Synergy between population policy, climate adaptation and mitigation

Abstract

Global, national and regional population projections are embedded in projections of future greenhouse gas emissions and in the anticipated impacts of climate change on food and water security. However, few studies acknowledge population growth as a variable affecting outcomes. Neither the uncertainty around population projections nor the scope for interventions to moderate growth is discussed. Instead, a deterministic approach is taken, assuming that population growth is governed by economic and educational advances. This chapter reviews the treatment of population in climate change scenarios and the prospects for proactive interventions to influence outcomes. Sensitivity analyses have demonstrated population to be a dominant determinant of emissions. The assumption that population growth is determined by economic and educational settings is not well supported in historical evidence. Indeed, economic advance has rarely been sustained where fertility remained above three children per woman. In contrast, population-focused voluntary family planning programmes have achieved rapid fertility decline, even in very poor communities, and enabled more rapid economic advance. Policy-based projections of global population are presented, based on the historical course of nations that implemented effective voluntary family planning programmes. If remaining high-fertility nations adopted such programmes, global population could yet peak below 9 billion. Current trends make it more likely to exceed 13 billion people by 2100 unless regional population pressures cause catastrophic mortality rates from conflict and famine. Global support for family planning could reduce population by 15% by 2050 and 45% by 2100 compared with the current trend. Co-benefits include gender equity, child health and nutrition, economic advancement, environmental protection and conflict avoidance.