Do G7 and BRICS differ in growth–emission nexus? A multifractal and wavelet approach

This study examines the scale-dependent coupling between economic growth and CO2 emissions in the G7 and the BRICS, two major economic blocs and key emitters, by integrating multifractal detrended cross-correlation analysis (MF-DCCA) and wavelet coherence. We analyze annual per capita GDP and CO2 series from 1950 to 2022 to determine whether these countries exhibit distinct multiscale dependencies. MF-DCCA results show that most G7 economies exhibit nonlinear, intrinsic multifractality, while the BRICS countries display greater heterogeneity. India, China, and Brazil show clear signs of intrinsic multifractality, whereas Russia and South Africa exhibit no such evidence.Wavelet coherence further reveals that in the G7, economic growth typically leads CO2 emissions at business-cycle scales. Among the BRICS, Brazil, Russia, and China exhibit robust coherence at short- and mid-term scales, while India and South Africa remain weakly linked. An event–window comparison of the 1973 Oil Crisis and the 2008 Financial Crisis highlights the starkly contrasting responses of G7 and BRICS countries to these shocks. These findings enhance our understanding of multiscale growth–emission nexus and suggest that the G7 should adopt stable, long-term strategies while the BRICS require agile, scale-aware interventions to meet climate and sustainability challenges.