N.Y. Climate May Be in Hot Water

New York City, the nation’s densest urban center, is armored with heat-retaining concrete and stone, and so its median temperature hovers five to six degrees above the regional norm. The city, a New York report on global warming predicts, will grow warmer still. Within 70 years, New York will have as many 90-degree days a year as Miami does now.

If temperatures and ozone levels rise, the report says, the poor, the elderly and the young--especially those in crowded, poorly ventilated buildings--could suffer more heatstroke and asthma.

But such problems might have relatively inexpensive solutions, from subsidizing the purchase of air conditioners to planting trees and painting roofs light colors to reflect heat.

“The experience of southern cities is that you can cut deaths and adapt rather easily,” said Patrick Kinney of the Mailman School of Public Health at Columbia University, who co-authored the federal report on the possible effects of global warming on the Northeast.

Rising ocean waters present a more complicated threat. The seas around New York have risen 15 to 18 inches in the last century, and scientists forecast that by 2050, waters could rise an additional 10 to 20 inches.

By 2080, storms with 25-foot surges could hit New York every three or four years, inundating the Hudson River tunnels and flooding the edges of the financial district, causing billions of dollars in damage.

“This clearly is untenable,” said Klaus Jacob, a senior research scientist with Columbia University’s Lamont-Doherty Earth Observatory, who worked on the New York report and is an expert on disaster and urban infrastructure. “A world-class city cannot afford to be exposed to such a threat so often.”

Jacob recommends constructing dikes and reinforced seawalls in lower Manhattan, and new construction standards for the lower floors of offices.