Direct Energy Consumption Associated Emissions by Rural-to-Urban Migrants in Beijing.

Hundreds of millions of rural residents have migrated to cities in China in recent years. Different lifestyles and living conditions lead to substantial changes in their household energy. Here, we present the result of a survey on direct household energy use of low-skilled rural-to-urban migrants in Beijing. The migrants moved up the energy ladder immediately after arriving in the city by replacing biomass fuels with coal, electricity, and liquefied petroleum gas. After the original shift, pattern of household energy use by the migrants has not changed much over decades, likely due to the long-existing household registration system (Hukou). As a result, the mix of energy types used by the rural-to-urban migrants were different from those by long-term urban residents, although total quantities were similar. Shifting from biomass fuels to coal, the migrants emitted 2.4 times more non-neutral CO2 than rural residents and 14% more than urban residents. The migration also resulted in significant increase in emissions of SO2 and mercury but dramatic decreases in some incomplete combustion products including particulate matter. All these changes have significant implication on air quality, health, and climate considering the scale of urbanization in China.