Rising Temperatures Will Lead to Increase in Hurricane Sandy-Like Floods

The study found that New York City can expect two Hurricane Sandy-like floods per decade by the year 2100 if global temperatures rise 1.5 degrees Celsius above pre-industrial levels, and three such events per decade if temperatures rise to 2.0 and 2.5 C.

Credit: DJ Rasmussen, Princeton University

The study, conducted by researchers at Princeton University and colleagues at Rutgers and Tufts Universities, the independent scientific organization Climate Central, and ICF International, was published in the journal Environmental Research Letters on March 15, 2018.

“People think the Paris Agreement is going to save us from harm from climate change, but we show that even under the best-case climate policy being considered today, many places will still have to deal with rising seas and more frequent coastal floods,” said DJ Rasmussen, a graduate student in Princeton’s Program in Science, Technology and Environmental Policy in the Woodrow Wilson School of Public and International Affairs, and first author of the study.

The researchers found that higher temperatures will make extreme sea level events much more common. They used long-term hourly tide gauge records and extreme value theory to estimate present and future return periods of extreme sea-level events through the 22nd century. Under the 1.5 C scenario, the frequency of extreme sea level events is still expected to increase. For example, by the end of the 21st century, New York City is expected to experience one Hurricane Sandy-like flood event every five years.

Extreme sea levels can arise from high tides or storm surge or a combination of surge and tide (sometimes called the storm tide). When driven by hurricanes or other large storms, extreme sea levels flood coastal areas, threatening life and property. Rising mean sea levels are already magnifying the frequency and severity of extreme sea levels, and experts predict that by the end of the century, coastal flooding may be among the costliest impacts of climate change in some regions.

Future extreme events will be exacerbated by the rising global sea level, which in turn depends on the trajectory of global mean surface temperature. Even if global temperatures are stabilized, sea levels are expected to continue to rise for centuries, due to the fact that carbon dioxide stays in the atmosphere for a long time and the ice sheets are slow to respond to warming.

Overall, the researchers predicted that by the end of the century, a 1.5 C temperature increase could drive the global mean sea level up by roughly 1.6 feet (48 cm) while a 2.0 C increase will raise oceans by about 1.8 feet (56 cm) and a 2.5 C increase will raise sea level by an estimated 1.9 feet (58 cm).

Contacts and sources:
Catherine Zandonella