Prediction on Changes of Permafrost in Northeastern China During the 21st Century Using the Combination of the Equivalent-Latitude and Finite Element Models

The global warming is word actuality and puzzle. The prediction on the changes of southern limit of permafrost in Northeastern China was achieved by combining of equivalent-latitude and finite element models. The mean annual soil surface temperature (MASST) has a close linear correlation with the MAAT, if the air temperature increment assumed to be 0.048degC/a for the studied period during the next 100 years. The results showed that: The warm permafrost would disappear after 50 or 100 years under global climate changing, especially near the southern limits of permafrost. The future mean annual ground temperatures (MAGTs) in different MASST zones would increase, with various extents and degrees. The permafrost table would deepen most remarkably in the zones where present MASST is around 0degC. The southern limits of Permafrost in Northeastern China accorded with 1.5degC MASST at present, and would continuously retreat to northward to the present MASST isotherms of 0.5degC and -0.5degC after 50 and 100 years. As a result, the area of permafrost would be reduced by 28.4% and 49.8% of that at present, respectively.