At this, the height of a very warm summer and in the midst of a year that's predicted to become the hottest on record, it's clear that cities are major contributors to climate change. While urban residents are vulnerable to the so-called heat island effect, cities also offer great promise for solutions. The challenge for public health researchers is to realize the potential of cities as vibrant living laboratories that can demonstrate and generate ingenious innovations to benefit population health.
The need for urban solutions for global warming is as great: the compactness of cities magnifies their impact on climate change, leaving millions vulnerable to its deleterious effects. Cities cover less than 2 percent of the earth's surface, according to the United Nations, yet they produce more than 60 percent of all carbon dioxide. And they are growing—with six out of every 10 people in the world expected to reside in urban areas by 2030.
The effects of this urban population surge are exacerbated because cities tend to be coastal, increasing their exposure to storms and flooding and, in turn, magnifying the outsized liability of disadvantaged urban communities. "Climate change and poverty are inextricably linked," writes the World Bank. "Without rapid, inclusive and climate smart development, climate change could see more than 100 million more people living in poverty by 2030."
These conditions underscore the risks to all of our health, which is jeopardized by dramatic changes in weather, dangerous living conditions, and poverty. Anticipating those risks, preparing for them, and responding to them is the work of public health, and it's crucial to addressing climate change.
Fortunately, cities are innately suited to become innovative climate solution hubs. For centuries, they have been efficient delivery systems for public health benefits. Populations that live together in great numbers enjoy economies of scale in public transportation, distribution of goods, and stable housing. Direct health benefits that come from clean water, access to food, and sanitation systems add to that cost effectiveness. Culturally, cities align diverse groups of people, catalyzing the rich exchange of ideas that often leads to novel solutions. How can the benefits of population density be deployed against the health effects of climate change?
As one first step, cities must plan for a more efficient future. The Guardian writes:
Compact urban growth can create cities that are economically dynamic and healthy. The Global Commission on the Economy and Climate, a partnership led by 28 business leaders and former heads of state, and its flagship New Climate Economy project (NCE), found that compact, connected and coordinated cities are more productive, socially inclusive, resilient, cleaner, quieter and safer. They also have lower greenhouse gas emissions—a good example of the benefits of pursuing economic growth and climate action together.
With the right fiscal tools, we can allow cities to make themselves more energy efficient, as former New York City Mayor Michael Bloomberg and Paris Mayor Anne Hidalgo write jointly in The Huffington Post: "The more nations empower their cities, the bolder they will be. Cities with authority over building energy standards, for instance, deliver three times the results of cities that lack such power."
Michael Bloomberg, now the UN Secretary General's Special Envoy for Cities and Climate Change, also notes that, "if the world's cities took bold actions to reduce emissions, their collective impact would be equal to halving global coal use over the next 40 years."
Key to developing solutions can be the C40 Cities, a network of the world's megacities committed to addressing climate change. The C40 Cities Climate Leadership Group, now in its tenth year, provides an important vehicle in this regard, connecting more than 80 of the world's greatest cities, representing more than 600 million people and one quarter of the global economy.
The C40 Cities and their mechanisms can be important focus and vehicles for tackling climate change locally with a focus on maximizing benefits to health, and creating research-based innovations that can be replicated around the world.
It's time to see cities as living laboratories for climate change solutions. There's no time to waste in empowering them in this vital role.