Post-Mining Landscapes as Natural Carbon Sinks: Potential for Ecological Restoration ^†

Abstract

In the coming decades, mineral extraction will cease at several locations in the Czech Republic. This article examines the transformation of these sites into natural carbon storage reservoirs after mining has ceased. This innovative approach supports sustainable land use, helps mitigate climate change, and restores ecological landscape functions.

1. Introduction

In the context of the increasing impacts of climate change and the commitments arising from the Paris Agreement, the European Union has committed to achieving climate neutrality by 2050. This ambitious goal requires not only significant reductions in greenhouse gas emissions across all economic sectors but also an enhancement of both natural and technological carbon sinks. One of the key tools in this regard is carbon management based on CO₂ sequestration in natural reservoirs, particularly in the land use, forestry, and agriculture sectors (known as LULUCF—Land Use, Land Use Change and Forestry).

European legislation reflects this trend through several key regulations, among which the amended Regulation (EU) 2018/841 stands out. This regulation sets targets for carbon sequestration by 2030, and the newly adopted Regulation (EU) 2023/839 establishes a framework for the voluntary certification of natural carbon storage. The aim of these measures is the systematic strengthening of carbon sinks, both through nature-based approaches (e.g., agroforestry, peatland restoration) and technological solutions (e.g., BECCS).

Current developments suggest that carbon sequestration certification, which is currently voluntary, could in the future be integrated into the EU Emissions Trading System (EU ETS). This development presents not only an environmental challenge but also a potential economic opportunity for both the private and public sectors, while simultaneously placing new demands on the transparency, auditability, and long-term sustainability of carbon measures.

This article aims to summarize the development of European legislation in the field of carbon dioxide sequestration, analyze its key elements, and discuss potential future directions, including impacts on landowners, forest managers, and land managers with a focus on reclaimed areas following mining activities. From the experiences gained in studying the dynamics of CO₂ sequestration on anthropogenic and reclaimed soils, there is a high potential for utilizing post-mining landscapes for these purposes.

2. European Legislation in the Fields of Emission Reduction and CO₂ Sequestration

Climate change and commitments arising from international agreements, particularly the Paris Agreement, have prompted the European Union to adopt an extensive legislative framework focused on reducing greenhouse gas emissions and enhancing natural carbon sinks. Carbon dioxide sequestration through soils, vegetation, and other natural reservoirs is gradually becoming an equally important tool for direct emissions reduction and is therefore reflected in key European regulations and strategic documents. This chapter summarizes the main legislative frameworks that define the direction of European climate policy in the areas of land use, forestry, and carbon management, and outlines future developments, including the potential expansion of the Emissions Trading System (EU ETS) to include the LULUCF sector. Special attention is given to how these legislative tools create opportunities for the active involvement of landowners and managers of reclaimed areas in climate-oriented management.

2.1. Regulation (EU) 2018/841 of the European Parliament and of the Council

The land use and forestry sector (known as LULUCF) represents a significant potential for achieving the climate goals set by the European Union and the Paris Agreement, particularly in the context of reducing carbon dioxide emissions. The application of sustainable management practices in this sector can contribute to mitigating climate change in several ways, primarily through increasing and maintaining carbon stocks and enhancing the landscape’s ability to absorb carbon. Sustainable forest and land management allows for the long-term preservation of the productivity, regenerative capacity, and vitality of these ecosystems, thereby supporting the economic and social development of regions while simultaneously reducing the carbon footprint of the LULUCF sector.

The proposed regulation builds on the existing regulation of the European Parliament and Council (EU) No. 529/2013 regarding the accounting of greenhouse gas emissions and removals from land use, land-use change, and forestry activities. During the period 2021–2030, this framework will be updated and expanded to ensure that the land use and forestry sector does not result in net CO₂ emissions, but instead contributes to achieving the long-term goal of increasing overall carbon sequestration in the EU territory.

The regulation further declares that there is no direct obligation for private entities to account for or report greenhouse gas emissions or removals. Instead, it establishes a monitoring system at the member state level, aimed at supporting the transition to more sustainable forms of land use [1].

2.2. The European Green Deal

This is a strategic framework document aimed at transforming Europe into a fair, resilient, and prosperous society based on a modern, low-carbon economy with efficient use of natural resources. The key goal of this transformation is to achieve climate neutrality by 2050, meaning a net-zero balance of greenhouse gas emissions.

The European Green Deal serves as the foundational plan for the systematic reduction of greenhouse gas emissions, with a target to reduce emissions by at least 50%, ideally by 55%, by 2030 compared to 1990 levels. This framework also represents the EU’s commitment in the context of international agreements, particularly the Paris Agreement.

As part of the implementation of this strategy, the European Union has committed to reviewing all relevant climate protection policy instruments by 2021. One of the key measures was the evaluation of the Emissions Trading System (EU ETS), including the possibility of expanding it beyond traditional sectors to also include the land use and forestry sector (LULUCF). This effort reflects the growing emphasis on an integrated approach to emissions management across all sectors of the economy and landscape management [2].

2.3. Regulation (EU) 2021/1119 of the European Parliament and of the Council “European Climate Law”

To achieve the climate neutrality goal by 2050, as set by the European Union in accordance with the Paris Agreement, it is essential to involve all economic sectors. This includes energy, industrial production, transportation, heating and cooling of buildings, agriculture, waste management, and also the land use and forestry sector—regardless of whether they are included in the EU ETS (Emissions Trading System).

Achieving climate neutrality requires the inclusion of all sectors where emissions or removals of greenhouse gases occur within the Union’s legal framework. The EU ETS is a key tool in European climate policy and represents the primary mechanism for cost-effective emission reductions.

The EU’s strategic goal is to reach a balance between anthropogenic greenhouse gas emissions and their removal through natural and technological carbon sinks after 2050. Carbon sinks are defined as natural or technical processes that allow for the permanent capture of carbon dioxide in natural or artificially created reservoirs.

From the perspective of natural sinks, the most significant roles are played by the agriculture, forestry, and land use sectors (LULUCF). CO₂ sequestration is recognized in EU legislation as a legitimate contribution to climate goals, but it is subject to a quantitative limit—to prevent excessive reliance on CO₂ removal at the expense of direct emissions reductions. For the period up to 2030, a maximum net contribution from the land use and forestry sector of 225 Mt CO₂ is set, which can be counted towards the EU’s emission targets.

In fulfilling the goals outlined in this framework, the relevant EU authorities and member states are required to prioritize rapid, predictable, and measurable emissions reductions, with the support of emissions removal through natural sinks seen as a complementary tool rather than a substitute for direct mitigation measures [3].

2.4. Regulation (EU) 2023/839 of the European Parliament and of the Council

This regulation confirms the goals set by Council Regulation (EU) 2018/841, specifically the absorption of 225 Mt of carbon dioxide by 2030, with this target being further increased to 300 Mt. This step aligns with the effort to achieve a 55% reduction in greenhouse gas emissions compared to the 1990 baseline. To achieve climate neutrality by 2050 and the subsequent transition to purely negative emissions, it is crucial that the level of greenhouse gas sequestration within the European Union gradually and permanently increases.

In this context, it is also desirable to consider technical solutions such as bioenergy with carbon capture and storage (BECCS) or nature-inspired carbon capture and storage technologies. However, the key role is played primarily by the activities of individual farmers, landowners, and forest managers, who can contribute to increasing carbon stocks through ecosystem-oriented approaches and measures that support biodiversity.

Such measures include nature-based forestry management, establishing fallow lands, expanding agroforestry systems, increasing soil organic carbon content, and wetland restoration. Significant attention is also given to innovative solutions contributing to enhancing the role of soil as a natural carbon sink. All of these measures can be planned and applied in the emerging areas of reclaimed land in post-mining landscapes.

In connection with the implementation of the strategy “Creating a Climate-Resilient Union—The EU’s New Strategy for Adapting to Climate Change,” it is essential to intensify soil monitoring. The goal is to protect and enhance the capacity of natural carbon sinks throughout the European Union. Emission monitoring and reporting systems should be modernized, including through the use of advanced technologies and tools funded by EU programs.

In 2023, Regulation (EU) 2023/839 was adopted, amending the existing Regulation (EU) 2018/841. As part of this revision, the original justification (recital 11), which explicitly stated that the regulation does not impose any obligations on private entities regarding the reporting and accounting of emissions or removals, was removed. The new version of the explanatory statement no longer includes this exception. This opens the door for the possible future involvement of the private sector in mandatory carbon sequestration reporting and monitoring, particularly in the context of certification and trading [4].

2.5. Regulation (EU) 2024/3012 of the European Parliament and of the Council

The above-mentioned European regulation defines the legal framework for the voluntary certification of natural carbon dioxide sequestration within the so-called carbon economy in the sectors of agriculture, forestry, and land use. The regulation distinguishes three main categories of carbon sequestration:

• Permanent sequestration—geological, marine, or technological storage of CO₂ in long-term stable reservoirs;
• Carbon farming—activities related to land and biomass management that lead to an increase in carbon stocks in soil or vegetation;
• Carbon storage in products—long-term storage of carbon in materials with extended lifespans (e.g., construction timber).

All activities within these categories must comply with environmental standards and must not jeopardize other sustainable development goals. Reporting the results requires independent verification by third parties. These entities issue certificates based on an audit aimed at ensuring the credibility and transparency of the declared benefits. The outcome is considered a verifiable net benefit of carbon sequestration or emissions reduction from the managed area.

The qualitative criteria for the certification of carbon sequestration and successful certification depend on meeting the following key principles:

• Measurability and quantification: The activity must be quantitatively assessable and show a net benefit, i.e., the difference between the amount of CO₂ sequestered and related emissions, including indirect impacts (e.g., land use changes);
• Additionality: The certified measure must go beyond common agricultural and forestry practices. Common practices are not eligible;
• Permanence: Certification depends on resistance to the risk of re-emission—geological storage provides the highest certainty, while carbon storage in soil without stabilization measures provides the lowest;
• Do-no-harm: Implemented measures must not lead to significant negative impacts on the environment, biodiversity, or societal interests;
• Third-party verification: Every project must be assessed by an independent auditor before certification and is subject to regular re-certification (at least once every 5 years).

Specifics of Carbon Farming Certification: The certification covers a wide range of activities in the field of carbon farming, including:

• Application of agroforestry, conservation tillage, and cover crop cultivation;
• Leaving land fallow or converting arable land to permanent grasslands;
• Restoration of peatlands and wetland ecosystems;
• Enhancing landscape structure and diversity of landscape elements.

The calculation of sequestration benefits must reflect the specific pedoclimatic conditions of the given location and be compared with the reference level of performance corresponding to the usual practice.

Monitoring and validity of certificates: Due to the potential risk of carbon re-release into the atmosphere, the following requirements are set.

• Long-term monitoring: For carbon storage in products, a minimum of 35 years of monitoring is required;
• Preventive measures: The introduction of appropriate practices to reduce the risk of emissions from natural or anthropogenic causes;
• Time-limited validity of the certificate: The validity period is tied to the level of risk associated with the specific sequestration activity.

Assessment of the development of European legislation in the area of certification and the use of natural carbon reservoirs. An overview of key European legislative documents is given in

Table 1. Overview of EU Legislation on Carbon Sequestration.

Regulation	Objective	Relevance for Post-Mining Areas
EU 2018/841	Ensuring a non-negative CO2 balance in the LULUCF sector by 2030	Supports sustainable land and forest management
EU 2021/1119	EU climate neutrality by 2050	Recognizes sequestration as a legitimate mitigation tool
EU 2023/839	Increasing the sequestration target to 300 Mt CO2	Opens opportunities for the involvement of private entities
EU 2024/3012	Framework for voluntary certification	Introduces tools for measuring and auditing sequestration

[5].

2.6. Conclusions Arising from the Summaries of European Legislation Addressing Emission Reduction and CO₂ Sequestration

From the current development of the European legislative framework focused on the storage of carbon dioxide in natural reservoirs (i.e., carbon sequestration), several key conclusions can be drawn. Carbon sequestration certification is currently operating under a voluntary system, but in the future, it may be integrated into the EU Emissions Trading System (EU ETS). Indications within the legislative development—particularly some Commission proposals and related strategic documents—suggest that, in the long term, a regulated market for certified carbon sequestration units may emerge. This market could either become a direct part of the EU ETS or be closely linked with this system [6].

This approach opens opportunities for both the public sector and private entities to engage in the emerging market through processes of measurement, verification, and certification—potentially representing a new form of environmentally-oriented economic activity.

From the perspective of organizations or individuals who own land, carbon sequestration certification may, in the future, become a tool for increasing land value, for example, through the creation and management of carbon reservoirs. However, it is also essential to consider the potential risk of economic sanctions if increased CO₂ emissions into the atmosphere occur instead of the anticipated sequestration. In such a case, the European Union may require compensation for the negative impact to ensure the achievement of the established carbon neutrality goals.

An alternative scenario remains the possibility that, under pressure from public opinion and the private sector, the current strategy of certifying natural carbon sinks could be mitigated or abandoned. Therefore, the development in this area will continue to depend on the degree of political agreement, the effectiveness of the measures implemented, and the market’s response to the emerging framework for carbon management.

3. Possibilities for CO₂ Sequestration in Soils on Newly Rehabilitated Post-Mining Areas

Reclaimed areas after mineral extraction, particularly from open-pit mining, represent significant anthropogenic landscape units that can play a key role in carbon dioxide (CO₂) sequestration. Mining activities often leave the landscape with degraded or newly created soil, poor in organic matter and nutrients, including organic carbon. This very characteristic, however, presents a high potential for carbon sequestration through vegetation planting or the application of organic materials (such as compost, biochar, digestate), which can sustainably increase the stable carbon content in the soil. The Czech Republic has extensive sites from brown coal mining (Most and Sokolov basins) as well as from hard coal mining (Ostrava-Karviná region), where long-term research on the dynamics of CO₂ storage in soil horizons can take place.

Findings from some studies confirm the possibility of CO₂ sequestration in soil horizons on reclaimed areas. For example, Frouz et al. studied the chronosequences of reclaimed sites in the Sokolov Basin. They showed that the organic carbon content in the soil increases with the age of reclamation, particularly in forested areas. Young reclaimed sites (up to 10 years) had very low values (up to 1% C), while older sites (30+ years) had C content over 2%. The results confirm that long-term successional development and afforestation promote carbon accumulation in the soil [7].

Vinduškováand Frouz conducted a meta-analysis of sites following coal and oil shale mining in the Northern Hemisphere. They found that the rate of carbon accumulation ranged from 0.1 to 1.7 t C/ha/year, depending on the type of reclamation and climate. The greatest effect was achieved through a combination of organic amendments and afforestation [8].

Spasić et al. compared three reclaimed forests of different ages in the Sokolov Basin. The study confirmed that with the age of the forest, not only did the carbon content in the surface layer increase, but there was also the development of a deeper soil profile, which is an indicator of the long-term stability of soil carbon [9].

The results of the study [10] indicate that the type of reclaimed substrate and the method of its modification have a significant impact on the soil’s ability to accumulate soil organic carbon (SOC). A comparison of two sites—one after limestone mining without organic amendments and the other after lignite mining with the application of sewage sludge—showed that the lignite site achieved significantly higher SOC content (1–2% compared to a maximum of 0.3%), lower vertical variability of carbon, and better soil profile development. The use of sludge not only increased biological activity but also contributed to greater carbon stability in the soil, significantly enhancing the potential for long-term CO₂ sequestration. The results confirm that a properly chosen reclamation approach—especially with the use of organic inputs—can significantly affect the carbon balance and climate function of soils disturbed by mining activities.

The research [11], which focused on carbon sequestration in soil and the overall CO₂ balance in a successively reclaimed site 39 years after coal mining in the Sokolov Basin (Czech Republic), highlights the significant ability to sequester carbon into the soil. The ecosystem, dominated by willows (Salix), birch (Betula), and poplar (Populus), functioned in 2023 as a strong carbon sink, with an annual NEE value of ≈ −415 g C/m²/year (~4.15 t C/ha/year). The balance value resulted from GEE ≈ −1423 g C/m²/year and Respiration (Reco) ≈ +1008 g C/m²/year, with seasonal variations driven by increased photosynthesis during the summer. Factors such as temperature, water vapor deficit, and global radiation influenced the intensity of CO₂ exchange between the ecosystem and the atmosphere. This natural process demonstrates that even without active reclamation (natural succession), stable carbon accumulation and ecological function restoration can be achieved on technically disturbed substrates, especially in areas without hydraulic limitations.

The study [12] analyzes various reclamation approaches at mining-disturbed sites and their impact on the accumulation of soil organic carbon (SOC). The results show that actively reclaimed areas—particularly those with the addition of organic materials such as topsoil, compost, or biochar—achieve significantly higher SOC increases than areas left to spontaneous succession. On average, such treated sites show sequestration rates of up to 1.6 t C/ha/year, approximately 2–5 times higher than non-intervened areas. Grasslands exhibited higher sequestration efficiency in the first years compared to trees, and the application of biochar not only increased the absolute amount of SOC but also its stability. The study confirms that a well-chosen combination of substrate and vegetation cover can significantly accelerate the development of the soil carbon pool in post-mining habitats.

Table 2. Overview of Carbon Farming Measures and Their Potential in Post-Mining Landscapes [12].

Carbon Farming Practice	Description/Application	Benefits for Reclaimed Land	Estimated CO2 Sequestration (t/ha/year)
Establishment of Grasslands	Sowing permanent grasses on exposed surfaces	Soil stabilization, rapid increase in soil carbon, erosion control	0.3–0.8
Afforestation/Tree Planting	Planting suitable tree species (e.g., birch, poplar, willow)	Long-term carbon storage in biomass and soil, increased biodiversity	1.0–4.0
Application of Organic Amendments	Compost, digestate, biochar application to soil surface	Boosts organic matter, activates soil microbiota, improves soil structure	0.5–2.5
Agroforestry Systems	Combining trees with agricultural use (e.g., grazing)	Synergistic carbon capture, economic land use opportunities	1.5–3.0
Passive Succession	Allowing vegetation to develop naturally without intervention	Stable ecological development with minimal costs	0.2–1.0
Wetland Restoration/Moisture Retention	Water retention, planting of wetland species	Encourages anaerobic conditions—limits decomposition, protects soil carbon stocks	1.0–2.0
Cover Crops/Intercropping	Sowing plant species outside the main vegetation season	Enhances soil structure, nitrogen fixation, organic matter increase	0.4–1.2

summarizes different reclamation methods with respect to their effectiveness in CO₂ sequestration.

4. Conclusions

Given the current development of European legislation, which, through Regulations (EU) 2023/839 and 2024/3012, is gradually introducing a framework for the certification of carbon storage in the land use sector, it is clear that the requirements for carbon sequestration in soil horizons will soon become not only a desirable but potentially also a mandatory measure within EU climate policy. Reclaimed areas after mining activities represent a strategic opportunity in this context—these are soils with a low baseline organic carbon content but with a high capacity for carbon accumulation when suitable practices are applied. Scientific knowledge clearly confirms that the combination of organic amendments and the successional development of vegetation can lead to stable, long-term increases in soil carbon stocks in these areas. Given the expected inclusion of the LULUCF sector in the Emissions Trading System (EU ETS) and the creation of a regulated market for certified sequestrated CO₂ units, active carbon management on reclaimed areas could not only be ecologically meaningful but also economically advantageous—both for mining companies and for landowners and managers of reclaimed areas. Introducing carbon sequestration certification also brings certain challenges. The main ones include the financial costs of certification and the need for long-term monitoring. This can be especially demanding for small landowners or municipalities. To ensure successful implementation, it will be important to provide accessible procedures, expert support, and potentially financial assistance from the state or the EU.