Global trade-offs between consumption, carbon prices and equity

As the remaining carbon budget continues to dwindle, economic growth strains efforts to limit global warming to 1.5 °C. Reducing unnecessary production and consumption in high-income regions and among the wealthy, and organising production more around human needs and human well-being, may alleviate pressures on technology-driven decarbonisation strategies. We employ a modified integrated assessment model to explore the interaction between converging per-capita consumption, climate policy stringency and equity. Our pathways demonstrate that lower-consumption futures are associated with substantially lower warming, 0.3-1.1 °C across different carbon price trajectories, relative to high-consumption futures. Comparatively, global convergence of incomes between regions has a small influence on global temperature outcomes (<±0.1 °C). These findings indicate that reducing high per-capita consumption in high-income regions is a primary lever for achieving futures with equitable and decent living standards while meeting global climate targets. While such transformations may face political challenges, our scenarios suggest that unconstrained growth futures make it considerably harder to remain within safe climate limits.