The world’s cities are at the greatest risk from climate change socially and economically. Each city will face its own challenge based on their regional location and may experience increased incidence of drought, flood, extreme heat or cold, and extreme weather events. Many cities are built near large bodies of water, including oceans and rivers, which increases the threat of rising sea levels. Cities in the developing world, especially South Asia and sub-Saharan Africa, have additional challenges in that they are exploding in population, but do not have the infrastructure or resources to keep up with the day-to-day requirements of running a city, never mind funding adaptation strategies in response to climate change. Millions of people live on the margins of most large cities and are most exposed to the impact of weather events. One only need look at Haiti, an under-resourced country that has suffered a catastrophic earthquake and two hurricanes for an example of development needs and human suffering.
The developed countries have a different problem in responding to climate change. Most cities have an aging infrastructure, inefficient housing stock, and a haphazardly built energy grid. Many of these elements will need to be improved or replaced in the coming decades and will need to be reinforced to withstand the greater likelihood of extreme weather, and insulated to not only reduce GHG emissions, but also to protect against extreme temperature variations. Transportation systems, including roadways and mass transit, are also at threat to climate change.
Today more than 50 percent of the world’s population lives in cities and this number will continue to grow as we move away from an agrarian-based economy. Cities are also the biggest polluters and collectively contribute 70 percent of global greenhouse gas (GHG) emissions. However, the challenge of creating new and updating existing infrastructure provides a real opportunity to adapt and mitigate climate change. The World Bank estimated that climate-proofing new construction may add 1-2% to the total budget, but this up-front cost is a long-term investment against future events. These large projects will require substantially financing and most cities may need public private partnerships to achieve results. One sector they may look to partner with is the insurance industry, which will need to create a new model to pay out for environmental catastrophes that can cost in the billions; we can avoid some of those future costs by adapting now.
There are already many known solutions but need financing, time, construction policies, and political motivation to implement them. However, some very simple and inexpensive steps can also be taken now. A prime example is in green building practices. Increasing green spaces in cities with roof gardens, vertical wall gardens, parks and bioswales provides an inexpensive measure with multiple benefits that have economic savings. These include absorbing storm water runoff saving on wastewater treatment, cleaning air pollution that reduces healthcare costs, heat island mitigation that reduces energy costs, absorbing GHG emissions which mitigates climate change, and also provides space to protect biodiversity. An additional benefit is that green spaces are aesthetically pleasing and can increase property values. Some cities have implemented these ideas for budgetary, as well as environmental, reasons, including Berlin, Denmark, Philadelphia, and my home town of New York City.
A takeaway is how to help cities in developing countries create sustainable infrastructure now, instead of building on the foundation of past building practices. Many of these cities are growing exponentially and need to provide living space for the millions of people who are flocking to economic hubs for employment and other opportunities. A question is how to guide their building practices, policies, and notably how to finance them. We may look at the financing mechanism of the United Nations Framework Convention on Climate Change (UNFCCC), which provides money to developing countries for climate change adaptation as a potential source. We have an ethical duty to assist these countries, as well as insure against a future where climate refugees will flood into the developed countries. We have seen Europe nearly destabilized by the Syrian refugee crisis, where more than a million people have fled a war-torn country. Millions more may be displaced by climate change. How do we work together to prevent a future humanitarian disaster?