At the United Nations General Assembly this month, President Obama called on each of the world's countries to shoulder its share of responsibility for a "global response to global challenges." Few of these challenges are more daunting or imbued with possibility than the global demographic shift taking place in metropolitan regions.
Consider this: A century ago, one out of ten people lived in cities. This year, for the first time, a majority does. By 2050, the United Nations projects, almost three-quarters of the world's population will call urban and metropolitan areas home. Most of this increase will occur in developing countries, where nearly three of five people will live in cities by 2030.
In the United States, this trend is long underway. Today, America's largest 100 metro areas -- that is, cities, suburbs, and the rural areas that surround them -- cover only 12 percent of the country's land but account for 65 percent of our population and 75 percent of our economic output. America's cities are growing, but their suburbs and exurbs grow twice as fast, and the success of all three is increasingly interconnected.
In emerging economies, urbanization is more pronounced as megacities of Sub-Saharan Africa, Southeast Asia, and Latin America anchor dynamic industries and burgeoning markets and attract enormous numbers of immigrants. Every day, thousands of people journey from village to city and farm to factory. In many places, processes of industrialization that took two centuries will transpire in just two decades.
As a consequence, increasing numbers of people are within reach of dramatic social and economic progress, but also vulnerable to overburdened infrastructure, inadequate housing, and outmoded health systems. In fact, UN-HABITAT projects that within three decades, one of three people will live in near total despair -- lacking sanitation and clean water, exposed to the imminent effects of climate change, fueling the spread of disease and possible pandemics. In a globalized world, the impact is clear for America's security and economy alike.
To help coordinate a global response, the United States today hosts World Habitat Day for the first time, with crucial support from the U.S. Department of Housing and Urban Development, Rockefeller Foundation, and fifty other organizations. This year's theme, "Planning our Urban Future," reflects the inescapable facts that life in the 21st century will be markedly more metropolitan and interdependent. It represents the extraordinary opportunity for communities to become field laboratories for new solutions -- to grow more resiliently, equitably, and sustainably. It sets a simple question in sharp relief: Will we shape the historic forces driving billions of people to metro regions or will we let these forces shape us?
The time has come for renewed American innovation, investment, and leadership. President Obama is pursuing a robust sustainability agenda: creating green jobs and products, facilitating energy efficient homes and buildings, and implementing policies that tie the quality and location of housing with access to good jobs, quality schools, and safe streets.
But in the 21st century, effective action also counts on and catalyzes the ideas, resources, and civic capital of others. Washington has neither a monopoly on solutions nor the desire - let alone the ability - to solve these challenges alone. Instead, we must lead by listening and learning.
Think about advances underway. Durban, South Africa, incorporates ongoing climate change assessments, adaptation, and mitigation into long-term city planning. Stockholm, Dublin, Singapore, and Brisbane are developing smart transportation systems that reduce traffic and greenhouse gas emissions.
America is breaking new ground too. Denver's new multi-modal transit system, for instance, links downtown to surrounding communities. Rejecting traditional city-suburb tensions, it demonstrates that cities and suburbs not only share problems, but can also collaborate on solutions.
In our own partnership during the last several years, we have shown what can happen when local governments and foundations establish laboratories of urban reform. In New York City, the Rockefeller Foundation, Bloomberg administration, and others created the Affordable Housing Acquisition Loan Fund to build and preserve 30,000 affordable housing units over 10 years. Starting with only $8 million in government funding, this alliance raised more than $24 million in foundation funding to leverage $190 million in private capital -- connecting private developers who want to provide affordable units with hard-to-find seed financing to bring their plans to life. It earned a coveted "Innovation in American Government" award from the Ash Institute at Harvard's Kennedy School of Government this past fall and is now being replicated across the nation.
As World Habitat Day welcomes leaders from around the globe to the nation's capital in advance of the World Urban Forum in Rio in 2010, we face a decision: Either we watch idly as the world transforms around us -- depleting natural resources, jeopardizing national security, and impeding access to global markets -- or we lead by example. Working together, America will make the right choice.
Shaun Donovan is Secretary of the United States Department of Housing and Urban Development and was Commissioner of the New York City Department of Housing Preservation and Development from 2004 to 2009. Judith Rodin is President of the Rockefeller Foundation.