Related
Why Files:
POSTED 20 AUG 1998 It's been a long, hot summer. Amarillo, Texas, had 13 days with temperatures above 100 degrees Fahrenheit. May and June were scorchers, setting records in Texas, Arkansas, Louisiana and Florida. Texas had little measurable rainfall from April through June. The Lone Star State, along with Oklahoma, Georgia and Florida, is under a federal drought emergency.
Workers repair heat-warped railroad tracks in Watauga, Texas, where 13 cars derailed Aug. 2, 1998. Texas' blistering heat was blamed for ``sun kinks'' -- warped stretches of railroad track -- that caused two unrelated derailments in North Texas. Workers are riding the rails to find any more rough areas. AP Photo/LM Otero.
A huge water main even broke in Texas, caused by shifting of soil due to the drought. And for the first time in history, the president has released federal funds to buy air conditioners and fans for heat-stricken citizens.
And now comes news that, globally speaking, July is the hottest month in recorded history. Planetary temperatures were about one-half degree Fahrenheit warmer than the previous record, set just a year ago.
The Why Files got to wondering (which we're paid to do): Does this heat wave signify global warming, as vice-president Al Gore contends? And what kind of technological fixes could avert the soaring global temperatures forecast by climatologists?
Global warming is the predicted increase in global temperatures due to the accumulation of greenhouse gases, particularly carbon dioxide, a byproduct of combustion. The warming could boost average temperatures between 1.8 and 4.5 degrees F by 2100 (some estimates go as high a 8.1 degrees), according to an international scientific panel.
But that slight rise could mask serious increases in heat spells, like the one that's gripped the southern United States. Reason is, when the average temperature rises slightly, as it has been doing for decades, the number of days with extreme temperatures increases much faster. Adding to the confusion, The Why Files learned this week that scientists have detected an error in satellite records of the Earth's temperature. The glitch apparently depressed atmospheric temperature readings, strengthening the case for global warming. Here's a report on extreme weather so far in 1998.
Ambiguous signal
Nobody can say for sure whether the current heat wave reflects global warming. Notes Rob Qualye, who heads the global climate lab at the National Climatic Data Center, "It's impossible to attribute any single event to global warming."
Courtesy National Oceanographic and Oceanic Administration.
Still, 1998 is likely to be even hotter than 1997, the global bake-off champion since climatic records began about a century ago. Furthermore, the global average temperature for each of the first seven months of 1998 exceeded the previous record for that month.
Climatologists, like other scientists who can't do controlled experiments, know to hedge their pronouncements. Here's how Qualye assesses the possible relation between the heat wave and global warming: "We are seeing something that is consistent with what's been modeled, with our predictions of what will happen."
He defers to a 1995 declaration by the Intergovernmental Panel on Climate Change that "observations suggest a discernible human influence on global climate." But he adds that other evidence, like the retreat of glaciers and the rise in sea level, also suggest that global warming is under way.
A sticky business
Conclusion? One hot summer doesn't prove global warming -- but it sure doesn't disprove it, either. We could blather on about how global warming could disrupt farming, industry, human health and nature. Instead, let's crank up the air-con and dig into some cool ideas for easing up on the planetary thermostat. Since carbon dioxide is the major greenhouse gas, we'll stick to no- and low-carbon energy alternatives.
The Why Files covered the climatologists' toolbox. Want more data on the state of our climate?
