Editorial Comment by Tom Davey
Trees have long been an icon of environmental purity, taking in carbon dioxide and exchanging it for life-sustaining oxygen. But nothing is sacred these days. Our forests might actually be emitting air pollutants according to an Oregon professor, Dr. Reinold Rasmussen, a 62 year old geologist turned botanist. He embarked on a decades-long study of trees and their emissions and felt that his suspicions were confirmed after studying the blue hazes which begat the names of Virginia's Blue Ridge Mountains and Uganda's Blue Valleys.
Conventional wisdom held that trees were not believed to emit significant amounts of hydrocarbons. Indeed, many scientists have long been dismissive of Dr. Rasmussen's claims that some trees might actually be contributors to the smog problem. Environmental scientists have always concentrated on industry and auto emissions as smog sources. But I checked around with a few learned people recently, and found that, yes, trees do give off isoprenes, terpenes and other hydrocarbons.
My sources stressed while all plant life imbibes CO2 and emits oxygen, trees are unmatched botanical mechanisms for performing this life-sustaining miracle. But, it should be noted, even oxygen is toxic in certain dosages. So much for the childlike mantra environment friendly. (Surely in physics the ideal should be environment neutral).
One amusing story emerged from discussions on the validity of Dr. Rasmussen's thesis. The Ontario Ministry of Environment once had a sophisticated but portable air pollution monitoring vehicle named TAGA (Trace Atmospheric Gas Analyzer). They tried to calibrate it at the MOE labs in Rexdale and in other Toronto-area locations, but the ambient air pollution in the area made calibration difficult. The TAGA vehicle was then driven to Dorset, a lovely area in Ontario's cottage country, famed for its lakes, forests and the purity of its air. Goldie Hawn, Kurt Russell, Steven Spielberg, Martin Short and Arnold Schwarzenneger, are among the celebrities who have been drawn to this area to escape the smog of Los Angeles.
But even in this veritable Eden of forests and lakes, calibration of the air monitoring equipment proved difficult. Terpenes, isoprenes and other chemical emissions from the abundant forests registered on the TAGA's sensitive instruments like an atmospheric seismograph. So, perhaps Dr. Rasmussen's work did not deserve his detractors' scorn.
He is certainly an interesting character. A devotee of Charles Darwin, he took heart from the fact that his hero had also inspired disdain and abuse for his findings on evolution. Darwin had been reluctant to publish his findings for many years, probably because he feared the ire of church officials. He acted only after being spurred on by the fact that Wallace, another Englishman, was about to publish his findings on his evolutionary research in South America. Only then did Darwin publish his Origin of Species, many years after his historic voyage on The Beagle. Abuse from many sides was heaped upon Darwin before he rightfully took his place among the greatest scientists of all time.
In his experiments with trees, Dr. Rasmussen wrapped certain branches with plastic bags and claimed to capture significant amounts of isoprene and other hydrocarbons major contributors to the chemical conditions which cause smog. Even when he published his first findings three decades ago, few scientists took notice.
Diverted into other air pollution issues, he embarked on travels around the world. In his quest to curb air pollution he enthusiastically focused on CFCs, the chlorofluorocarbons, which had saturated the atmosphere ever since they had been introduced some seven decades earlier under the trade name Freon.
While the manufacture of chlorofluorocarbons has been banned for years, they are probably the most ubiquitous atmospheric chemical on our planet and the main culprit of ozone depletion in the stratosphere. Indeed, some scientists estimate that one CFC molecule can destroy as many as 100,000 ozone molecules. While a significant minority of scientists remain unconvinced about the seriousness of global warming, virtually none will dispute the fact that ozone depletion is extremely dangerous to humans, animal life and certain crops.
In his quest for Freon-free air, Dr. Rasmussen went to heroic lengths to find, then sample, 'antique air', such as air which had been trapped in old Japanese glass floats used by fishermen and so was free from the CFC contamination. Even old wines, where air had been trapped between the wine and the corks, attracted his attention.
Dr. Rasmussen's work on the smog-creating chemicals from trees has recently attracted notice in such serious papers as the Wall Street Journal and the Globe & Mail. After literally and figuratively working in the wilderness for decades, his research is now said to be impacting on US federal air pollution policies.
But air pollution from trees is not exactly a new idea in Washington circles. President Reagan, famous for his off-hand comment "if you've seen one redwood, you've seen them all", had once said that trees might emit forms of air pollution. His remark made many years ago was dismissed as the ravings of an industry-driven, anti-environmentalist President. Protesters responded with a theatre of the absurd, by demonstrating while decked out as trees, each carrying signs which pleaded with the President: Cut me down now before I kill again!