What interannual variability of CO2 in East Asia can tell us about effectiveness of carbon reduction policies? A pilot study using CarbonTracker-Asia, emission inventories and satellite observations

Abstract

Evaluation of carbon reduction policies in East Asia is essential since 30-35% carbon dioxide emissions are originated from this region. We estimate interannual differences (ID) of CO2 concentration from CarbonTracker-Asia and ID of CO2 emissions from ODIAC inventories to find the footprints of carbon reduction policies in East Asia. We show that among national policies introduced in East Asia, 12th Five Year Plan of China (12th FYP) has most remarkable footprint in CO2 emission trends. In China CO2 emissions are decreased on ~140% in the period of 12th FYP (2011-2015) comparing to prior 2005-2010 period. The deployment of carbon reduction plans in other East Asian countries resulted in weaker decrease (20-50%) in CO2 emissions at national level during the same period. Despite recent negative emission trend, CO2 concentration ID in East Asia is positive. In 2005-2015 period, CO2 concentration ID in East Asia varies from -44 to 14%, shows no connection to any carbon reduction policy and exhibits long-term increase of CO2 with compound annual growth of 0.56% in average. As a result of such growth, by 2020 median mixing ratio of CO2 will increase up to 412.6 ppm with peaks in the provinces of Eastern China. Our results suggest that emission inventories can help to understand whether national carbon policy is practically implemented or just theoretically initialized. CarbonTracker-Asia can help to understand how spatial patterns of CO2 concentration may change in short-time thus highlighting the regions where carbon reduction policies should be potentially implemented.