How Global Warming Is Making Hurricane Irene Worse

http://thinkprogress.org/green/2011/08/26/305265/how-global-warming-is-making-hurricane-irene-worse/

By Brad Johnson on Aug 26, 2011 at 4:12 pm

Hurricane Irene is bearing down on the Outer Banks of North Carolina as a Category Two storm, [fortunately, is decreased to a Category One storm, although there is still much destruction going on from this giant] and is expected to track a path of destruction up the densely populated Atlantic coast, with New York City Mayor Michael Bloomberg ordering the first-ever mandatory evacuation of low-lying areas of the city. As the U.S. government report “Global Climate Change Impacts in the US” summarized in 2009, warming of the oceans is causing Atlantic hurricanes to become more intense and dangerous:

The destructive potential of Atlantic hurricanes has increased since 1970, correlated with an increase in sea surface temperature. An increase in average summer wave heights along the U.S. Atlantic coastline since 1975 has been attributed to a progressive increase in hurricane power. The intensity of Atlantic hurricanes is likely to increase during this century with higher peak wind speeds, rainfall intensity, and storm surge height and strength. Even with no increase in hurricane intensity, coastal inundation and shoreline retreat would increase as sea-level rise accelerates, which is one of the most certain and most costly consequences of a warming climate.

Below, ThinkProgress Green explores in more detail how Hurricane Irene has been made more destructive by the combustion of hundreds of billions of tons of fossil fuels.

Oceanic Warming. Greenhouse pollution is causing the world’s oceans to warm. Sea surface temperatures in the region where Hurricane Irene formed and along its track are around 0.5°C warmer than they were about 30 years ago.

[...]

This increased heat adds about 10 to 20 miles to the top potential speed of the hurricane’s winds. Storm surge increases proportionally to the square of the wind speed, meaning a 10 percent increase in hurricane wind speed means a 20 percent increase in storm surge.

[...]

More Atmospheric Vapor. As the world’s oceans have warmed, the amount of atmospheric water vapor has increased by about 4 percent. Rainfall rates due to hurricanes appeart to have increased by 6 to 8 percent since about 1970 in association with increased water vapor in the atmosphere and warming.

[...]

“These warm ocean temperatures will also make Irene a much wetter hurricane than is typical, since much more water vapor can evaporate into the air from record-warm ocean surfaces,” tropical meteorologist Jeff Masters explains in the Daily Beast.

[..]

Increased Extreme Precipitation. Because of greenhouse pollution, heavy rains in the United States have increased 14 percent over the 20th century, much greater than the increase in overall precipitation. This has been one of the wettest years in history for the Northeast, directly in the path of Hurricane Irene. Hurricane Irene’s wind and rain will more easily topple trees in the loose, saturated soil and flood rivers, reservoirs, and drains.

[...]

..