The latest report from the UN Intergovernmental Panel on Climate Change(IPCC) addresses the role cities can play in dealing with climate change by cutting greenhouse gas emissions. Cities also face huge challenges related to global warming. This third of three reports was leaked ahead of the official release at an IPCC meeting in Berlin on Sunday.
Neither finding should be that surprising considering the statistics. Urban centers are responsible for about 75 percent of global energy use and produce 80 percent of greenhouse gas emissions that are known to contribute to global warming.
A substantial part of the world’s population lives in cities now, many of them in coastal areas and in flood plains. Sea-level rise threatens many large cities, including Los Angeles, New York, London, and Guangzhou.
That great concentration of people, and energy use and carbon pollution provides great opportunities. Cities can be made greener by retrofitting old buildings, to increase energy efficiency.
Simple measures like installing more installation, switching to energy-efficient lighting and buying improved boilers and furnaces would be easy energy efficiency steps. Those steps will not alone be enough. Those efficiency efforts need to be managed on a large-scale, above the level of buildings or even neighborhoods. Planning also needs to be customized for each city, according to Tim Dixon, a researcher on the Retrofit 2050 project.
Retrofitting buildings is a necessity for most cities because of the long life of the average building. Professor Dixon noted that about 80 percent of existing buildings will still be around in 2050. For that reason, Dixon recommends focusing on how to retrofit and protect existing buildings.
Retrofitting steps that make cities more efficient will only address one aspect of the climate change challenge. Cities around the world, both coastal and inland, will face huge challenges specific to their location, population density, and climate. Landlocked cities will still face challenges related to drought and river flooding.
Los Angeles, California is a huge, coastal metropolitan area home to about 12 million people. By 2050, the city’s infrastructure, museums, and historic buildings will be at risk from rising sea level according to a University of South California study released earlier this year.
Phyliss Grittman, lead author of the study, which was commissioned by the city and University of Southern California Sea Grant Program, says that Venice Beach and some parts of Wilmington and San Pedro are vulnerable to flooding now. The city, she says, will need to identify area s that tend to flood during storms and high tides now, and areas that are projects to be affected in the future.
Los Angeles is not alone in needing to prepare for the increased flooding that global warming is expected to produce. Huge coastal cities in the United States, Thailand, Indonesia, and China are under threat from any rise in sea level.
Cities that aren’t coastal, but prone to flooding now, like London and Guangzhou, China are also facing hugely expensive efforts to protect their populations.
A detailed analysis published by the U.S. National Oceanic and Atmospheric Administration gives a good summary of the scale of the problem, for coastal communities. Almost 60 percent of China’s 1.2 billion people live in 12 coastal provinces. By 2025, 75 percent of people in the United Sates will live in coastal counties. Coastal counties hold 20 of the countries largest urban areas, including Los Angeles, New York, and Miami.
Inland cities will also face adaptation challenges, but coastal cities will contain a greater percentage of the world’s population. Those cities and their people will be at increasing risk from floods and storms. Overall then, global warming poses a huge challenge to world cities, and by extension to a majority of the world’s population.
By Chester Davis