September 24, 2004
by Dennis T. Avery
Americans have sat transfixed during the last month as three big hurricanes in a row pounded in from the Gulf of Mexico.
Is it due to Global Warming?
The computerized global climate models predict we'll get more and bigger storms as the planet warms. The Worldwatch Institute says "heat in the atmosphere is the fuel that leads to stormy weather," and "weather disasters are occurring with ever-greater intensity and frequency around the world."
First of all, Worldwatch is blowing smoke, not providing information. Storms are not driven by heat but by the difference in temperatures between the equator and the Polar Regions.
All scientists agree that Global Warming is supposed to raise the temperatures at the poles about ten times faster than it raises them at the equator. So, global warming should decrease the temperature difference-and reduce the storm power. Oops.
A study of major hurricanes during in the last century (which has, on the whole, been a Warming) finds that "the number of intense and landfalling Atlantic hurricanes has declined." Oops again.
The world isn't even getting much Global Warming. Both the Arctic and the Antarctic have been cooling in the last several decades while the planet's overall temperatures have barely risen since 1940.
The satellites monitoring atmospheric temperatures find the warming trend is only about one degree Celsius every 300 years! Even Worldwatch can't claim much storminess from that.
Key question: Throughout history, have warmer climates led to bigger and more frequent storms? In a word, no.
Almost three times as many major hurricanes hit Bermuda, Jamaica, and Puerto Rico in the half-century between 1701 and 1850--during the depths of the Little Ice Age--as in the much warmer half-century from 1950 to 2000.
Sediments in a Florida Panhandle lake show only 12 category 4 and 5 hurricanes have hit that region in the last 7000 years. None of them hit during the warmest period, the Climate Optimum, which ended 5,000 years ago. In contrast, During the Little Ice Age, 1300 to 1850, lake sediments show category 4 and 5 storms hitting the region about once every 600 years.
Hurricanes Charley and Frances were category 2's when they made landfall and Ivan was a 3. They threaten more people--and do more costly damage--because we've built more homes and cities on our coasts.
Remember that the planet has been through Warmings before. Half of the last 10,000 years has been spent in the warming phases of the 1500-year climate cycles. Historic documents from the Roman Warming (200 BC to 600 AD) and the Medieval Warming (950 to 1300 AD) tell us that the climate was more stable and less stormy during the Warmings than during the cold phases-the Dark Ages and Little Ice Age.
The journal Natural Hazards did a special issue on storminess in 2003. Its experts found no increase in any type of storms during the last 150 warming years that could be tied to Global Warming. They did find a slight increase in total rainfall, because warmer air evaporates more water from the oceans to become rain or snow.
This year's hurricane season has been hard on coastal residents and not so great for those of us living along the Appalachian Mountains, which get the flooding from hurricane tails. Hurricane seasons are also cyclical. Fortunately, however, category 4 and 5 landfalls are very, very rare-and unlikely to happen as we head into our own natural, unstoppable Modern Warming.
But watch out for the next Ice Age.
Dennis T. Avery is based in Churchville, VA, and is director of the Hudson Institute's Center for Global Food Issues.
Home | Learn About Hudson | Hudson Scholars | Find an Expert | Support Hudson | Contact Information | Site Map
Policy Centers | Research Areas | Publications & Op-Eds | Hudson Bookstore
Hudson Institute, Inc. 1015 15th Street, N.W. 6th Floor Washington, DC 20005
Phone: 202.974.2400 Fax: 202.974.2410 Email the Webmaster
© Copyright 2013 Hudson Institute, Inc.