Nairobi, 3 October 2011 - The central role played by cities in tackling climate change and in the transition to a low-carbon Green Economy is at the forefront of World Habitat Day, hosted this year in Aguascalientes, Mexico, under the theme "Cities and Climate Change".
Cities and towns are major sources of greenhouse gas emissions through industry, transport, buildings and energy. Moreover, with the majority of the growing global population now living in urban areas, impacts of climate change -such as rises in sea levels and shortages in water supplies -will directly affect city dwellers in greater numbers in the coming years.
But cities are also increasingly recognised as a source of innovative solutions to climate change and sustainable development. As countries prepare for the United Nations Sustainable Development Conference (Rio+20) in Brazil in June 2012, there are real opportunities for cities to lead the greening of the global economy, where economic development can reduce environmental risks and improve human well-being.
Take the city of Delhi, for example, which hosted UNEP's World Environment Day on 5 June 2011. Delhi's metro system has become the world's first railway network to earn carbon credits from the United Nations for helping cut greenhouse gas emissions. The transport system has helped reduce pollution levels in the city by 630,000 tonnes a year and has improved the quality of life for its 1.8 million daily users. The carbon credits are worth US$9.5m annually for seven years.
Today, our homes and offices contribute to around one third of global greenhouse gas emissions. The development of greener buildings to house the world's fast-growing urban population is therefore essential to tackling climate change.
UNEP's Green Economy Report, which contains chapters on both cities and buildings, shows that failure to transform the building sector and to rely on more costly emission reductions from other sectors, would increase the economic cost of combating climate change by at least US$500 billion per year globally between 2010 and 2050.
Additionally, the green building sector has the potential to be an important economic driver. UNEP's Green Economy Report shows that energy efficiency investments in homes and offices could generate some 3.5 million green jobs in Europe and the United States alone. With the demand for construction in developing countries, that number will be much higher.
UNEP is proud to share with UN-Habitat one of the greenest buildings in Sub-Saharan Africa: the New Office Facility at the UN compound in Nairobi, Kenya. It is hoped the energy-neutral building will now provide a model for green buildings in developing countries.
Green buildings are a prime example of the concept of 'decoupling', explored by UNEP in its report released in May 2011. The basic premise is that we can reduce the amount of resources used to fuel economic growth, thus 'decoupling' economic development from environmental deterioration. The technology and innovation found in cities - whether in green buildings, public transport or renewable energy - can spur the transition to a Green Economy and make decoupling a reality.
Greener cities are also healthier cities, with lower air pollution meaning less respiratory diseases. Green spaces in urban environments, such as parks or trees, also play a key role in improving community cohesion and quality of life.
The Rio+20 conference in June will be a landmark opportunity for renewing political commitment to sustainable development and to a low-carbon, resource-efficient Green Economy, unlocking the potential of cities to tackle today's climate challenges and help achieve economic, environmental and social benefits for the world's urban dwellers.