Cleansing the Atmosphere Spurs Global Warming

Working with data obtained over the last three decades at 342 meteorological stations scattered throughout Europe, Vautard et al. (2009) analyzed the frequency of occurrence of low horizontal visibility conditions at 0300, 0900, 1500 and 2100 Universal Time, comparing their results with concomitant changes in near-surface air temperature, as well as with spatial and temporal variations in sulfur dioxide emissions. Their reason for doing so, of course, was that "by enabling less energy to be received at the surface during daytime," as they describe it, "the low-visibility phenomenon inhibits surface heating, and therefore induces a lower local temperature." Consequently, since low-visibility conditions were presumed to have declined over the three-decade period, due to the implementation of more effective air pollution control measures, it was anticipated that a temporal warming trend would be evident in the temperature data.

The three researchers state that the major accomplishment of their study was their documentation of "a massive decline (about 50% in 30 years) of low-visibility occurrence throughout Europe," and they report that this decline was "spatially and temporally correlated with trends in sulfur dioxide emissions, suggesting a significant contribution of air-quality improvements" to the improvement in visibility. In addition, they did indeed find that by statistically linking local visibility changes with temperature variations, "the reduction in low-visibility conditions could have contributed on average to about 10-20% of Europe's recent daytime warming and to about 50% of eastern European warming."

A major implication of the three researchers' findings is that the cleaning-up of European air pollution over the past three decades has been responsible for much of the significant warming of that part of the planet over the same time span; and this observation leads to the uncomfortable conclusion that the cleansing of the continent's air has exacerbated the many dire consequences that are routinely predicted by climate alarmists to result from global warming (if one believes what the world's climate alarmists say in this regard).

There is, however, hope for the future (if one is worried about this state of affairs), for Vautard et al. write that air quality in Europe has improved so much over the last two decades, "owing to emission control policies," that there is now "less hope for further improvements" in this area, which thus suggests there will be less of an air-cleansing-induced warming in Europe's future, so that less hope equals more hope!