Chapter 3: Climate observations and projections

Abstract

Climate change is extremely likely to bring warmer temperatures to New York City and the surrounding region. Heat waves are very likely to become more frequent, intense, and longer in duration. Total annual precipitation will more likely than not increase, and brief, intense rainstorms are also likely to increase, with concomitant flooding. Toward the end of the 21st century, it is more likely than not that droughts will become more severe. Additionally, rising sea levels are extremely likely, and are very likely to lead to more frequent and damaging flooding related to coastal storm events in the future. The treatment of likelihood related to the New York City Panel on Climate Change (NPCC) climate change projections is similar to that developed by the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4, 2007), with six likelihood categories. The assignment of climate hazards to these categories is based on global climate simulations, published literature, and expert judgment.