Combined top-down and bottom-up approach for CO2 emissions estimation in building sector of beijing: Taking new energy vehicles into consideration

Abstract

The current top-down method for calculating carbon emissions in the building sector erroneously includes carbon emissions from charging new energy vehicles (NEVs). This error is particularly concerning as the number of NEVs is expected to rise significantly in the future, thereby exacerbating the negative impact on the formulation of effective carbon reduction policies. This study analyzes carbon emissions in Beijing's building sector from 2011 to 2020 and estimates NEV-related indirect emissions from 2015 to 2020. Findings show that electricity consumption is the primary energy source in Beijing's building sector, increasing electricity-related carbon emissions from 63.36 % to 67.18 % of the total. Additionally, the indirect carbon emissions from NEVs have exhibited a steady increase from 208,800 tons in 2015 to 1.18 million tons in 2020, with their contribution to the overall carbon emissions from buildings escalating from 0.27 % to 1.44 %. Intriguingly, the study uncovers that private new energy cars do not significantly differ from conventional private fuel passenger cars in terms of their indirect carbon emissions. The findings of this study are expected to inform the development of accurate carbon emission estimation strategies in Beijing's building sector and facilitate the formulation of effective policies in the future.