6
OUR PLANET MAGAZINE
CLIMATE CHANGE AND THE CRYOSPHERE
Climate change is not just an environmental concern, but also a major
development issue. The magnitude of the major climate and environmental
changes related to global warming over the past century has gone beyond
the range of natural variability and now poses a major threat to the survival of
humankind and sustainable social and economic development. It has become
an imminent challenge to everyone in the world.
It has also had severe impacts on China's climate and environment and has
brought challenges to its development. A proper response to climate change
is thus part and parcel of national efforts for achieving harmony between
men and nature and for building a harmonious society.
The latest findings in the Intergovernmental Panel on Climate Change's
Working Group I contribution to its Fourth Assessment Report show a marked
increase in global average surface temperature, continuous sea level rise and
steady shrinking of snow cover in most areas of the Northern Hemisphere --
all of which indicate a trend of global warming. From 1906 to 2005 the mean
global surface temperature increased by 0.74°C (within a range of 0.56°C to
0.92°C). The average temperatures in the northern hemisphere during the
second half of the 20th century were very likely higher than during any 50
year period in the last 500 years, and likely the highest in at least the past
1,300 years.
In the context of global warming, the climate and environment in China have
also undergone significant and profound changes. China, like other parts of
the globe, will witness a continuous rise in temperature in the future. There
will also be changes in the pattern of precipitation.
Over the recent 100 years, China's annual average surface temperature has
increased significantly by about 0.5°C to 0.8°C. 2006 had the highest annual
average temperature across the country since 1951, and the average winter
temperature was the second highest in the same period, after 1998.
Projections of future climate change suggest that China's surface temperature
is likely to increase noticeably under different emission scenarios over the
next twenty to a hundred years. Precipitation also shows an increasing
trend, though this varies remarkably in both time and space. Northern
China will witness more days with precipitation, while there will more heavy
rain in the south of the country. Some areas may suffer more excessively
heavy precipitation.
Over the past five decades China has also experienced a dramatic change in
both the frequency and the intensity of extreme weather and climate events,
which are increasing in both number and strength. In 2006, it registered a good
number of record extreme weather events, such as: the high temperature and
drought scorching Chongqing and Sichuan; Typhoon "Saomai", the strongest
since 1951, hitting Zhejiang Province; severe drought plaguing northern
China; and a fallout of 330,000 tons of dust on Beijing in just one night. Climate
warming also brings a higher forest fire risk in dry and arid regions, and last
year accounted for the most severe ones in northeast China since 1987.
China's daily maximum and minimum temperatures will rise in future. The
number of extremely cold days is likely to fall, but the hot summer period is
likely to get longer, and extreme high temperatures, heat waves and droughts
will occur more frequently.
Climate change increases the volatility of agricultural production and losses
of crops and livestock caused by meteorological disasters. Failure to take
adaptation measures might reduce China's total crop production by 510 per
cent by 2030 in general. Wheat, rice and corn would be particularly affected.
It is also leading to an increasingly serious shortage of water resources in
China. The measured runoff of the top six rivers since the 1950s suggests a
decline. In northern China some rivers experienced drying up and some
areas are suffering a drastic drop in groundwater. In the future there would
be a further imbalance between water supply and demand, particularly in
dry years and in north and northwest China. Climate change could have a
heavy impact on major projects, posing increasingly higher risks to their safe
operation. It may, for example, increase precipitation in the upper reaches of
the Yangtze River basin, likely leading to such geological disasters as mud-rock
flows and landslides in the Three Gorges Reservoir catchment. The expected
warmer temperature of the Qinghai-Tibet Plateau might further degenerate
the permafrost along its railway, likely destabilizing segments of the rail link.
The impacts of climate change on China's natural and ecological systems--
and on its economy and society--are also reflected in a number of other
facets. such as the shrinking acreage of lakes, falling water levels, reduced
wetland, degraded grassland, expanding desertification, damaged
biodiversity, and degraded marine ecosystems, including mangroves and
coral reefs. Climate change is posing a grim and real threat to China's economy
and its society, a threat that is likely to continue, turning from bad to worse.
The Chinese government attaches great importance to climate protection
and has taken various measures to address this issue. In a period prone to
contingent, extreme and protracted catastrophes, prevention and mitigation
are becoming more imperative. It is necessary to actively respond to it, and
to combat extreme climate disasters, with a robust emergency response
system and an improved climatic, ecological and environmental protection,
to enable due contributions to be made towards implementing the "Scientific
Development Concept", towards creating a harmonious society, towards
better and faster economic development and towards sustainable socio-
economic development in China.
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climate change and development