Over the last two decades, demographic and economic changes have propelled cities to become the principal habitat of humankind. Cities are not only where rapid improvements in socio-economic and environmental conditions are possible. But it is, indeed, where such change is most needed. The cities of the world’s emerging economies are increasingly drivers of global prosperity while the planet’s resources are fast depleting. Therefore, it’s more critical than ever that Member States and United Nations agencies commit themselves to sustainable urbanization for development.
We must urgently find ways to achieve economic and socially equitable growth without further cost to the environment. Part of the solution lies in how cities are planned, governed, and provide services to their citizens. When poorly managed, urbanization can be detrimental to sustainable development. However, with vision and commitment, sustainable urbanization is one of the solutions to our ever-growing global population. Efforts to create jobs, reduce our ecological footprint, and improve our quality of life are most effective when pursued holistically. By prioritizing sustainable urbanization within a broader development framework. Many critical development challenges can be addressed in tandems. For instance, energy, water consumption and production, biodiversity, disaster preparedness, and climate change adaptation. It is vitally important that this emerging opportunity be recognized and endorsed at Rio+20.
THE URBAN DIMENSION OF sustainable CLIMATE CHANGE
The effects of urbanization and climate change are converging in dangerous ways. The world’s population is already more than 50% urban and may rise to two-thirds over a generation. Cities and towns already bear the brunt of natural disasters such as flooding and tropical storms. Many of the world’s largest cities and towns are located along coastlines, rivers, and floodplains which are most vulnerable when natural disasters strike.
Forecasts based on the best available scientific evidence indicate that in the coming decades, climate change may render hundreds of millions of urban residents increasingly vulnerable to floods, landslides, extreme weather, and other natural disasters. Increasingly, it has huge impacts on the poorest. Yet they have the least capacity to mitigate against these impacts and protect themselves. For example, research in UN-Habitat’s* most recent State of African Cities Report suggests that as many as 200 million Africanshave a display of the effects of climate change by the year 2050, putting a huge strain on the capacity and resources of cities.
Asia is also far from immune to the effects of climate change. For example, in the 2011 floods in Bangkok, Thailand, more than 500 people lost their lives, and exponentially more suffered significant losses to their livelihoods. While all coastal cities face such threats, the impact on those with populations of 10 million inhabitants will be substantial. Estimates without extensive adaptation efforts, a 1-meter sea-level rise in New York could not only inundate coastal areas but have a devastating impact on the subway system, sanitation facilities, power plants, and factories, thereby affecting the economy of the city.
Moreover, to experiencing the effects of climate change, cities disproportionately contribute 70% of the world’s greenhouse gas emissions. Although they occupy just 2 percent of the land area. Intensified human activity in cities has led to increased greenhouse gas pollution while the capacity of oceans and vegetation to absorb them is declining. The urban ecological footprint in both developing and developed countries is on the rise with the increasing use of fossil fuels for transportation and construction, large-scale industrial pollution, deforestation, and land-use changes, among others.
Affluence and increased demand for global services and products contribute to increasing environmental pressures. Lifestyle and consumption choices are profoundly changing the size, structure, and density of cities. While some cities in developed countries are shrinking, many urban centers in developing countries are experiencing rapid and largely uncontrolled population growth. This means that the demand for housing, basic urban services, and consumer goods is growing. A preference for suburban living hurts both rural and urban environments alike, as it disadvantages public transport and creates severe traffic congestion contributing to greenhouse gas emissions.
Understanding how urban centers contribute to climate change requires knowing how transport, buildings, heating/cooling systems, and other urban activities. The geography, climate, spatial form, and economic base of a city significantly shape energy use patterns and greenhouse gas emissions.