Far too many people (recently Joan King, in her column 6 Nov. 2007) try to link the ongoing drought in Georgia to "man-made global warming." This is exactly the wrong thing to do, because this drought is almost certainly a climatic reaction to the ongoing La Niña event. This is caused by the sea surface temperature in tropical Pacific waters being considerably cooler than average.
The connection between SST and drought in the United States is made clear in "Causes and consequences of nineteenth century droughts in North America," by Richard Seager and Celine Herweijer of the Lamont-Doherty Earth Observatory at Columbia University. See the Web site for the full report.
The following paragraphs have been extracted, with permission: "From the mid 1850s to the mid 1860s, the West and Plains were struck by a severe drought. Years ago, David Stahle of the University of Arkansas had used tree ring analyses to suggest that, in Texas, this was the worst drought to strike in the last 300 years, worse than the Dust Bowl drought. During this time tropical Pacific SSTs were persistently colder than normal, a La Niña-like state. Geochemical coral records from the tropical Pacific confirm the existence of a persistent La Nina at this time.
"Locusts love drought. The worst swarms during the period of European settlement occurred in the 1870s. Once more, as for the drought a decade before, a cold tropical Pacific Ocean, La Niña-like conditions, prevailed. It is these SSTs that forced the changes in atmospheric circulation that created the 1870s drought over North America and created the conditions for the devastating locust swarms.
"The 1890s drought began in the late 1880s (following close on the severe winter in 1886 that killed vast numbers of cattle) and went on until 1896. The tropical Pacific forcing (cold SSTs - WTH), implicates the prevailing La Niña conditions.
"This work implicates ocean forcing as the cause of the droughts. When these (cool SSTs - WTH) create year after year of colder than usual SSTs, the atmospheric circulation adjusts in such a way that drought strikes North America."
As one can conclude from the findings, our current drought is not a "man-made" event at all, but a response to a fairly regular oscillation in SSTs, perhaps accented by emergence from the Little Ice Age, which ended sometime in the mid-19th century when global warming more or less began. The Younger Dryas cool era (that is, the end phases of the last "ice age") ended with an increase in global temperature of about 7 degrees Centigrade in one decade, 11,640 years ago (see the American Geophysical Union Web site).
The current La Niña event calls for cool heads and rational decisions regarding shared watersheds in responding to such major natural perturbations. Pointing to a nonexistent or hypothetical "man-made" cause is a political agenda, not fact-based.
W.T. "Ted" Hinds
Gainesville
Extending NAFTA to Peru is bad policy
I am disappointed that my congressman, Paul Broun, voted along with the bankers and the corporations to extend NAFTA to Peru. The previous NAFTA agreements have sent good jobs out of our country, displaced millions of poor farmers in Mexico, and undermined our efforts to protect the environment.
At the same time the Peruvian government repressed a strike by miners who were fighting for an eight-hour day. This takes us back to our own history when workers had to fight for the eight-hour day, plus protection from bad working conditions.
The agreement does nothing to protect all of us from unsafe imported products, including food. What it does is boost the profits of one company and an unpopular privatized system of Social Security.
I am proud of the 116 Democrats, a majority of the party, plus the few Republicans who voted the other way and passed the bill.
Adele Kushner
Alto