The moderating role of renewable energy in the linkage of air quality and healthcare expenditure in Africa. Fresh perspectives through the method of moments quantile regression

Africa is highly vulnerable not just to the negative economic and social perspectives attributable to climate change but also healthcare. Using data on 47 countries (2000–2021), the study explores the distributional heterogenous impact of poor air quality (carbon dioxide- $${CO}_{2}$$ , methane- $${CH}_{4}$$ and nitrous oxide- $${N}_{2}O$$ ) on government healthcare expenditure (GHCE) spectrum (10th–90th) using the novel method of moments quantile regression (MMQR) technique for the first time in the African context. Different from previous studies, the moderating role of renewable energy consumption (REC) is analysed. Finding reveals that $${CO}_{2}$$ and $${CH}_{4}$$ emissions negatively influence GHCE at (50th-90th) quantiles, while $${N}_{2}O$$ emissions increase GHCE in (10th-70th) quantiles, reflecting pollutant-specific fiscal burdens. The interactive terms are negative and significant across all quantiles with varying impact levels; uniform in $${CH}_{4}$$ model, gradual progression in the $${CO}_{2}$$ model and steep in the $${N}_{2}O$$ model. Overall, the moderation role of REC cut across both economic and pollutant type perspectives, functioning as both a health and fiscal stabilizer. GDP/capita, trade openness and reductions in infant mortality consistently boost GHCE, while ICT exerts a substitutional effect, indicating dynamic shift towards digital healthcare. By way of policy implication to attaining Sustainable Development Goals 3,7 and 13 from the African perspective, the study suggests the expansion of renewable energy use for the dual role of environmental sustainability and a structural tool for sustainable healthcare financing, a robust public healthcare system and the wellbeing of the citizenry.