Mean summer temperature in Eastern China has increased by 082 °C since the 1950s and five of the hottest summers have occurred since 2000 This study estimates anthropogenic influence to have caused a greater than 60-fold increase in the likelihood of extreme summer heat and projects that hot summers will continue to increase in frequency

Rapid increase in the risk of extreme summer heat in Eastern China

The contribution of urbanization to warming in China has been difficult to quantify owing to the proximity of rural stations to urban areas. A novel detection and attribution analysis separates the contribution of all external forcings, and shows that urbanization accounts for about one-third (0.5 °C) of the total warming signal in China (1.4 °C).

Contribution of urbanization to warming in China

Land-use/land cover change (LUCC) is one of the fundamental causes of global environmental change. In recent years, understanding the regional climate impact of LUCC has become a hot-discussed topic worldwide. Some studies have explored LUCC impact on regional climate in specific cities, provinces, or farming areas. However, the quick-urbanized areas, which are highly influenced by human activities, have the most severe land-use changes in developing countries, and their climatic impact cannot be ignored. This study aims to identify the impact of land-use change coupled with urbanization on regional temperature and precipitation in the metropolitan areas of middle and lower reaches of the Yangtze River in China by means of spatial analysis and numeric methods. Based on the exploration of land-use change and climate change during 1988–2008, the impact of land-use transition from non-built-up area to built-up area on temperature and precipitation was analyzed. The results indicated that the land-use conversion has affected the regional temperature with an increasing effect in the study area, while the influence on precipitation was not so significant. The results can provide useful information for spatial planning policies in consideration of regional climate change.

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Impact of Urbanization and Land-Use Change on Surface Climate in Middle and Lower Reaches of the Yangtze River, 1988–2008

Observed changes in surface air temperature and precipitation in the Hindu Kush Himalayan region over the last 100-plus years

China has experienced an unprecedented urbanization and industrialization in the past decades. In this research, we examined the dynamics of construction lands and impervious surface areas (ISA) based on land use/cover change and ISA datasets between 2000 and 2008, which were provided by the national resources and environmental remote sensing information platform. The results indicated that the construction areas and ISA increased by 3468.30 and 2212.24 km 2 /a in this period primarily due to the implementation of national macro-development strategies and fast-growing economy. In 2008, ISA accounted for 0.86% of the total land area in China. Urban land areas increased by 43.46% between 2000 and 2008. The annual growth rate of 1788.22 km 2 /a in this period was 2.18 times that in the 1990s. In particular, urban ISA increased by 53.30% between 2000 and 2008 with an annual growth rate of 1348.85 km 2 /a. During the 8 years, the ISA in China increased rapidly, especially in the Beijing-Tianjin-Tangshan Metropolitan Region, Pearl River Delta, Yangtze River Delta, and the western China region. The increasing ISA may influence potentially water environmental quality in the major basins. In particular, the number of subbasins having ISA of greater than 10% increased considerably, which were primarily distributed in the Haihe River, Yangtze River and Pearl River basins. In 2008, 14.42% of the basin areas were affected by the increased ISA.

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Spatiotemporal dynamics of impervious surface areas across China during the early 21st century

Since the 1980s, China has undergone rapid urbanization. Meanwhile, the climate has been warming substantially. In this paper, the urbanization effect on observed temperatures from 1980 to 2009 in China is estimated, based on analysis of urban land use from satellite observation. Urban land-use expansion (ΔU) during 1980–2005 is applied as an urbanization index. According to these ΔU values, stations are divided into three categories: (C1) intense urbanization around the stations; (C2) moderate urbanization around the stations; and (C3) minimal urbanization around the stations. Most C1 stations are in municipalities or provincial capitals, while C2 stations tend to be in prefecture-level cities. C3 stations are mostly in counties. The urban heat island (UHI) effect can be estimated if the urban effect on C3 is negligible. The warming of C1 or C2 relative to that of C3 represents their urbanization effects, assuming that the same larger-scale natural warming has affected each category. For C1, the local urbanization effect is 0.258°C/10 a over 1980–2009, accounting for 41% of the total warming; the trend at C2 is 0.099°C/10 a, or 21%. For all China, the urbanization effect is 0.09°C/10a, accounting for 20% of the total national warming. Winter urban warming is greater than in summer. The assumption of negligible urbanization effect on C3 is debatable, and so the true urbanization effect may equal or slightly exceed estimates. Further, the ΔU index may have some uncertainties, for it is only one of the urbanization indices. However, it provides a new and direct estimation of environmental change, in contrast to indirect indices.

Fang

Papers

Estimation of urbanization bias in observed surface temperature change in China from 1980 to 2009 using satellite land-use data