How Climate Change is Already Affecting the World's Major Cities

Conor Riffle

As the U.S. sees increased severity and frequency of hurricanes and tornadoes, there is perhaps no timelier reminder that the world's cities face devastating impacts from climate change.

More hot days and heat waves, more intense rainfall, bigger and stronger storms and floods -- these are the climate change risks most frequently reported by city governments in a new report by the Carbon Disclosure Project (CDP). This new report details how the world's largest city governments -- the cities of the C40 Cities Climate Leadership Group -- are tackling climate change.

Nearly all of the cities reporting to CDP consider themselves at risk from climate change, and 43 percent said they are already dealing with the immediate effects in their cities. The implications for buildings, infrastructure, energy supply, water availability and human health are significant.

Jakarta, when hit by floods in 2007, for example, experienced a total financial loss of US$879 million, and more than 200,000 refugees. In Rio de Janeiro, Brazil, intense rainfall in 2010 damaged infrastructure and affected waste management, transportation and communications, while spreading disease in flooded areas. New Orleans is still dealing with the impacts of Hurricane Katrina and the large number of blighted properties that it left in its wake.

What of future risks? New Orleans will lose significant parts of the city from sea level rises should climate change continue on its current path. In Karachi, Pakistan, 60 percent of residents live in slum areas and do not have the adequate facilities to sustain the heat waves. In Lagos, Nigeria, unmitigated climate change will displace residents as a result of flooding, cause water shortages due to salt water intrusion, compound problems with waste management and human health and stress.

The consideration of climate-related risk will also play an increasing role in businesses' location decisions. Seventy-nine percent of cities reporting to CDP believe that the physical impacts of climate change could directly or indirectly threaten the ability of local businesses to operate successfully. As cities grow, maintaining safe, resilient environments for people and business will be increasingly important.

The high number of cities demonstrating awareness of the potential dangers from local climate impacts are taking a crucial step on the road to climate resilience. It is only from awareness of where a city is at its most vulnerable, or where it has the potential to make energy efficiency savings, for example, that steps to management can be most effectively taken. Twenty-three cities revealed to CDP that they have plans to increase their resilience by protecting infrastructure, business sectors and citizens against extreme weather events. Seven out of 10 North American cities reporting to CDP are among these.

City governments sit at a critical climate change nexus for several reasons. They are responsible for large amounts of greenhouse gas emissions (GHG). Their populations and infrastructure are immensely vulnerable to the damaging effects of catastrophic storms, sea level rises and warming temperatures. They are often also well positioned to act quickly due to their governmental structures. As such, a number of cities have pioneered extraordinary approaches to GHG reduction and climate resilience.

As New York City Mayor and C40 Chair, Michael R. Bloomberg states in the CDP report, "There is no single solution for confronting global climate change. Still, the best scientific data tells us that it is long past time to address this challenge, and that cities must lead the way."

Image CC licensed by Flickr user Burning Image.