- Jul 19, 2012
- Reaction score
- Political Leaning
New paper finds temperature record in China contaminated by urban heat island effect in the Journal of Climate
It's apropos to point out that NASA has never examined the surface stations in the US or elsewhere to determine whether they're situated in proper sites and have not been affected by urbanization. A survey of the stations undertaken by an independent group in the US showed that close to 70% of them were improperly situated or were in places that had changed from rural to suburban or urban over time causing temperature measurements to be 2 to 3 degrees C too high. NASA has refused to acknowledge or correct for this.The impact of urbanization on temperature trends in China was investigated with emphasis on two aspects of urbanization, land cover change and human activity. A new station classification scheme was developed to incorporate these two aspects by utilizing land cover and energy consumption data. Observation temperature data of 274 stations and National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis temperature from 1979 to 2010 were used in conducting the observation minus reanalysis (OMR) method to detect urban influence. Results indicated that nearly half of the stations in the study area have been converted from non-urban to urban stations as a result of land cover change associated with urban expansion. We determined that both land cover change and human activity play important roles in temperature change and contribute to the observed warming, particularly in urbanized stations, where the highest amount of warming was detected. Urbanized stations showed higher OMR temperature trends than those of unchanged stations. In addition, a statistically significant positive relationship was detected between human activity and temperature trends, which suggests that the observed warming is closely related to the intensity and spatial extent of human activity. In fact, the urbanization effect is strongly affected by specific characteristics of urbanization in local and regional scales such as land cover change, human activity, and other related factors.