UN report warns of effects of urban expansion on biodiversity

Urban areas set to triple by 2030; population to touch 4.9 billion

A new assessment by the United Nations Convention on Biological Diversity (CBD) warns that if the current trend of global urbanisation continues, it will have significant implications for biodiversity and ecosystems along with knock-on effects on human health and development.

The assessment report states that urban expansion is occurring fast in areas close to biodiversity hot spots and coastal zones. In rapidly urbanising regions, such as large and mid-size settlements in sub-Saharan Africa, India and China, resources to implement sustainable urban planning are often lacking.

Key highlights of the report

ASIA

• The region will be home to almost half the world’s increase in urban land over the next 20 years. The most extensive changes will occur in India and China

•India’s growing urban clusters (such as the Mumbai-Delhi industrial corridor) are likely to transform entire regions with significant impacts on habitat and biodiversity

• Loss of agricultural land to urbanisation, combined with insufficient planning for food supply lines, places a severe constraint on future food security for India’s growing population

• Lifestyle changes in India due to urbanisation may decrease pressure on forests due to less use of fuelwood and charcoal

• In China, urban areas are increasingly encroaching on protected areas

AFRICA

• Africa is urbanising faster than any other continent, and most population growth will occur in cities of less than 1 million people. These cities often have weak governance structures, high levels of poverty and low scientific capacity for managing biodiversity

• Low levels of formal employment in cities places high dependency on the provision of ecosystem services (e.g. water and food production) from areas either within or close to city limits.

LATIN AMERICA AND THE CARIBBEAN

• The number of cities in the region has grown six-fold in the past 50 years

• Urban sprawl caused by housing for low-income residents often occurs in important areas for biodiversity and ecosystem services, such as wetland or floodplains. These are mistakenly considered to be of marginal value by planners

EUROPE AND NORTH AMERICA

• In Europe, the current urbanisation level is 70-80 per cent, and urban growth in recent decades has mostly been in the form of land expansion rather than population growth

• Many European and North American cities have exhibited trends of shrinking and/or shifting patterns of population in central parts of the cities, coupled with sprawl in outer suburbs and exurban areas

Window of opportunity

Urban lungs

Convention On Biological Diversity (CBD)