Hurricane Sandy poses potential record-high river and coastal flooding risks for the U.S. East Coast next week. Meteorologists now say the likelihood of Sandy hitting the East Coast is increasing and that the storm may produce the worst weather conditions since the “Perfect Storm” of 1991. Given that global ocean temperatures during the first half of 2012 were the warmest on record, and Northeastern waters are currently 5° F above average, there is an unusually large amount of water vapor available to produce heavy rain and possibly a stronger storm.
Substantial evidence indicates that global warming may be responsible for the recent increasing intensity of Atlantic hurricanes, including increasing their size and contributing to a lengthening hurricane season. Out of the 11 most intense North Atlantic hurricanes ever recorded, five have occurred in the last eight years. Atlantic hurricanes have also grown stronger in recent years, a pattern consistent with climate change. Hurricanes storm surges now ride higher upon coastal seas that have risen over the last century due to global warming. This in turn amplifies damage where the surge strikes.
Some key facts on hurricanes and climate change:
• Of the 11 most intense North Atlantic hurricanes ever recorded, five have occurred in the last eight years (Wilma, Rita, Katrina, Dean and Ivan).
• The record-breaking rainfall dumped by Hurricane Irene in 2011 was the main impact of the storm in which flooding and other damage totaled over $15 billion, making Irene the 10th billion-dollar disaster in 2011 and the sixth most expensive hurricane in U.S. history.
• With more than $100 billion in damages, Hurricane Katrina remains the costliest weather-related disaster on record.
• In June 2012, tropical cyclone Debby produced record-breaking rainfall across Florida, in some locations dropping over 20 inches of rain in 24 hours. When Tropical Storm Debby formed on June 23, it was the first time ever that four storms formed before July since record keeping began in 1851.
• According to data from 2007, the number of category 4 and 5 hurricanes has increased by nearly 75% since 1970.
There is a strong scientific consensus that the most intense Atlantic hurricanes will become more frequent in the coming decades if greenhouse gas pollution continues to grow at a moderate rate. The increase in damages due to climate change will rise to an average of over $40 billion per year, as stronger hurricanes are exponentially more destructive than weaker storms.