High spatio-temporal heterogeneity of carbon footprints in the Zhejiang Province, China, from 2005 to 2015: implications for climate change policies

Energy consumption is a major factor influencing climate change. Low-carbon strategies can be defined from carbon (C) footprint and ecological pressure caused by energy consumption. We hypothesized that this should be done at the regional and city levels because factors controlling C footprints vary with location and time, yet there is actually little knowledge at local levels. Here, we mapped the C emissions and footprint of 11 cities in the Zhejiang Province of China, a rapidly growing area of about 57 million inhabitants, which is representative of the strong economic growth in China. The C footprint is expressed as the land surface necessary to adsorb C emissions. We studied spatio-temporal evolution of C footprints from 2005 to 2015 using the center of gravity method. Results show that total annual C emissions due to energy consumption in Zhejiang increased by 40.83 million tons (55.8%) from 2005 to 2011. Then, from 2011 to 2015, C emissions decreased by 5.8%, which is explained by the 5-year national plan aiming at decreasing emissions. Similarly, the total C footprint increased by 55.8% from 29,201,904 hm² in 2005 to 45,496,817 hm² in 2011 and then declined by 5.8% from 2011 to 2015. At the city level, Ningbo has the largest C footprint contribution, whereas Lishui the lowest. Zhoushan shows an increase in C emissions and footprint, whereas Hangzhou and Shaoxing show a decline. The center of gravity of the C footprint is located in Shaoxing and is moving southeast from 2006 to 2011. Overall, our findings reveal the high spatial heterogeneity of C footprint at the regional and city levels, implying that national low-carbon strategies should be adapted at lower levels for higher efficiency.