CHINA’S WILD WEST - Wildlife Conservation in China: Preserving the Habitat of China's Wild West - page 33

English and promulgated on Web sites 32 as claiming that the temperature increase had
been documented as 0.336°C per year rather than per decade (an easy mistake to make
because the raw data must be expressed in terms of “annual temperature changes per
decade,” but nonetheless, off by a factor of ten).
Second, some publications provide data, assert a drying trend, but never bother to
link their conclusion to the data via statistical analysis. A scholarly attempt to exam-
ine underlying causes of the “desertification disaster” in southern Qinghai presented
decadal mean temperatures and precipitation amounts (categorized by seasons) for
southern Qinghai from 1961 through 1999 and concluded that these data demonstrated
a “clear warming and drying trend” attributable to global warming. 33 But the authors
never bothered to test whether these negative trends, so obvious to their eyes, were
statistically significant. Of their four seasonal precipitation “trends” (in addition to
the annual, grand mean), only one (winter) was even close to achieving the usual 0.05
level of statistical significance, and that trend was positive, not negative, as would be
the case had there been a drying trend. 34
Third, some publications accurately cite reliable evidence of warming or drying, but
then use this data to make inappropriate inferences about other geographic locations, or
interpret the data on the wrong time-scale. In northeastern China, for example, data suggest
that precipitation may indeed have decreased over the past half-century, but China is a big
and diverse country and what occurs in northeastern China does not necessarily apply to
the west. 35 There is also little doubt that western China has experienced a gradual drying
trend when measured over the past 30,000 years; it may also be drier now than during the
Han Dynasty, when written Chinese records began to include the area. Climate change
on such a recent geologic scale is supported by palynological work and studies of relict
vegetation structure. 36 It is not surprising that the source of most of Asia's great rivers once
accumulated more moisture than the semi-desert we find there today. But some writing
conflates this slow, natural drying (associated with the continuing uplift of the Himalayas,
one of the world's youngest mountain ranges) with a much more rapid deterioration in
ground water supplies, river flows, and grassland conditions. It seems unlikely that when
Kazak and Tibetan pastoralists despair of current grassland conditions or speak of higher
precipitation in “earlier days” that they are referring to the late Pleistocene.
This confusion of time-scales is clearly evident in the disagreement over the causes of
the decline of Qinghai Lake, China's largest inland lake. While admitting that the lake
has been drying up and that the rate of contraction is faster now than in the past, most
Chinese official statements continue to blame “natural factors” for the majority of the
problem. 37 To bolster this claim, reference is sometimes made to the fact that, early dur-
ing the Holocene, Qinghai Lake was much larger than its current size; various records
support the notion that it began retreating well before settlers began siphoning off water
from its sources for agriculture in the twentieth century. Most sources agree that the lake
level has been declining at a rate of roughly 0.1m/year since the 1950s, 38 thus exposing
hundreds of square kilometers of previously inundated lands. But if this rate of decline
is no faster than the ancient, postglacial rate, Qinghai Lake would have been at its largest
known extent as recently as the year 1125 C . E ., and during the middle of the Han Dynasty
would have been at an impossibly high level of almost 3,400 m, well higher than it is