CO2 Fertilization?

Public comment about modeled environmental consequences by additions of carbon dioxide from fuel combustion borders on the hysterical, in our opinion. The gas, a trace gas in our atmosphere of 99% nitrogen and oxygen and an assortment of lesser gases, fertilizes green things, on land and in the oceans. Its historically low (yes, low) atmospheric concentration results largely from both land erosion and the simple fact that plants eat it and scavenge it. Indeed, the level of carbon dioxide in our air is barely above plant suffocation levels. And we in turn dine both directly and indirectly on green plants.

While browsing our old and new travel photos, we were struck by the difference in vegetation on a steep limestone mountainside above a famous lake in southern Switzerland, where in Lugano palm trees grow, and the large lake creates a consistent micro-climate of winter clear airs and summer hazes and thunderstorms. The first photo of the east side of rocky San Salvatore shows the difficulty that growing things have had on that virtually bare slope back in summer 1979, when air held 338 parts per million of carbon dioxide. The second photo, summer 2008, at 385 ppm carbon dioxide, shows that a great greening has come to that steep slope, with little to suggest that factors other than a small increase of less than 50 parts per million of carbon dioxide might be responsible.