PROGRESS IN GEOGRAPHY ›› 2010, Vol. 29 ›› Issue (11): 1301-1310.doi: 10.11820/dlkxjz.2010.11.006

• Original Articles • Previous Articles     Next Articles

An Overview of Researches of Urbanization Effect on Land Surface Air Temperature Trends

REN Yuyu1, REN Guoyu1, ZHANG Aiying2   

  1. 1. Laboratory for Climate Studies, CMA, National Climate Center, Beijing 100081, China;
    2. Beijing Meteorological Science and Technology Service Center, Beijing 100089, China
  • Received:2009-11-01 Revised:2010-07-01 Online:2010-11-25 Published:2010-11-25

Abstract:

Urbanization may have affected the surface air temperature records at many stations in continents, especially in industrial regions like Europe, North America and East Asia. However, this issue is still under debate at present, especially at regional and global scales. Based on an overview of researches on urbanization effects on surface air temperature series mostly in the continents of northern Hemisphere, the nature and intensity of urbanization effects at different spatial scales are summarized and assessed. At city and local scales, most studies have found obvious urbanization effects, with big cities showing the most significant urban warming. At regional scale, the studies focused on mainland China and the United States also have showed significant urban warming in varied extents, in spite of the fact that a few studies have claimed an insignificant urban bias. It is obvious that the researches with robust methods to select reference stations have generally found significant urbanization effect on surface air temperature trends. For global or hemispheric average temperature series, researches are far from enough at present, but they have mostly indicated that the urbanization effect may be minor or insignificant, and it may have not exceeded 10% of the total warming observed. Studies have also found that the urbanization effect changes over time and regions. In East Asia, including China, Korea and Japan, urbanization has had very significant impact on surface temperature trend during the past half a century, but in Europe the significant urbanization effect might have occurred in the early 20th century and even the late 19th century. At present, there are still many problems and difficulties on the study of urbanization effect on temperature series, including the limited areas and time periods studied, radically different selection criteria of reference stations and imperfect methodology for urban bias adjustment. To solve these problems in the near future will help promote the progress of research.

Key words: China, climate change, Europe, surface air temperature, urban heat island, urbanization, USA