New York City Could See 6-Foot Sea Rise, Tripling of Heat Waves by 2100

If left unconstrained, global warming could wreak havoc on the Big Apple

February 19, 2015 |By Colin Sullivan and ClimateWire

Heat waves and floods caused by climate change could mean disaster for the Big Apple's five boroughs by the end of the century, with sea levels now predicted by a new report to climb by as much as 6 feet by 2100.

According to the New York City Panel on Climate Change, an independent body composed of climate scientists, New York could see a 6-foot increase under a worst-case scenario that has been revised from previous estimates that 2 to 4 feet would be the maximum rise.

The report also marked a new estimate for how hot it could become within the next 80 or so years, with the panel projecting a temperature increase as much as 8.8 degrees Fahrenheit and a tripling in the frequency of heat waves by the 2080s in the city.

The report noted that temperatures in Central Park climbed at a rate of 0.3 F per decade from 1900 to 2013, totaling a 3.4 F rise, but the panel expects those figures to soar, with an increase of 4.1 to 5.7 F by the 2050s and 5.3 to 8.8 F by the 2080s.

The frequency of extreme precipitation is expected to jump, as well, with about 1½ times more events per year possible by the 2080s, the report said.

Coastal communities, like many on Staten Island and in low-lying Brooklyn and Queens, could be in particular jeopardy, with storms likely to alter local beaches and coastlines. To date, the city has already dumped 26,000 linear feet of sand along Staten Island's shorelines, for instance, but that number could pale in comparison with future adaptation needs, the report said.

The report is meant to help the city plan for climate change, including greenhouse gas emission reductions and making Staten Island's shores more resilient to storm surges and rising seas. New York has set a goal of cutting greenhouse gas emissions by 80 percent by 2050, and a series of projects are underway to harden the city's infrastructure.

The report also attempts to prod the Federal Emergency Management Agency into revising its 2013 preliminary flood insurance rate maps to reflect the panel's conclusion that new projections will roughly double the areas likely to be affected by a 100-year flood.

Future damage could double
For the 500-year flood, new sea-level-rise estimates by 2100 increase the affected areas by 50 percent compared with FEMA's 2013 estimates, the panel said.

All this is why the report's authors are urging FEMA and the administration of Mayor Bill de Blasio (D) to heed the warnings contained in the exhaustive study.

Kim Knowlton, senior scientist at the Natural Resources Defense Council and a co-author of the report's chapter on public health, said the report marks new territory because it extends previous research out to 2100 for the first time.

She added that FEMA in particular should take note lest New York strand as many people as were stranded when Superstorm Sandy hit in late 2012. Knowlton said as many as 300,000 people were "inundated" by Sandy outside FEMA'S flood-risk zone.

"These are better maps," she said of the maps in the panel's report. "They include more of the available science on climate change."

As for what comes next, Knowlton said she is optimistic de Blasio will take the projections seriously, despite some thought within the environmental community that the progressive mayor has been more readily drawn to issues like income inequality and race relations.

"What the city has on paper are fantastic plans," she said. "New York City is a world leader on [climate change]. This mayor has climate change in his sights."

Pressed further on whether de Blasio has made the environment a priority, Knowlton added, "Let's keep watching and helping and encouraging. We'll all be working together to both help and encourage this administration into action."

One area in which Knowlton would like to see added emphasis is urban heat island effects. She said the city can do much more to turn black rooftops white and change the built environment so less heat is radiated back into the atmosphere at night. She said these issues are essential to help low-income communities adapt.

Click here to read the report.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500