On the recently publicized list of ‘ten greatest events in 2005 national fundamental research,’ which was formulated after thorough assessment of academicians in Chinese Academy of Sciences (CAS) and Chinese Academy of Engineering Sciences, Chief Scientists of National 973 Projects, and heads of the national key laboratories, the Fourth Complex Scientific Expedition to Qomolangma (Mt. Everest) (FCSEQ) organized by the CAS comes the second among the ten. The following is a brief review of the expedition.

In an effort to further understand the traditionally regarded purely natural environmental background in the northern slope of Qomolangma, this large-scale expedition themed with the ‘responses of Qomolangma regions to global change’ and last over three months from March 10 to June 10, 2005.

More than 50 scientific research staff from ten units including ITPCAS, IGSNRR, CAREERI, IGGCAS, EERC，Peking University, Sichuan University and Tibet University participated in the expedition. Therein, they conducted research in atmospheric physics, atmospheric chemistry, glaciers and the hydrology, ecology and the environment, and the evolution of the height of Qomolangma. The crew reached as high as 7200m.a.s.l to collect samples ranging from air, river/lake water, ice and snow, rock, aerosols, plants, human hair, etc numbering nearly 2000. These samples are distributed between 1600 to 7200m of elevation on Qomolangma, and covered an area of over 40,000km². At the present stage, they are under laboratory analysis for chemical and micro-biological properties. Besides, the crew also managed to set up four auto-meteorological monitoring systems respectively at 4300, 5200, 5800, and 6500m.a.s.l along the northern slope. Thus research staff can closely monitor field data to facilitate future field work and environmental research of this region.

Additionally, the expedition crew also made some primary discoveries. The discovery of such alpine plant species never recorded of existence in Ronbuk Valley as cedar is one. Comparison of remote sensing data also reports of serious vegetation degradation in the core area within Qomolangma natural reserve, in particular, the startling appearance of poor cold and alpine vegetation, alpine meadow and bush degradation. Scientists also find increasing melting of glaciers in northern slope of Qomolangma. Take the Ronbuk glacier, whose melting area has formed numerous lakes already. Such situation might spread to the upper reach of the glacier, posing potential effect on the utilization of water resources in the lower reaches.

On top of all these, a breakthrough has been achieved by the State Bureau of Surveying and Mapping, who measured anew the height of Qomolangma. The number of 8844.43m will thereupon be acknowledged worldwide, supplanting the former one.