Forests support global crop supply through atmospheric moisture transport – Nature

Report on the Role of Forests in Global Crop Supply and Sustainable Development

Executive Summary

This report analyzes the critical role of forests in sustaining global agriculture, directly impacting the achievement of the Sustainable Development Goals (SDGs). Anomalous precipitation patterns, exacerbated by climate change, pose a significant threat to achieving SDG 2 (Zero Hunger) by destabilizing global crop supplies. This analysis reveals that forests function as a crucial nature-based solution, regulating atmospheric moisture and buffering agricultural systems against climate-induced water stress. Key findings indicate that moisture from forests supports 18% of global crop production and 30% of crop exports, highlighting a direct link between forest health (SDG 15: Life on Land) and global food security (SDG 2). The analysis further uncovers complex national and transboundary dependencies through atmospheric moisture flows, underscoring the necessity for enhanced international cooperation (SDG 17: Partnerships for the Goals) to manage these shared resources and build climate-resilient food systems (SDG 13: Climate Action).

Introduction: Interlinking Climate, Water, Food, and Ecosystems for the SDGs

The Challenge to SDG 2: Zero Hunger

Global food systems face unprecedented challenges from climate change. Increased frequency and intensity of climate extremes are causing more erratic precipitation patterns, which directly threaten agricultural productivity and the stability of global food supplies. This volatility undermines progress towards SDG 2 (Zero Hunger), which aims to end hunger, achieve food security, improve nutrition, and promote sustainable agriculture. More than half of all crop production losses are attributed to climate extremes, with droughts capable of causing up to a 10% reduction in output, jeopardizing food security for millions.

Forests as a Nature-Based Solution for SDG 13 and SDG 15

Forests, as major sources of atmospheric moisture through processes like evapotranspiration, can buffer downwind regions against precipitation anomalies, particularly during droughts and heatwaves. This ecosystem service is vital for climate adaptation and contributes directly to SDG 13 (Climate Action). The strategic conservation and restoration of forests, a core target of SDG 15 (Life on Land), is therefore not only crucial for protecting biodiversity and sequestering carbon but also for regulating the planetary water cycle (SDG 6: Clean Water and Sanitation) and sustaining the agricultural productivity upon which humanity depends.

Analysis of Forest-Derived Moisture and its Contribution to Agriculture

Global Moisture Flows and Agricultural Reliance

The study identifies significant atmospheric moisture transport from forested areas to key agricultural regions worldwide. Major crop-producing nations, including Brazil, Argentina, Canada, Russia, and China, exhibit high dependence on precipitation originating from forests. This moisture is critical for fulfilling crop water requirements, supporting both green water (rainfed) and blue water (irrigated) agricultural systems. This connection demonstrates how the sustainable management of terrestrial ecosystems under SDG 15 directly supports the water-related targets of SDG 6 and the food security goals of SDG 2.

Contribution to Global Crop Supply

Globally, moisture originating from forests is estimated to support:

• 18% of the total crop production studied.
• 30% of the total crop export studied.

This quantitative link demonstrates that achieving the conservation targets of SDG 15 is instrumental for securing the global food supply chain and meeting the objectives of SDG 2.

National and Transboundary Dependencies

The report identifies two primary modes of dependency on forest-derived moisture, highlighting the need for tailored governance approaches:

1. Nationally Recycled Moisture: 105 countries depend on forests within their own borders. Nations with large tropical forests like Brazil, Indonesia, and the Democratic Republic of Congo are prominent examples, where national forest policy directly impacts domestic food production and economic stability.
2. Transboundary Moisture: 155 countries depend on forests located in other nations. This creates a shared vulnerability and underscores the need for collaborative governance under SDG 17. For instance, Argentina’s agricultural sector receives approximately 14% of its annual precipitation from transboundary sources, mainly forests in Brazil.

Global Connectivity, Systemic Risk, and the Need for Partnerships (SDG 17)

Typologies of Interdependence: Circular and Cascading Flows

The intersection of atmospheric moisture flows and international crop trade creates complex interdependencies that expose the global food system to systemic risks. These can be categorized as follows:

• Circular Flows: A bilateral dependency where a forested nation provides moisture to a crop-exporting nation and, in turn, imports crops from it. The relationship between Brazil (moisture supplier) and its neighbors like Paraguay and Argentina (crop suppliers) exemplifies this mutual reliance, creating opportunities for cooperative agreements that benefit both food security and ecosystem preservation.
• Cascading Flows: A multilateral dependency where a crop-importing nation is indirectly reliant on forests in a third country that provides moisture to its primary crop supplier. This exposes importers to remote environmental risks, such as deforestation or forest fires, which can cascade through the international trade network and disrupt food supplies far from the source.

Implications for International Cooperation

The existence of these flows means that deforestation in one country can negatively impact agricultural yields and economic stability in another, potentially thousands of kilometers away. For example, crop importers in Europe, Asia, and Africa are indirectly dependent on the health of South American forests. Similarly, disruptions to Russian forests could impact crop production in Ukraine and Kazakhstan, with cascading effects on food-importing nations in the Middle East and Africa. This interconnectedness makes international cooperation, as called for in SDG 17 (Partnerships for the Goals), essential for managing shared risks.

Conclusions and Policy Recommendations for Achieving the SDGs

Leveraging Forest Conservation for Multiple SDGs

The findings provide a compelling, evidence-based case for integrating forest conservation (SDG 15) into national and international strategies for food security (SDG 2) and climate adaptation (SDG 13). Protecting upwind forests should be recognized as a critical investment in agricultural resilience and a cost-effective, nature-based solution for mitigating climate-induced risks to the global food supply. This approach aligns with and reinforces existing global commitments, including the Glasgow Leaders’ Declaration on Forests and Land Use and the Kunming-Montreal Global Biodiversity Framework.

Advancing Global Governance for Atmospheric Moisture

The transboundary nature of atmospheric moisture flows necessitates the development of novel governance mechanisms built on international cooperation, a central tenet of SDG 17. Recognizing atmospheric moisture as a shared global commons is a critical first step toward managing the interconnected risks to water, food, and ecosystem security. Bilateral and regional agreements, particularly in identified hotspot regions like South America and Eurasia, could pioneer such governance frameworks, ensuring that the management of forests contributes to a sustainable and equitable future for all.

Analysis of Sustainable Development Goals (SDGs) in the Article

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

The article addresses several interconnected Sustainable Development Goals (SDGs) by exploring the relationship between forests, climate, agriculture, and global trade. The primary SDGs identified are:

• SDG 2: Zero Hunger

  This goal is central to the article, which investigates how “anomalous precipitation patterns associated with climate change increasingly threaten global crop supply.” The study directly links the health of forest ecosystems to agricultural productivity and the stability of the global food system, aiming to ensure a “productive agricultural system that can fulfil society’s demand for food.”

• SDG 13: Climate Action

  The article frames its entire analysis within the context of climate change. It highlights that “global precipitation patterns are likely to become more erratic as climate extremes and variability have increased in frequency and intensity.” By proposing forest conservation as a strategy to “buffer these risks” and stabilize moisture supply, the article addresses the need for climate adaptation and resilience in the agricultural sector.

• SDG 15: Life on Land

  This goal is directly addressed through the article’s focus on the role of forests. The study argues for the strategic conservation of forests (“strategically conserving forests located upwind of agricultural areas could be leveraged to safeguard global crop supply”). It quantifies the ecosystem service of moisture provision by forests and discusses the negative impacts of deforestation on downwind precipitation and agriculture, thereby emphasizing the importance of sustainable forest management.

• SDG 17: Partnerships for the Goals

  The article highlights the transboundary nature of atmospheric moisture flows and crop trade, revealing complex interdependencies between countries. It identifies “circular and cascading flows” where crop-importing nations indirectly depend on forests in other countries. This underscores the need for international cooperation and governance mechanisms to manage shared resources like atmospheric moisture, as seen in the discussion of “bilateral cooperation” between countries like Brazil and its neighbors.

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

Based on the issues discussed, the following specific SDG targets are relevant:

1. Under SDG 2 (Zero Hunger):

   • Target 2.4: By 2030, ensure sustainable food production systems and implement resilient agricultural practices that increase productivity and production, that help maintain ecosystems, that strengthen capacity for adaptation to climate change, extreme weather, drought, flooding and other disasters and that progressively improve land and soil quality.
     
     Explanation: The article directly supports this target by investigating how forest conservation can create more resilient agricultural systems by stabilizing precipitation, which is crucial for adapting to climate change and extreme weather events like droughts.

2. 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 study’s core proposal—using forest conservation to “buffer” against anomalous precipitation and “mitigating the escalating climate-induced risks threatening agriculture”—is a direct strategy for strengthening the resilience of the global food supply chain to climate hazards.

3. Under SDG 15 (Life on Land):

   • Target 15.1: By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements.
     
     Explanation: The article provides a strong scientific case for forest conservation by quantifying their role as a “major moisture source” for agriculture, thus highlighting a critical ecosystem service that needs to be maintained.
   • Target 15.2: By 2020, promote the implementation of sustainable management of all types of forests, halt deforestation, restore degraded forests and substantially increase afforestation and reforestation globally.
     
     Explanation: The article implicitly advocates for this target by detailing how deforestation “leads to lower precipitation on downwind agriculture” and reduces agricultural revenue, thereby providing an economic and food security-based argument to halt deforestation.

4. Under SDG 17 (Partnerships for the Goals):

   • Target 17.14: Enhance policy coherence for sustainable development.
     
     Explanation: The article reveals how policies on forestry in one country can impact agricultural outcomes and food security in another. The analysis of “circular and cascading connectivity between countries” demonstrates the need for coherent policies across sectors (agriculture, environment, trade) and borders to ensure a stable global crop supply.

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

The article mentions or implies several quantitative indicators that can be used to measure progress:

• Crop Production and Export Volume: The study frequently uses “crop production (Cprod in Mtonnes yr−1)” and “crop export (Cexp in Mtonnes yr−1)” to quantify the output of agricultural systems. These can serve as indicators for Target 2.4 by measuring agricultural productivity.
• Crop Production Loss: The article mentions that “drought can cause up to 10% crop production loss.” Measuring the reduction in crop losses due to climate extremes would be a direct indicator of increased resilience, relevant to Target 13.1.
• Percentage of Precipitation from Forests: A key metric developed in the study is the amount of moisture agricultural areas receive from forests, expressed as a percentage of annual precipitation (e.g., “agricultural areas in 155 countries rely on transboundary forests for up to 40% of annual precipitation”). This can act as an indicator for the ecosystem services provided by forests under Target 15.1.
• Forest Cover and Deforestation Rate: Although not presented as a primary result, the concept of forest cover is fundamental to the analysis. The article discusses how a “percentage point of forest loss in the Amazon” leads to a “0.25% decrease in annual precipitation.” Forest cover area and its rate of change (deforestation) are direct indicators for Target 15.2.
• Transboundary Moisture and Crop Flows: The study quantifies “nationally recycled moisture flow” and “transboundary moisture flow.” These metrics, especially when analyzed as “circular and cascading flows,” serve as indicators of international interdependence and can be used to assess the need for and effectiveness of policy coherence and partnerships under Target 17.14.

4. Table of SDGs, Targets, and Indicators

Source: nature.com