Tuesday, September 19, 2006

But the evidence that the human species is in a whole heap of trouble keeps piling up, like the research work in Amazonia (referenced in the Lovelock article) that suggests the world's largest rain forest is extremely sensitive to drought, and that many of its tree species probably can't survive more than three years of it. (Most of eastern Amazonia is currently in the second year of the worst drought on record.) If trees start to die en masse, the ground will be exposed to direct sunlight, which will dry out the soil, which will cause the understory to die, which will, within a very short period of time, create either an African-style savanna or a moon-like desert, depending on the amount of aluminum silicate in the soil.

If Amazonia dies, the enormous carbon reserves currently trapped in its biomass will be released -- adding, perhaps, to the enormous quantities of methane being untrapped in the arctic as the permafrost melts and vast, prehistoric peat bogs start to decay at an accelerated rate.

This, in turn, could accelerate the melting of the north polar ice cap, allowing darker water and rock to absorb more of the sunlight that snow and ice reflect back into space, warming the permafrost even more, releasing more methane, heating the earth even more, causing cause more tropical rain forests to dry up and/or burn, releasing more Co2.

We're talking, in other words, about a cascade effect, in which various natural processes all feed into each other in a series of massive positive feedback loops, quickly driving the global mean temperature higher -- much more quickly and far higher than most existing
ecosystems can tolerate or adapt to.

Whiskey Bar: And People Call Me a Pessimist

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