Cites generate about 70% of global greenhouse gas emissions. Therefore Cities have large advantages in implementing greenhouse gas (GHG) reduction actions economically, socially, and polically. The production and consumption activities of cities can extend to the heart of upstream and downstream customers. By producing and processing basic materials such as imported energy, food, water, and construction materials, final products are consumed by local and nonlocal consumers. At present it lacks complete characterization to urban system in view of the city scale of carbon emissions and carbon footprint research. Thereby, evaluation and comparison of low carbon cities and emission reduction strategy analysis is not accurate and thorough. Urban ecological process and the controlling research group(Shenghui Cui’ research team), Institute of Urban Environment, Chinese Academy of Sciences, established complete evaluation model, make quantitative to carbon emission, the emissions embodied in import (EEI) and emissions embodied in export (EEE) within the city boundary with the combination of bottom-up and top-down method, define four kinds of footprints and four measurement indicators of low-carbon city according to different policy relevances and preliminary summarize the common features of urban carbon footprint. Eight typical rapidly developing and actively trading cities(such as Beijing, Xiamen, etc) in China were selecting as study cases. The results showed that: (1) By comparing the four accounting of carbon footprint (CF) boundary, most of EEI come from imported energy, steel, cement and other primary products of the other mainland China (MC) developing or underdeveloped region, and most of the EEE footprint was flowing to the city carbon-intensive products and functions services the in regions of MC, principal North American and Europe,etc. (2) Evaluation of degree of low-carbon city need to integrate four indicators of the carbon production intensity(CPI), the carbon consumption level (CCL) the balance of import and export and balance of trade intensity of the cities. (3) Construction was the largest consumer of carbon, consuming embodied carbon from the electrical, non-metallic materials and primary metal departments of cities. (4) The CPI of upstream producers will ultimately affect CPI of the urban final products and CCL of urban residents, improve the production level of China and other developing countries, reduce the carbon intensity of principal basic raw materials and then improve the production efficiency of the city in the perspective of life cycle. The established methods in this study can well copy to other input-output compiled table of research of urban carbon footprint and provide contrast standard for features of urban basic carbon footprint in the process of urbanization. Related research results were published in international journals of the field of environmental science, Environmental Research Letters and Environmental Science & Technology. This study was supported by the National Natural Science Foundation of China (71003090 and 71273252), the National Key Technology R&D Program of the Ministry of Science and Technology (2012BAC21B03), China Scholarship Council (201404910215) and the US National Science Foundation PIRE Program. The full text links below: http://dx.doi.org/10.1088/1748-9326/10/5/054001； http://pubs.acs.org/doi/abs/10.1021/acs.est.6b00985。

Composition and boundaries of various components and methods for calculating the urban carbon footprint.

Development patterns of eight Chinese cities from the perspectives of carbon production efficiency and consumption levels.

Composition of the construction sector’s consumed carbon footprint Note: 1. The gridded bars were the largest carbon inflow sectors (Mt CO 2e); 2. The percentage after each city was the share in PBF (%)