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annual growth rate for the most recent decade
(2000-09) was around 2 ppm. Beyond the enor-
mous, but as yet uncertain, climatic implications
for greenhouse warming, many other wetland
consequences result from mining and burning
fossil fuels.
10.3.2 Coal mining and acid rain
Coal mining historically was done mostly under-
ground in relatively small workings. However,
since the mid-twentieth century large open-pit
strip mines have become increasingly common
for economic and mine safety reasons. Early
strip mines were often simply abandoned after
removing the coal and left to overgrow with
brush and trees. Those areas are marked by
ridges of spoil and intervening troughs. As an
experiment, trees were planted on several thou-
sand hectares of mined land in southeastern
Kansas, United States in the late 1930s (Muilen-
burg 1961), and these sites are now wildlife
refuges known for excellent deer hunting and
i shing. However, acid water leaching from coal-
mine debris, known as gob piles, has degraded
downstream surface and ground water, and only
the most acid-tolerant organisms have survived
(Arruda 1992). Since 1969, Kansas state law
requires that mined land must be reclaimed for
productive agricultural use (Fig. 10-12). Mining
Figure 10-11.
Concrete plant associated with a large
coal strip mine in eastern Germany (see Fig. 8-24A).
Manufacturing concrete releases carbon dioxide from
two sources, i rst burning fossil fuel for thermal energy,
and second the conversion of carbonate rock into lime
and CO
2
. Photo by J.S. Aber.
Figure 10-12.
Big Brutus restored at the mining heritage visitors' center near West Mineral, Kansas, United States.
One of the world's two largest electric-power shovels, it stands 50 m tall with a working weight of 5000 metric tons.
Reclaimed mined land on right side. Blimp airphoto by J.S. Aber.
