Much is riding on the UN Rio+20 summit. Many are billing it as Plan A for Planet Earth and want leaders bound to a single international agreement to protect our life-support system and prevent a global humanitarian crisis.
Inaction in Rio would be disastrous, but a single international agreement would be a grave mistake. We cannot rely on singular global policies to solve the problem of managing our common resources: the oceans, atmosphere, forests, waterways and rich diversity of life that combine to create the right conditions for life, including 7 billion humans, to thrive.
We have never had to deal with problems of the scale facing today’s globally interconnected society. No one knows for sure what will work, so it is important to build a system that can evolve and adapt rapidly.
Decades of research demonstrate that a variety of overlapping policies at city, subnational, national and international levels is more likely to succeed than are single, overarching binding agreements. Such an evolutionary approach to policy provides essential safety nets should one or more policies fail.
The good news is that evolutionary policymaking is already happening organically. In the absence of effective national and international legislation to curb greenhouse gases, a growing number of city leaders are acting to protect their citizens and economies.
This is hardly surprising — indeed, it should be encouraged.
Most major cities sit on coasts, straddle rivers or lie on vulnerable deltas, putting them on the front line of rising sea levels and flooding in the coming decades. Adaptation is a necessity. However, with cities responsible for 70 percent of global greenhouse-gas emissions, mitigation is better.
When it comes to tackling climate change, the US has produced no federal mandate explicitly requiring or even promoting emissions-reductions targets. However, by May last year, about 30 US states had developed their own climate action plans, and more than 900 US cities have signed up to the US climate-protection agreement.
This grassroots diversity in “green policymaking” makes economic sense. “Sustainable cities” attract the creative, educated people who want to live in a pollution-free, modern urban environment that suits their lifestyles. This is where future growth lies. Like upgrading a mobile phone, when people see the benefits, they will discard old models in a flash.
Of course, true sustainability goes further than pollution control. City planners must look beyond municipal limits and analyze flows of resources — energy, food, water and people — into and out of their cities.
Worldwide, we are seeing a heterogeneous collection of cities interacting in a way that could have far-reaching influence on how Earth’s entire life-support system evolves. These cities are learning from one another, building on good ideas and jettisoning poorer ones. Los Angeles took decades to implement pollution controls, but other cities, like Beijing, converted rapidly when they saw the benefits. In the coming decades, we may see a global system of interconnected sustainable cities emerging. If successful, everyone will want to join the club.
Fundamentally, this is the right approach for managing systemic risk and change in complex interconnected systems, and for successfully managing common resources — though it has yet to dent the inexorable rise in global greenhouse-gas emissions.