ISSN:
1573-1480
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract The dominant influence on global climate for the indefinite future is expected to be a warming in the middle and high latitudes of both hemispheres. The speed of the warming is uncertain. The warming in winter may exceed 1.0 degree per decade. The warming in summer is expected to be less. The cause is the accumulation of infra-red absorptive gases, especially CO2 and CH4, in the atmosphere. The sources are the combustion of fossil fuels, the destruction of forests and their soils, and, possibly, the warming itself, which can be expected to stimulate decay of organic matter in soils. The warming in these latitudes is expected to be accompanied by increased precipitation as climatic zones migrate generally poleward. A 1 °C change in mean temperature is equivalent to a change in latitude of 100–150 km. The changes expected are rapid enough to exceed the capacity of forests to migrate or otherwise adapt. Forest trees will die at their warmer and drier limits of distribution more rapidly than forests can be regenerated in regions where climates become favorable. The destruction of forests will add further to the releases of C to the atmosphere. There is no equivalent countervailing storage that has been identified. The result suggests that a significant enhancement of the warming beyond current predictions is to be expected. An open-ended, accelerating warming of the Earth at rates that bring rapid changes in climatic zones, drive forests to impoverishment, and raise sea level rapidly is beyond the limits of simple adjustments of the human enterprise. Steps to stabilize the atmospheric composition seem inevitable. Because the total emissions of C to the atmosphere are not known, the current rate of transfer from the atmosphere to the oceans is uncertain. But whatever the current total release to the atmosphere, the annual atmospheric increase is about 3.0 G-tons of C as CO2. At least three possibilities exist for reducing or eliminating the imbalance and moving toward long-term stability: (1) a reduction in the use of fossil fuels globally, now estimated as the source of about 5.6 G-tons of C annually; (2) a reduction or cessation of deforestation, now estimated as releasing 1–3 G-tons annually; (3) a vigorous program of reforestation that would remove from the atmosphere into storage in plants and soils about 1 G-ton of C annually for each 2 × 106 km2 tract reforested. Further adjustments in emissions will be appropriate as experience accumulates. Such steps are appropriate now and possible. They will bring widespread ancillary benefits to the human enterprise.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00138844
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