Projected productivity losses and economic costs due to heat stress under climate change scenarios in Brazil – Nature

Report on Projected Productivity Losses and Economic Costs from Heat Stress in Brazil Under Climate Change Scenarios

Executive Summary

This report analyzes the projected impact of rising global temperatures on labor productivity and economic stability in Brazil throughout the 21st century. Utilizing two climate change scenarios (SSP2-4.5 and SSP5-8.5), the study evaluates productivity losses across key labor sectors—agriculture, civil construction, manufacturing, services, and informal labor. The findings indicate a severe threat to Brazil’s workforce, particularly in the North, Northeast, and Central-West regions, where daytime Wet Bulb Globe Temperature (WBGT) is projected to frequently exceed critical safety thresholds. Productivity in high-intensity outdoor sectors like agriculture could decline by over 90%. The associated economic costs are substantial, with daily losses potentially reaching USD 353 million under a high-emissions scenario. These impacts directly challenge the achievement of several Sustainable Development Goals (SDGs), including SDG 3 (Good Health and Well-being), SDG 8 (Decent Work and Economic Growth), and SDG 13 (Climate Action). The report underscores the urgent need for integrated policy responses that combine global climate mitigation with national adaptation strategies to protect workers, ensure economic resilience, and advance the 2030 Agenda for Sustainable Development.

1. Introduction: Climate Change and the Sustainable Development Agenda

The unprecedented rise in global temperatures poses a direct threat to human health and economic stability, undermining progress toward the Sustainable Development Goals. As global temperatures surpass the 1.5°C threshold outlined in the Paris Agreement, the frequency and intensity of extreme heat events escalate. This phenomenon has profound implications for labor, as heat stress diminishes the capacity for physical and cognitive work, a critical issue for achieving SDG 8 (Decent Work and Economic Growth). Workers in outdoor and physically demanding sectors are disproportionately affected, facing heightened health risks and income insecurity, which in turn jeopardizes SDG 3 (Good Health and Well-being) and SDG 1 (No Poverty). This study assesses these impacts in Brazil, a nation with significant climatic diversity and economic reliance on heat-exposed labor, providing critical data to inform policies aligned with SDG 13 (Climate Action) and SDG 10 (Reduced Inequalities).

2. Methodology

The analysis integrated climate modeling, population projections, and economic data to quantify the impacts of heat stress on Brazil’s workforce.

2.1. Climate Projections and Heat Stress Indicator

• Climate Scenarios: Data were analyzed under two Shared Socioeconomic Pathways (SSPs) from the Coupled Model Intercomparison Project (CMIP6):
  1. SSP2-4.5: An intermediate scenario with moderate mitigation efforts.
  2. SSP5-8.5: A high-emissions scenario driven by fossil-fuel development.
• Heat Stress Metric: The Wet Bulb Globe Temperature (WBGT) was calculated to provide a comprehensive measure of heat stress, incorporating air temperature, humidity, solar radiation, and wind speed. Projections were made for short-term (2025–2049), medium-term (2050–2074), and long-term (2075–2099) periods.

2.2. Labor and Economic Analysis

• Population Data: The study utilized projected population data consistent with the SSP scenarios to estimate the future workforce.
• Sectoral Analysis: The workforce was segmented into five key activities: agriculture, civil construction, manufacturing industry, services, and informal labor. The intensity of work was classified as moderate or high to estimate vulnerability to heat stress. This segmentation is crucial for understanding differentiated impacts on SDG 8.
• Productivity Loss Calculation: An established exposure-response function was used to estimate the fraction of working hours lost due to heat stress based on daily WBGT values.
• Economic Cost Estimation: The economic cost was derived by multiplying the productivity loss by the number of affected workers and their respective daily wages, providing a monetary valuation of the impact on economic growth.

3. Results and Analysis

3.1. Projected Increase in Heat Stress

The projections indicate a significant and progressive increase in heat stress across Brazil. Under the SSP5-8.5 scenario, daytime WBGT values in the North, Northeast, and Central-West regions are expected to frequently surpass 34°C, a critical threshold that severely compromises the safety of outdoor labor. This finding highlights a direct threat to SDG 3, as working under such conditions poses severe health risks.

3.2. Labor Productivity Losses

• Moderate-Intensity Activities (Manufacturing, Services): In the long term under the SSP5-8.5 scenario, productivity losses in these sectors are projected to exceed 90% in the Northern region.
• High-Intensity Activities (Agriculture, Construction, Informal Labor): These sectors face the most severe impacts. Productivity losses are projected to reach up to 95% in the long term, particularly affecting tropical and semi-arid zones. This drastic decline directly threatens food security and infrastructure development, impacting SDG 2 (Zero Hunger) and SDG 9 (Industry, Innovation and Infrastructure).

3.3. Economic Costs and Regional Inequalities

The economic consequences of productivity loss are substantial and vary significantly by region and climate scenario, underscoring the challenge to SDG 10 (Reduced Inequalities).

1. SSP2-4.5 Scenario (Intermediate Emissions): Total daily economic losses for regulated labor could reach USD 228 million by the end of the century.
2. SSP5-8.5 Scenario (High Emissions): Total daily losses could escalate to USD 353 million.
3. Informal Sector: This vulnerable group faces staggering potential losses, estimated at up to USD 160 million daily under the high-emissions scenario, exacerbating poverty and inequality in line with SDG 1 and SDG 10.
4. Regional Disparity: The Southeast and Northeast regions are projected to bear the highest absolute economic costs due to their large populations and economic activity. In contrast, the North faces the most extreme productivity loss percentages, threatening the livelihoods of communities dependent on agriculture and extractivism.

4. Discussion: Implications for Sustainable Development

4.1. Undermining Health, Decent Work, and Economic Growth (SDG 3 & 8)

The projected increase in extreme heat directly threatens the health and safety of millions of Brazilian workers. The lack of adequate protection, especially for the 39% of the workforce in the informal sector, creates conditions contrary to the principles of decent work. Reduced productivity translates into lower output and income, constraining economic growth and trapping vulnerable households in poverty.

4.2. Exacerbating Socioeconomic Inequalities (SDG 10)

Climate change acts as a risk multiplier for inequality. The study reveals that regions with historically lower levels of development and higher rates of informal labor (North and Northeast) will suffer the most severe productivity declines. This disparity threatens to widen the socioeconomic gap between regions and reinforces the need for targeted adaptation policies that prioritize the most vulnerable populations.

4.3. The Critical Need for Climate Action and Adaptation (SDG 13)

The stark difference in outcomes between the SSP2-4.5 and SSP5-8.5 scenarios provides clear evidence of the economic benefits of climate mitigation. Adhering to the goals of the Paris Agreement can avert the most catastrophic economic losses. Simultaneously, national adaptation strategies are essential to manage the unavoidable impacts of climate change. Such measures are not merely environmental policies but are fundamental to securing a sustainable economic future.

5. Conclusion and Recommendations

Climate-induced heat stress poses a formidable barrier to sustainable development in Brazil, with the potential to cripple key economic sectors, endanger worker health, and deepen regional inequalities. Without decisive action, the country faces a future of diminished productivity and significant economic loss, undermining decades of progress.

5.1. Policy Recommendations for Achieving the SDGs

To mitigate these risks and align with the 2030 Agenda, the following actions are recommended:

• Integrate Climate Adaptation into Labor Policy (SDG 8 & 13): Implement and enforce regulations that mandate protective measures for workers in heat-exposed environments, such as adjusted working hours, mandatory rest and hydration breaks, and access to cooling facilities.
• Strengthen Social Safety Nets (SDG 1 & 10): Develop social protection programs targeted at informal and seasonal workers who are most vulnerable to income loss from climate-related productivity declines.
• Promote Investment in Resilient Infrastructure (SDG 9 & 11): Encourage the adoption of technologies and work practices that reduce physical exertion and heat exposure, including mechanization in agriculture and the use of cooling materials in construction.
• Enhance Public Health Systems (SDG 3): Strengthen health surveillance systems to monitor and respond to heat-related illnesses among the working population and launch public awareness campaigns on the dangers of heat stress.
• Accelerate Climate Mitigation Efforts (SDG 13): Reinforce national commitments to reducing greenhouse gas emissions to contribute to global efforts to limit warming and thereby reduce the long-term severity of heat-related impacts.

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article highlights several interconnected issues that are directly relevant to the following Sustainable Development Goals (SDGs):

• SDG 3: Good Health and Well-being

  The article explicitly states that “Working under extreme heat conditions threatens health and well-being, which is aggravated by climate change.” It further discusses how increased exposure to extreme heat compromises physical activity and mental health, and raises the incidence of “heat exhaustion, sunstroke and other heat-related conditions.” This directly connects the core issue of heat stress to the goal of ensuring healthy lives and promoting well-being for all.

• SDG 8: Decent Work and Economic Growth

  This is a central theme of the article. The study focuses on estimating “the impact of an increase in global temperature on workability” and the resulting “productivity losses” and “economic costs.” It analyzes the effects on key labor sectors like agriculture, construction, and manufacturing. The article also discusses the precarious conditions of informal workers, who lack adequate protection, linking directly to the goal of promoting sustained, inclusive economic growth, full and productive employment, and decent work for all.

• SDG 10: Reduced Inequalities

  The analysis reveals significant regional disparities and socioeconomic inequalities. The article notes that “the North, Northeast and Central-West regions face significant increases in daytime WBGT” and that these regions, which have “high levels of informal labour,” will be the most impacted. It contrasts this with the milder impacts on the Southern region. This focus on how climate change disproportionately affects vulnerable regions and unprotected workers (like informal laborers) directly addresses the goal of reducing inequality within and among countries.

• SDG 13: Climate Action

  The entire study is framed within the context of climate change. It uses climate change scenarios (SSP2-4.5 and SSP5-8.5) to project future impacts and explicitly calls for “global mitigation action to curb the increase of global temperature” and the adoption of “national public policies that protect workers” as adaptation strategies. This aligns perfectly with the call to take urgent action to combat climate change and its impacts.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s detailed analysis, the following specific SDG targets can be identified:

1. Under SDG 3: Good Health and Well-being

   • Target 3.d: Strengthen the capacity of all countries, in particular developing countries, for early warning, risk reduction and management of national and global health risks.
     
     Explanation: The article’s analysis of projected heat stress and its health implications (heat exhaustion, sunstroke) serves as an early warning system. The call for policies like creating cool spaces, adjusting work hours, and ensuring hydration are measures for risk reduction and management of the health risks posed by extreme heat.

2. Under SDG 8: Decent Work and Economic Growth

   • Target 8.2: Achieve higher levels of economic productivity through diversification, technological upgrading and innovation…
     
     Explanation: The article quantifies how climate change leads to massive “productivity losses,” with projections that “productivity could fall by 90%” in some sectors. This directly relates to the challenge of maintaining and increasing economic productivity in the face of climate change. The discussion on investing in work environment technologies is also relevant here.
   • Target 8.8: Protect labour rights and promote safe and secure working environments for all workers, including migrant workers, in particular women migrants, and those in precarious employment.
     
     Explanation: The article highlights that extreme heat creates unsafe working conditions, especially for outdoor and informal workers who “face even more precarious conditions” and lack “adequate protection measures.” The study’s call for policies to protect workers directly supports the promotion of safe and secure work environments.

3. Under SDG 10: Reduced Inequalities

   • Target 10.2: By 2030, empower and promote the social, economic and political inclusion of all, irrespective of age, sex, disability, race, ethnicity, origin, religion or economic or other status.
     
     Explanation: The article points out that climate impacts “accentuating the social and economic inequalities,” with informal workers and those in poorer regions (North, Northeast) being more vulnerable. By identifying these disproportionately affected groups, the study underscores the need for inclusive policies that protect them from the economic and health shocks of climate change.

4. Under SDG 13: Climate Action

   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries.
     
     Explanation: The core of the article is about understanding the impacts of a climate-related hazard (extreme heat). The conclusion and discussion sections explicitly recommend adaptation strategies, such as “creating cool spaces, providing regular breaks, adjusting working hours and encouraging hydration,” which are essential for strengthening the resilience of the workforce and the economy.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

Yes, the article mentions and uses several specific indicators to measure the problems discussed, which can be used to track progress towards the identified targets.

• Wet Bulb Globe Temperature (WBGT)

  This is the primary scientific indicator used in the study to measure environmental heat stress. The article states it “combines air temperature, humidity, solar radiation, and wind speed to estimate the heat load imposed on the human body.” Tracking WBGT levels, especially the frequency of exceeding critical thresholds like 34°C, is a direct way to measure the climate-related health risk (relevant to Targets 3.d and 13.1).

• Productivity Loss (%)

  The study calculates and projects productivity loss as a percentage for different labor sectors. For example, it finds that in agriculture and construction, “productivity could fall by 90%.” This is a direct indicator of the impact on economic productivity and the effectiveness of safe work policies (relevant to Target 8.2 and 8.8).

• Economic Costs/Losses (in USD)

  The article quantifies the financial impact of reduced productivity, stating that “Daily economic losses for regulated labour activities could reach USD 228 million under SSP2-4.5 and up to USD 353 million in SSP5-8.5.” This monetary value is a powerful indicator for assessing the economic consequences of climate change and the benefits of mitigation and adaptation (relevant to Target 8.2).

• Working Hours Lost

  Although calculated for the globe, the article references that “extreme heat resulted in a record loss of 512 billion working hours” in 2023. This metric is implicitly used in the study’s methodology to calculate productivity loss and is a clear indicator of the impact on labor (relevant to Target 8.2).

• Regional and Sectoral Disparities in Economic Impact

  The article provides a breakdown of economic costs by region (e.g., Southeast vs. South) and by labor sector (formal vs. informal). These comparative figures serve as indicators of inequality, showing which populations are most vulnerable and bearing the heaviest burden (relevant to Target 10.2).

4. Create a table with three columns titled ‘SDGs, Targets and Indicators” to present the findings from analyzing the article. In this table, list the Sustainable Development Goals (SDGs), their corresponding targets, and the specific indicators identified in the article.

Source: nature.com