Q&A: The role of soil health in food security and tackling climate change – Carbon Brief

Report on the State of Global Soil Health and its Alignment with Sustainable Development Goals

The capacity to feed a global population of 8.2 billion is fundamentally dependent on the health of the world’s soils. This report outlines the current state of soil degradation, its causes, and potential solutions, with a significant emphasis on its direct implications for achieving the United Nations Sustainable Development Goals (SDGs).

1. Current Status of Global Soil Degradation

Scientific assessments indicate a severe decline in global soil health, a critical issue for sustainable development. This degradation directly threatens the achievement of several SDGs, most notably SDG 2 (Zero Hunger), SDG 13 (Climate Action), and SDG 15 (Life on Land).

• Over one-third of the world’s agricultural land is now classified as degraded.
• Since the dawn of agriculture, the world’s soils have lost an estimated 133 billion tonnes of carbon, impacting their fertility and capacity to mitigate climate change, a core component of SDG 13.
• This loss of soil health jeopardizes global food security, undermining progress towards SDG 2.
• A significant knowledge gap exists regarding the state of soils, particularly in developing nations, hindering targeted interventions and monitoring for SDG 15.3 (Land Degradation Neutrality).

The Drivers and Impacts of Soil Degradation on Sustainable Development

Modern industrial agriculture, while increasing yields, has introduced practices that contribute significantly to soil degradation. These practices are contrary to the principles of sustainable production outlined in SDG 12 (Responsible Consumption and Production).

2.1. Primary Causes of Degradation

1. Industrial Farming Practices: Monocropping, excessive tillage, and the use of heavy machinery compact soil and reduce biodiversity.
2. Chemical Inputs: Over-reliance on synthetic fertilizers and pesticides disrupts the natural microbial ecosystems essential for soil life.
3. Land Use Change: Deforestation and overgrazing remove protective vegetation, leading to erosion and loss of organic matter.

2.2. Types of Soil Degradation

• Physical Degradation: Includes compaction and erosion, which reduce water infiltration and root growth.
• Chemical Degradation: Involves nutrient depletion, salinization, and contamination from agrochemicals.
• Biological Degradation: Refers to the loss of soil organic matter and biodiversity, which are crucial for nutrient cycling and soil structure.

The lack of comprehensive soil data in the Global South represents a major obstacle to achieving SDG 15, as it prevents accurate assessment and management of land resources. This information deficit is a social and political challenge that impedes sustainable land management.

The Imperative of Soil Health for Food Security, Climate Action, and Well-being

Healthy soils are a cornerstone for achieving multiple interconnected SDGs. Their degradation has far-reaching consequences for human and planetary health.

3.1. Food Security and Nutrition (SDG 2 & SDG 3)

Approximately 95% of global food is produced on soil, making its health a prerequisite for achieving SDG 2 (Zero Hunger). Soil degradation has already reduced food production by an estimated 13% to 23%. Projections indicate that continued degradation could cut global food production by another 12% in the next 25 years. Furthermore, nutrient-deficient soils lead to nutrient-deficient crops, contributing to malnutrition and impacting SDG 3 (Good Health and Well-being).

3.2. Climate Change Mitigation (SDG 13)

Soils are a critical carbon reservoir, and their management is integral to SDG 13 (Climate Action). Agricultural soils have the potential to sequester up to 4% of global greenhouse gas emissions annually. Practices that enhance soil carbon sequestration can make a significant contribution to meeting the objectives of the Paris Agreement. However, the permanence and scale of this sequestration potential remain subjects of scientific debate, highlighting the need for robust monitoring and verification.

Strategies for Soil Regeneration and Sustainable Management

Reversing soil degradation requires a transition to regenerative practices and the adoption of innovative technologies, aligning with SDG 9 (Industry, Innovation and Infrastructure) and SDG 12 (Responsible Consumption and Production).

4.1. Regenerative Agricultural Practices

Regenerative agriculture aims to restore soil health by mimicking natural ecological processes. Key practices include:

• Reduced Tillage: Minimizing soil disturbance to protect soil structure and microbial life.
• Crop Rotation and Cover Cropping: Diversifying plant life to enhance soil organic matter and nutrient cycling.
• Integrated Systems: Combining crop and livestock systems to create closed-loop nutrient cycles.
• Organic Inputs: Applying manure and compost to replenish organic matter and improve soil fertility.

These practices have been shown to increase soil carbon, enhance biodiversity, and improve farm profitability, contributing to SDG 1 (No Poverty) and SDG 8 (Decent Work and Economic Growth) for farming communities.

4.2. Carbon Dioxide Removal (CDR) Technologies

Emerging technologies offer additional pathways for enhancing soil carbon, directly supporting SDG 13.

• Biochar: A carbon-rich material produced from organic matter that improves soil fertility, water retention, and long-term carbon storage.
• Enhanced Rock Weathering: The application of crushed silicate rocks to agricultural lands to capture atmospheric CO2 and store it as stable carbonate minerals.

While promising, these techniques require further research to address challenges related to cost, scalability, and potential environmental side effects.

International Policy and the Centrality of Soil Health in the SDG Framework

Soil health is increasingly recognized within international policy frameworks as essential for sustainable development. This recognition is crucial for mobilizing action and financing in line with SDG 17 (Partnerships for the Goals).

5.1. Soil Health in the Sustainable Development Goals

Soil is explicitly and implicitly linked to numerous SDG targets, most prominently:

• Target 15.3: “By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world.”
• Target 2.4: Ensure sustainable food production systems and implement resilient agricultural practices that…help maintain ecosystems…and progressively improve land and soil quality.

5.2. Role of International Conventions

The three Rio Conventions provide platforms for advancing soil health on the global agenda:

1. UN Convention to Combat Desertification (UNCCD): Leads efforts on Land Degradation Neutrality (LDN), with over 100 countries setting national targets.
2. UN Framework Convention on Climate Change (UNFCCC): The Emirates Declaration from COP28 committed 160 nations to integrate agriculture and food systems, including soil health, into their climate action plans.
3. UN Convention on Biological Diversity (UN CBD): The Kunming-Montreal Global Biodiversity Framework includes targets for sustainable agriculture and ecosystem restoration, both of which depend on healthy soils.

Translating these high-level commitments into effective, on-the-ground action requires integrated policy, adequate financing, and the co-creation of solutions with farmers, Indigenous peoples, and other local stakeholders to achieve the 2030 Agenda for Sustainable Development.

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

The article on soil health directly addresses and connects to several Sustainable Development Goals (SDGs) due to the fundamental role of soil in food production, environmental stability, and climate regulation. The primary SDGs identified are:

• SDG 2: Zero Hunger

  This goal is central to the article’s theme. The text explicitly states that “Feeding the 8.2 billion people who inhabit the planet depends on healthy soils” and that “around 95% of the food the world consumes is produced, directly or indirectly, on soil”. The discussion on soil degradation reducing food production by 13% to 23% and the potential for regenerative agriculture to improve yields and farmer profits directly relates to ensuring food security and promoting sustainable agriculture.

• SDG 13: Climate Action

  The article extensively discusses the link between soil health and climate change. It highlights that industrial agriculture is “responsible for 22% of global greenhouse gas emissions” and that healthy soils play a crucial role in climate mitigation. The text notes that “Agricultural soils could sequester up to 4% of global greenhouse gas emissions annually” and explores techniques like biochar and enhanced rock weathering for CO2 removal, directly connecting to actions to combat climate change and its impacts.

• SDG 15: Life on Land

  This is the most explicitly mentioned SDG in the article. The core issue discussed is soil degradation, which is a key component of land degradation. The article states that “more than one-third of the world’s agricultural land now described by scientists as ‘degraded'”. It directly references SDG Target 15.3, which calls on countries to “restore degraded land and soil” and “strive to achieve a land-degradation neutral world”. The focus on desertification, biodiversity loss due to poor agricultural practices, and the restoration of terrestrial ecosystems places the article firmly within the scope of SDG 15.

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

Based on the detailed discussion in the article, several specific targets under the identified SDGs can be pinpointed:

1. Target 2.4 (under SDG 2)

   “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’s extensive coverage of regenerative agriculture, including practices like no-till farming, crop rotation, and mixed farming systems, directly aligns with this target. These practices are presented as solutions to improve soil health, maintain ecosystems (by restoring soil biodiversity), and create resilient food systems that can produce stable yields even under stress conditions like drought.

2. Target 13.2 (under SDG 13)

   “Integrate climate change measures into national policies, strategies and planning.”

   Explanation: The article mentions the “Emirates Declaration on Sustainable Agriculture, Resilient Food Systems and Climate Action” from COP28, where 160 countries committed to “integrating agriculture and food systems into their nationally determined contributions, national adaptation plans and national biodiversity strategies and action plans (NBSAPs)”. This is a direct example of integrating climate measures related to land use and agriculture into national policies, as called for by this target.

3. Target 15.3 (under SDG 15)

   “By 2030, combat desertification, restore degraded land and soil, including land affected by desertification, drought and floods, and strive to achieve a land degradation-neutral world.”

   Explanation: The article explicitly names this target, stating that soil health and regeneration feature in it. The entire article is a deep dive into the causes of soil degradation and the methods for its restoration. It also mentions that under the UNCCD, more than 100 countries have set land degradation neutrality (LDN) targets, which is the core objective of Target 15.3.

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 implies several quantitative and qualitative indicators that can be used to measure progress towards the identified targets.

• Indicators for Target 2.4 (Sustainable Food Production):

  • Crop Yields and Farmer Profitability: The article cites studies comparing conventional and regenerative agriculture, noting that regenerative systems for maize had “29% lower grain production, but 78% higher profits”. This provides a direct economic and productivity indicator.
  • Soil Health Metrics: The text mentions several measurable indicators of soil health used by farmers and researchers, including “root depth,” “earthworm abundance,” “microbial biomass,” and “soil organic carbon.” A 2022 study found that diversified farming systems led to a “62% increase in soil microbial biomass and a 157% increase in soil carbon.”

• Indicators for Target 13.2 (Climate Policy Integration):

  • Integration into National Climate Plans: The primary indicator is the number of countries that have integrated agriculture and food systems into their Nationally Determined Contributions (NDCs) and National Adaptation Plans, as committed to in the Emirates Declaration mentioned in the article.
  • Carbon Sequestration Potential: The article provides a figure that “Agricultural soils could sequester up to 4% of global greenhouse gas emissions annually,” which can serve as a benchmark for measuring the contribution of soil health initiatives to national climate goals.

• Indicators for Target 15.3 (Land Degradation Neutrality):

  • Proportion of Degraded Land: This is the official indicator for Target 15.3. The article provides several data points that can be used for measurement and comparison, such as “more than one-third of the world’s agricultural land now described by scientists as ‘degraded’,” “about 35% of the world’s agricultural land…is degraded,” and specific figures for the EU (61%) and the UK (40%).

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: carbonbrief.org