptation and increasing the biodiversity of urban food systems can enhance food and nutrition security.
The report called for integrating ecosystem services in urban policy and planning. It pointed out that cities offer unique opportunities for learning and education about a resilient and sustainable future.
"Cities have large potential to generate innovations and governance tools and therefore can - and must- take the lead in sustainable development," says the report.