The United Nations (UN) has released a report showing that greening city urban infrastructure can sustain economic growth while using fewer natural resources.

The report ‘City-Level Decoup-ling: Urban Resource Flows and the Governance of Infrastructure Transitions’ included thirty cases showing the benefits of having gone green. The report was compiled during 2011 by the International Resource Panel (IRP), which is hosted by the UN Environment Programme (UNEP).

The findings show that investing in sustainable infrastructures and resource-efficient technologies in cities offers an opportunity to deliver economic growth, with lower rates of environmental degradation, poverty reduction, lower greenhouse-gas emissions and improved wellbeing.

About three-quarters of the world’s natural resources are currently consumed in cities and the proportion of the global population living in urban areas is set to rise to 70% by 2050. Simultaneously, cities offer lower per capita resource use and emissions than their surrounding areas.

The UN report requires the decoupling of city-based eco- nomic growth rates from the unsustainable consumption of finite natural resources, which has characterised most urban development to date.

As the price of depleting natural resources continues to rise, promoting sustainable urban infrastructures can benefit the environment and shield cities from potential economic and social instability on an increasingly resource-constrained planet.
“So far, the trend towards urbanisation has been accompanied by increased pressure on the environment and growing numbers of the urban poor,” says UN under-secretary-general and UNEP executive director Achim Steiner.

He adds that there are unique opportunities for cities to lead the greening of the global economy by increasing resource productivity and innovation, while achieving major financial savings and dealing with environmental challenges.

The report shows that greater effort is needed to support new and improved infrastructure for water, energy, transport, waste and other sectors located in and around cities to wean the world off unsustainable consumption patterns and avoid serious economic and environmental implications for future generations.
Sixty per cent of the built environment required to meet the needs of the world’s urban population by 2050 still needs to be constructed and the cost of meeting the urban infrastructure requirements of the world’s cities between 2000 and 2030 is estimated at $40-trillion, through the building of new infrastructure in developing countries or retrofitting existing facilities in developed nations.
The IRP report indicates that these funds should be channelled into sustainable infrastructure that reduces carbon emissions, improves resource productivity and avoids the resource-intensive urban planning of the past.

The report recommends that government investments should support the role of cities in national sustainable development strategies and infrastructures that stimulate low-carbon, resource-efficient and equitable urban development.

With regard to the private sector, the report recommends that it should invest and share expertise to take small-scale sustainable infrastructure projects to a citywide scale.