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Ecological Changes in Tropical Montane Cloud Forests: Harbingers of Global Warming?
Foster, P.  2001.  The potential negative impacts of global climate change on tropical montane cloud forests.  Earth-Science Reviews 55: 73-106.

In our Editorial of 21 November 2001, we described how a pair of papers published in Nature back in 1999 blamed global warming for wreaking havoc on tropical montane cloud forests, particularly in the highland areas of Monteverde, Costa Rica, after which we described a new study (published in Science), which convincingly demonstrates that the actual cause of the ecological disruptions observed there was the past century's deforestation of upwind lowlands. We here review a newer paper produced by one of the authors of one of the Nature papers that was written and accepted for publication long before the appearance of the recent Science study and which thus still holds to the old view of the issue.

What was done
In a major review paper, the author (astrophysicist Pru Foster) describes some of the special features of tropical montane cloud forests, emphasizing the negative impacts she and others believe global warming may have on these unique ecosystems.

What was learned
Among other things, Foster draws attention to potential increases in "dry seasons, droughts, hurricanes and intense rain storms, all of which might increase damage to the cloud forests."  She also suggests that "coming climate changes appear very likely to upset the current dynamic equilibrium of the cloud forest," resulting in "biodiversity loss, altitude shifts in species' ranges and subsequent community reshuffling, and possibly forest death."  Foster notes, for example, that global climate models predict "altitude shifts in the climatic optimum for mountain ecotones of hundreds of meters by the time of CO2 doubling," which she says implies the "complete replacement of many of the narrow altitude range cloud forests by lower altitude ecosystems, as well as the expulsion of peak residing cloud forests into extinction."  In the case of the Monteverde Cloud Forest in Costa Rica, she states that these ominous changes are already underway, i.e., that "the height of the cloudbank is already rising, resulting in less cloud immersion, and thus driving local extinctions through enhanced dryness," calling the intense sensitivity of the cloud forest "an early warning system" of worse things to come.

What it means
"Perhaps the warning bell is already ringing," says Foster with respect to the ecological changes observed in the Monteverde Cloud Forest; and in this assessment she is correct.  But of what it warns us is not what she contends.  Her ignorance of the new thinking on the subject (at the time she wrote her review) tends to draw our attention from the real cause of the various biological perturbations in the former land of mists (deforestation of upwind lowlands) to a purported problem (CO2-induced global warming) that is likely unreal, insoluble (if it were real) and (in any case) a monetary black hole - to put it in astrophysical terms Foster should clearly understand - into which we can eternally throw ungodly amounts of money and never see a glimmer of a return on the "investment," which, of course, keeps us from effectively dealing with the true cause of the local climate changes and ensuing ecological perturbations.

Yes, the "canary" of the Monteverde Cloud Forest "coal mine" is sending us a message, alright; but it is not one of impending disaster due to CO2-induced global warming (again, see our Editorial of 21 November 2001).  Rather, it is telling us that certain of the local activities of man are having significant deleterious local consequences.  Clearly, if we all took care of our own backyards, the earth would have no trouble taking care of itself.