Tibet plateau as clean as North Pole: report
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E-mail Xinhua, November 18, 2015
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An aerial view of the Tibet plateau [File photo/Xinhua] |
Several data revealed by a global research endeavor showed that the Tibetan plateau remains one of the world's cleanest regions despite pollutants discharged by surrounding regions.
"The environment background value of pollutants in the Tibetan plateau, which is similar to that of the Arctic, is remarkably lower than that of densely-populated areas," said an environment change evaluation report organized by the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences (CAS).
Pollutants in the air of the plateau, such as black carbon and heavy metal, have increased by two times since the 1950s, the report said.
Citing lake and ice core records, the report said South Asia and Central Asia are the two major contributors to the plateau's black carbon, a climate forcing agent which heats atmosphere and warms the Earth.
The average deposition of black carbon in southeastern and central parts of the plateau from the beginning of this century was three times the average in the period between the 1950s and the 1980s.
"Black carbon on the plateau is now at its highest level in nearly 100 years, which is lower than that in the Alps in France and similar to the Arctic," the report said.
Though the level of heavy metal recorded in ice and lake cores of the plateau is higher than or similar to the south and north pole regions, it is much lower than that in densely-populated areas.
In addition, persistent organic pollutants (POPs) in the air remain at a relatively low level, which is close to or lower than that in the Arctic region or the Alps.
The plateau's disaster risks increase as climate is warming and human activities are increasing.
If humans continue to exert a positive influence on environment and improve disaster early warning capability, the low environment background value as one of the world's cleanest areas could be maintained, the report said.
The CAS institute describes the Tibetan plateau in its report as the areas mainly in southwest China's Tibet Autonomous Region, with an average altitude of over 4,500 meters.
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Natural disasters active on Tibetan plateau
Natural disasters are on the rise on the Tibetan plateau as the region is affected by global warming and increased human activity, according to a recent environmental assessment report.
The report on environmental change of the world's highest plateau was published Wednesday by the Institute of Tibetan Plateau Research under the Chinese Academy of Sciences.
It said disasters including landslides, torrential floods and snow disasters are expected to increase and fires will be more difficult to prevent and extinguish.
According to the report, about 1,500 mountain torrents were reported on the plateau from 1950 to 2010, with the worst in 1998 when more than 50 counties in the Tibet autonomous region were affected.
The floods on the plateau are attributed to frequent extreme precipitation during rainy seasons.
Meanwhile, the report warned iced lakes and barrier lakes on the plateau are also posing a threat as more than 20 overflowed during the 20th century, leading to severe disasters in the region.
As one of the major forests in the nation, risk of fire is also high due to strong wind and lack of rain and snow, it said.
From 1988 to 2014, a total of 373 forest fires were reported, according to the report.
In addition, the scale of snow storms and avalanches has expanded markedly over the past 40 years under the influence of climate change, affecting human activities and the climate in the north hemisphere, the report said.
With an average altitude of over 4,500 meters, the Tibetan plateau, known as the core of "The Third Pole," refers to the areas within Southwest China's Tibet autonomous region.
Majority of Tibetan plateau permafrost may disappear by 2100
About 81 percent of the permafrost on the Tibetan plateau will possibly disappear around 2100 due to the warming climate, a Chinese scientific report said Wednesday.
The permafrost is estimated to be reduced by 39 percent in the near future if the temperature continues to rise, said the report issued by the Institute of Tibetan Plateau Research under Chinese Academy of Sciences, quoting a model analysis result.
The utmost temperature of the frozen earth is rising at a rate of about 0.3 degrees Celsius every decade, the report said. A 1.1-degree rise of average temperature on the plateau will have little impact on the permafrost, but if such a rise reaches 2.91 degrees, the majority of the permafrost will disappear, it said.
Human activities also contribute to the shrink of frozen soil. Activity of frozen earth layers can be monitored as deep as 4.57 meters along the imposing Qinghai-Tibet railway stretching across the plateau, the report said. The figure is up to 1.37 meters deeper than those with no human influence and is still growing as much as 7.5 centimeters every year, the report said.
More than half the plateau is covered in permafrost, with large reserves of carbon dioxide trapped within the ice.
The plateau has also shown an increasing desertification, mainly around the source region of the Yangtze River, where the desert area has reached33,200 square kilometers, or 66 percent of the total deserted land around all headwaters of China.
The contraction of frozen earth and the expanded desertification demonstrate deterioration of the land-surface environment on the Tibetan plateau, according to the report.
However, it added soil erosion has been generally curbed after 40 years of treatment.
Eco environment along Qinghai-Tibet Railway restoring
The ecological environment along the Qinghai-Tibet Railway, the world's highest railway, is recovering after its first five years of operation, said a report issued by a Chinese national research institute on Wednesday.
"Parts of the areas are in a state which is close to or even better than the natural state of its surrounding regions," said an environment change evaluation report on the Tibetan plateau, organized by the Institute of Tibetan Plateau Research of the Chinese Academy of Sciences (CAS).
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