Near-real-time estimation of fossil fuel CO2 emissions from China based on atmospheric observations on Hateruma and Yonaguni Islands, Japan

Progress in Earth and Planetary Science

Table 2 Observed ΔCO₂/ΔCH₄ ratio and estimated change in the FFCO₂/CH₄ emission ratio in China from the preceding 9-year average

Date (year/month)	Monthly ΔCO₂/ΔCH₄ (mol mol⁻¹)		Estimated change in the FFCO₂/CH₄ emission ratio from the preceding 9 years (%)
Date (year/month)	HAT	YON	HAT	YON	Weighted Ave
2020/01	147 ± 2	145 ± 1	18 ± 10	14 ± 15	17 ± 8
2020/02	100 ± 2	97 ± 2	− 35 ± 9	− 36 ± 10	− 36 ± 7
2020/03	117 ± 2	126 ± 2	− 18 ± 11	− 5 ± 13	− 12 ± 8
2021/01	146 ± 2	149 ± 1	18 ± 10	19 ± 15	18 ± 8
2021/02	126 ± 2	126 ± 1	− 4 ± 13	1 ± 15	− 2 ± 10
2021/03	147 ± 2	170 ± 2	16 ± 16	48 ± 20	29 ± 12
2022/01	146 ± 2	156 ± 1	18 ± 10	27 ± 16	20 ± 9
2022/02	126 ± 3	124 ± 1	− 4 ± 13	− 2 ± 14	− 3 ± 10
2022/03	117 ± 2	132 ± 2	− 19 ± 11	2 ± 13	− 10 ± 9
2011–2019/01	131 ± 7	133 ± 11	–	–	–
2011–2019/02	129 ± 11	126 ± 12	–	–	–
2011–2019/03	133 ± 11	130 ± 11	–	–	–