The current international climate policy framework is mainly based on the national and regional level of macroscopic carbon emissions data, such as the regional per capita carbon emissions are often used as the indicator to measure the fairness of carbon emission rights.

However, the per capita emissions based on regional macro data can not accurately reveal the low carbon emissions of the poor within the region, and cover up the emission differences among people intra-country and intra-region, the household carbon emission data based on field surveys could compensate for this deficiency well.

The research group for Regional Carbon Emission and Reduction Quotas from Scientific Information Center for Resources and Environment/Lanzhou Branch of the National Science Library, Chinese Academy of Sciences undertaked the family interview surveys from the summer of 2011 to the spring of 2012, selecting 1523 urban and rural families in 24 cities and counties of Gansu, Xinjiang, Ningxia, Inner Mongolia, Shanxi, Shaanxi, Qinghai in Northwestern China, in order to reveal the pattern of household carbon emissions in Northwestern China.

The research paper Household Carbon Emission Differences and their Driving Factors in Northwestern China has been published on Chinese Science Bulletin, 2013, No.3.

Family is the basic unit of social system. Household carbon emission is one of the important sources of the anthropogenic greenhouse gas which is closely related with the family income and household consumption Surveying and assessing the household carbon emissions from the basic family activities, which includes the direct carbon emissions generating from fossil fuel and the indirect carbon emissions caused by household consumption expenditure, could more accurately quantitative analysis the contribution of household activities and find their differences among different regions and families.

The study established an evaluation index of Household Carbon Emission. Based on a >1 year's survey of the main domestic energy consumption and consumption expenditure data of urban and rural households in Northwestern China, the group discovered the status of household carbon emissions in Northwestern China.

The results showed the household carbon emission per capita in Northwestern China was only 2.05 tons CO2 per year. The direct carbon emissions generating from fossil fuel usage accounted for 39.29%, and the indirect carbon emissions caused by household consumption expenditure on electricity and other activities comprised 60.71%.

Household carbon emission was mainly from coal, electricity and food consumption, which accounted for 62.85% which is necessary for the natural human demands, followed by carbon emission generated by oil, education, culture, entertainment and clothing consumption, and carbon emission caused by water and LPG consumption was at the least, only accounting for 1.20% (Figure1). Carbon emissions varied between urban and rural households, as well as between households in different provinces.

Household carbon emission was mainly affected by geographic environment, family size and income, and household age structure. Family size had the most prominent effect on the per capita household carbon emission, the bigger the family size, the lower the per capita household carbon emission (Figure2).

The fact, that the household carbon emission in Northwestern China is at a relatively low level, has important reference value for the international discussion on the carbon reduction responsibility which has great influence on the poverty population's rights, and will be helpful for the development of the regional energy-saving emission reduction targets.

This study was supported by the "Strategic Priority Research Program - Climate Change: Carbon Budget and Related Issues" of the Chinese Academy of Sciences,Grant No. XDA05140100 QU J S, ZHANG Z Q, ZENG J J, et al. Household carbon emission differences and their driving factors in Northwestern China (in Chinese). Chinese Science Bulletin, 2013, 58(3): 260-266.