'The Cities and Biodiversity Outlook' report 2012

The "Cities and Biodiversity Outlook" (CBO) consists of a global assessment of the links between urbanization, biodiversity and ecosystem services. Combining science and policy, scientists from around the world analyze how urbanization and urban growth impacts biodiversity and ecosystems; deliver key messages on the conservation and the sustainable use of natural resources to decision-makers. With the world’s urban area set to triple during 2000 and 2030, growing urbanization will have significant implications on biodiversity if the current trend continues. According to a new assessment made by the United Nations Convention on Biological Diversity, over 60 per cent of the land projected to become urban by 2030 is yet to be built. The assessment has been drawn by the contributions from more than 123 scientists’ worldwide. This presents a major opportunity to greatly improve global sustainability by promoting low-carbon, resource-efficient urban development that can reduce adverse effects on biodiversity and improve quality of life. The report states that urban expansion is occurring fast in areas close to biodiversity ‘hotspots’ and coastal zones. In rapidly urbanizing regions, such as large and mid-size settlements in sub-Saharan Africa, India and China, resources to implement sustainable urban planning are often lacking. The report made a strong argument for greater attention to be paid by urban planners and managers to the nature-based assets within city boundaries. Sustainable urban development that supports valuable ecosystems presents a major opportunity for improving lives and livelihoods, and accelerating the transition to an inclusive green economy. Cities are also increasingly recognized for their role in supporting plant and animal species and diverse ecosystems. For example, over 50 percent of Belgium’s floral species can be found in Brussels, while 65 percent of Poland’s bird species occur in Warsaw. Urban green spaces perform important ecosystem services, such as filtering dust, absorbing carbon dioxide from the air and improving air quality. Data from the United Kingdom shows that a 10 percent increase in tree canopy cover in cities may result in a 3-4°C decrease in ambient temperature, thus reducing energy used in air conditioning. Urban biodiversity also delivers important health benefits. Studies have shown that proximity to trees can reduce the prevalence of childhood asthma and allergies. Sustainable urban planning, which addresses biodiversity issues along with other priorities such as poverty alleviation, employment, and housing, can bring positive effects for health and the environment. Cities need to learn how to better protect and enhance biodiversity, because rich biodiversity can exist in cities and is extremely critical to people’s health and well-being.