The Pyrocene by Stephen J. Pyne

Author:Stephen J. Pyne
Language: eng
Format: epub
ISBN: 9780520383586
Publisher: University of California Press

Pyric Transition: The Concept

The turning inside out of humanity’s relationship to fire deserves a name. Industrial combustion seems too bland, though no more so than aboriginal fire or agricultural fire. But the much-studied process of industrializing suggests an option for the moment of phase change, the kindling of this new fire as it were. Among the changes that the general transformations set in motion by industrializing is a “demographic transition” within the human populations experiencing it. Perhaps something similar occurs with the “population” of fires. In its original incarnation this was the expectation.

Human demographics combine two separate ratios or trends—the birth rate and the death rate. Initially upon industrializing, deaths decline but births continue. Then births decline, even below replacement value. For decades the overall population remains high because the old generations linger, but eventually the smaller new generations pull the cumulative numbers down. As countries begin industrializing, they suffer population explosions; in mature countries, populations decline. Something similar seems to happen with landscape fire.

As we should expect in a new form of fire colonization, the shock wave expresses itself in many ways that depend on the particulars of the firescapes it encounters. In humid forest lands it leads to an explosion of burning, as axe and fire strike lands opened by, and connected to global markets by, fossil fuel transportation, with abusive and often explosive burning the outcome. Fire’s presence blows up as old practices continue and new fuels and ignitions become available. Then, with decades of substitution and suppression, it diminishes, dropping below replacement value, or the ecological requirements for burning. In grasslands and arid lands, the process leads to the reverse. Burning implodes because those same arrangements encourage replanting to commercial crops, or overgrazing, or both, as former combustibles are replaced or fed to cattle and sheep. The effect is nearly instantaneous. Fire disappears from the land, perhaps returning only as woody vegetation or invasive exotics replace native grasses. Again, the needed population falls below ecological replacement value. To this extent the demographic transition serves as a heuristic concept.

The analogy can turn spongy, perhaps more metaphor than model. What exactly needs measuring? Is the population of fires the right metric? Or the area burned? Or is it the carbon throughput that combustion processes? The analogy falters, too, in that it is the death rate rather than the birth rate that declines. Traditional burning—second-fire in all its iterations—withers away; fire famines spread among many biotas. Meanwhile, the new burning—third-fire—continues exponentially. The Earth has more combustion than it can absorb. There are no internal checks and self-corrections comparable to the local, individual decisions to limit family size that shape human population.

The transition manifests itself locally on the land as people cease traditional burning, look for alternatives, and suppress fires of all kinds. The process passes across the Earth like the terminator. Its affects are first patchy, displayed by society, by nation, and by region. But with time it also globalizes through its impact on trade routes, on ideas and institutions, and on the atmosphere.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.