【世界银行】不作为的代价：量化气候变化对中低收入国家健康的影响-2024

The Cost of Inaction: Quantifying the Impact of Climate Change on Health in Low- and Middle-Income Countries

Core Content

This report, The Cost of Inaction: Quantifying the Impact of Climate Change on Health in Low- and Middle-Income Countries, is a World Bank publication that assesses the health and economic impacts of climate change in low- and middle-income countries (LMICs). It emphasizes the urgency of addressing climate change as a health emergency and advocates for a comprehensive, systems-based approach to climate and health adaptation and mitigation.

Main Findings

1. Health Impacts of Climate Change

• Climate change is already having significant effects on human health, including increased frequency of extreme weather events, the spread of infectious diseases, and disruptions to food systems.
• These impacts are expected to worsen over time, with a growing number of cases and deaths from climate-sensitive health risks.
• The geographical range of these diseases is also projected to expand, affecting more regions.
• LMICs are particularly vulnerable due to higher poverty levels, income inequality, and weaker health systems.

2. Economic Cost of Inaction

• The economic cost of inaction on climate-related health impacts is substantial.
• By 2050, the economic cost could reach USD 8.6–15.4 trillion under SSP3 and USD 11.0–20.8 trillion under SSP2.
• These costs represent 0.7%–1.3% of GDP in LMICs.
• Sub-Saharan Africa (SSA) and South Asia (SA) are expected to bear the majority of the burden, with SSA alone accounting for 71% of cases and nearly half of all deaths from climate-related health impacts between 2026 and 2050.
• The economic cost for SSA is projected to be 2.7%–3.6% of GDP by 2050, which is significantly higher than for other regions.

3. Climate Scenarios Used

• The report uses two socioeconomic development scenarios from the IPCC Sixth Assessment Report (AR6): SSP2 (SSP2-4.5) and SSP3 (SSP3-7.0).
• These scenarios represent middle-of-the-road development paths between the worst-case RCP8.5 and increasingly unlikely best-case RCP2.6 and RCP1.9.
• SSP3 assumes high population growth, limited economic development, and reduced investments in health and education.
• SSP2 assumes moderate growth in population and economy with slow progress toward Sustainable Development Goals (SDGs).

4. Underestimation of Real Impacts

• The health impacts analyzed are limited to specific diseases (extreme heat, waterborne diseases like diarrhea, vector-borne diseases like dengue and malaria, and stunting).
• The report does not include other health risks such as non-communicable diseases and mental health.
• The geographical spread of these diseases is also not fully captured due to the use of a static model.
• As a result, the reported impacts are likely underestimates of the true scale of climate change's effect on health in LMICs.

Key Views and Policy Implications

• Climate change is a global health crisis, and its effects will intensify in the coming decades.
• Health systems in LMICs are especially vulnerable and require urgent investment to build resilience against climate-related health risks.
• The World Bank aims to expand climate and health investments to help LMICs develop climate-resilient, low-carbon health systems.
• The report does not advocate for a vertical approach to specific diseases but instead promotes a health systems approach to address broader climate health impacts.
• Global collaboration and transformative action are necessary to mitigate the human and economic costs of climate change.

Key Information

• The report is based on 69 LMICs, representing 96.2% of the total population of all LMICs.
• The baseline year is 2020, and the analysis covers short-term (2026–2030), medium-term (2026–2050), and long-term (2026–2100) projections.
• The economic cost of inaction is expected to be much higher than previously estimated, as the report does not cover all health risks.
• The World Bank has already invested a third of its total health financing in climate-related projects, but more is needed to meet its 2030 goal of providing quality health services to 1.5 billion people.
• The report highlights the need for tailored solutions and global partnerships to support climate and health adaptation efforts.

Conclusion

• Climate change poses a severe threat to global health, particularly in LMICs, where the burden will be disproportionate.
• The economic cost of inaction is astronomical, with trillions of dollars at risk in the coming decades.
• The report calls for immediate, bold action to reduce greenhouse gas emissions and strengthen health systems.
• It emphasizes a systems-based approach over narrow disease-specific interventions.
• Global collaboration and adequate funding are essential to address the climate and health crisis effectively.