No Robust Evidence for a GDP–Methane Relationship in Africa, 1970–2024: A Multi-Specification Test Against the Environmental Kuznets Curve and STIRPAT Frameworks

Afeez Olabisi Yusuf , Kofoworola Funmilayo Odutayo, Ahmed Olaniyi Yusuf, Peter Adedayo Oladetuyi

The green growth hypothesis, that economic growth can be decoupled from environmental harm, is embedded in the Sustainable Development Goals and national climate strategies, yet remains contested, with recent evidence questioning whether decoupling occurs fast enough to meet climate targets. Methane policy for Africa, including the Global Methane Pledge's 22-plus African signatories, implicitly assumes some relationship between economic development and emissions trajectories, following the Environmental Kuznets Curve (EKC) or STIRPAT/IPAT traditions. Two prior studies, each on six-country African subsamples, reported a positive GDP-methane relationship and EKC-consistent nonlinearity. We test both frameworks on a substantially larger, more representative sample: a 53-country, 1970–2024 panel (2,765 country-years) combining EDGAR CH4 emissions with World Bank population and GDP data, analyzed via two-way fixed-effects regression with cluster-robust standard errors under four complementary specifications, a non-parametric shape check, and a formal test of parameter stability across an independently-identified 1995 structural break. Population was strongly associated with CH4 (elasticity approximately 1.06, p<0.001); GDP was not significant once population was controlled for (p=0.082). A nominally significant inverted-U pattern (p=0.025) was supported by only 1.2% of observations from 3 of 53 countries, and lost significance (p=0.068) when those countries were excluded. The canonical per-capita EKC specification showed no nonlinearity at all (p=0.452), confirmed non-parametrically, and a formal interaction test found no evidence either coefficient differed before versus after 1995. Across every specification and robustness axis tested, no credible evidence supports a growth-driven methane trajectory in Africa. This provides a region- and gas-specific data point in the broader empirical debate over whether growth-compatible environmental transformation is occurring, and indicates that methane mitigation policy should rest on sector-specific interventions rather than assumptions about economic development pathways.