BEIJING - 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.