On February 17, 2009, New York City Mayor Michael Bloomberg announced the release of New York City-specific climate change projections developed by the New York City Panel on Climate Change (NPCC) that show climate change poses real and significant risks to New York City. According to the report, New York City will face higher temperatures and more rapidly rising sea levels, as well as more frequent and intense extreme weather events – like heat waves, heavy rainstorms, and coastal flooding – over the course of the century. The report will be used to inform the actions of the City's Climate Change Adaptation Task Force, which was appointed last summer and is made up of City, State, and Federal agencies, regional public authorities and private companies that control critical infrastructure in New York City.
Using global climate models and local information, the New York City Panel on Climate Change projects that by the end of the century New York City's mean annual temperatures projected to increase by 4 to 7.5 degrees Fahrenheit. Annual precipitation is also projected to increase by 5 to 10 percent, and sea levels to rise by 12 to 23 inches. Recent evidence, however, including accelerated ice melt in Greenland and Antarctica, suggests that sea levels could rise at a faster rate than projected by the existing models – potentially to 41 to 55 inches by the end of the century. While this “rapid ice-melt” scenario does not have the same level of confidence associated with it as those developed by the global climate models, the NPCC included it in their projections given the large impact it would have on the City should it occur.
The report also projects that extreme events – such as heat waves, short periods of intense rain, droughts, and coastal flooding – are likely to become more frequent and more intense. In contrast, cold day events, where the temperature drops below freezing, will decrease in frequency. By the end of the century, New York City could experience approximately 2.5 to 4.5 times more days per year over 90 degrees than experienced on average from 1971-2000; approximately 2.5 to 4 times more heat waves (as defined as three consecutive days over 90 degrees) a year than experienced on average from 1971-2000; more frequent, intense rainstorms; a current 1-in-10 year coastal flood about once every 1 to 3 years; and a current 1-in-100 year coastal flood about once every 15 to 35 years.
The NPCC was charged with developing climate change projections for New York City and tools to assist the City’s Climate Change Adaptation Task Force. The first of these tools, the Climate Risk Information Workbook, which contains detailed climate change projections for New York City primarily based on global climate model simulations, was released on February 17. The report will be used by the Climate Change Adaptation Task Force, which consists of 38 City, State, and federal agencies, regional public authorities, and private companies that operate, maintain and regulate critical infrastructure in New York City. The Task Force, which was also launched in August 2008, is working to identify the risks and opportunities posed by climate change and will release an initial report on its findings and draft adaptation strategies later this year. A copy of the report is available at http://www.nyc.gov/html/om/pdf/2009/NPCC_CRI.pdf. (New York City Mayor’s Office Press Release February 17, 2009).