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 1 Summary of the regression analysis of the simulated ΔCO₂/ΔCH₄ ratio at HAT using three sets of FFCO₂ emissions (A, B, and A + B) against three sets of emission ratios, FFCO₂/CH₄, (FFCO₂ + BioCO₂)/CH₄, and FFCO₂ in China

Emission ratio or emission	Set A (2000–2021)		Set B (2020–2021)		Set A + B		p value^c
Emission ratio or emission	Slope	Intercept^a	Slope	Intercept^a	Slope	Intercept^a	p value^c
FFCO₂/CH₄	1.10 ± 0.08	45 ± 5	1.07 ± 0.10	45 ± 7	1.08 ± 0.07	47 ± 4	0.63
(FFCO₂ + BioCO₂)/CH₄	1.19 ± 0.08	16 ± 7	1.07 ± 0.10	26 ± 9	1.12 ± 0.07	22 ± 6	0.51
FFCO₂	0.36 ± 0.02^b	58 ± 4	0.40 ± 0.04^b	46 ± 7	0.37 ± 0.02^b	56 ± 04	0.04

^aUnits of intercepts are given in mol mol⁻¹
^bUnits of slopes for FFCO₂ emission are given in (mol mol⁻¹)/TgC
^cp values are for the hypothesis that there is no significant difference between the slopes for the time-dependent fluxes and modified fluxes