ANNEX 2 – LINKAGES BETWEEN CIRCULAR ECONOMY, BIODIVERSITY, ECOSYSTEMS, AND CHEMICALS

There are high expectations that the circular economy (CE) can halt biodiversity loss; for instance, the EU’s Biodiversity Strategy considers CE as one solution for using natural resources and investments (European Commission, 2020). The Circular Economy Action Plan aims to implement a growth model that gives more back to the planet than it takes (European Commission, 2020). However, this literature study finds little research investigating the direct link between specific CE strategies, biodiversity, and ecosystem services. Another under-investigated research area is the trade-offs related to the use of chemicals in relation to the circular economy. A literature review was conducted to shed light on these themes.

Figure 10. DISTRIBUTION OF RESEARCH PAPERS

While articles reviewed in the project predominantly point to the potential of mitigating pressure on the environment via recycling building materials, a vast research gap still needs further systematic investigation before we can understand the full implications of the impact on ecosystem services and biodiversity.

Throughout their lifecycle, buildings in Europe are responsible for half of all extracted materials, half of the total energy production, a third of the total water consumption, and a third of the total waste generation (EC, 2022b). The construction and real estate sectors put significant pressure on ecosystems and biodiversity (Hyvärinen et al., 2019) through the decrease and fragmentation of natural habitats (Auvinen et al., 2020). The Global Assessment Report on Biodiversity and Ecosystem Services (Díaz et al., 2019) states that the current deterioration of biodiversity and ecosystem services is unprecedented. According to the International Resource Panel (Díaz et al., 2019), natural resource use and processing are linked with 90 % of biodiversity loss worldwide. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services points to five key drivers of the biodiversity crisis and nature loss: land use and sea use, climate change, pollution, direct exploitation of natural resources, and invasive species (Díaz et al., 2019).

Biodiversity is undoubtedly impacted negatively by changes in land use if the use of natural resources leads to degradation, loss, or fragmentation of ecosystems (Haines-Young, 2009). The impacts of construction on biodiversity arise especially through the extent and intensity of land use, including direct land use, indirect land use from the extraction of raw materials and fuels, and the land use associated with the treatment and disposal of CDW (Ruokamo et al., 2023). Highways and roads often have a high fragmentation impact (Bennett, 2017). While global economic growth is primarily based on extracting and processing virgin raw materials into goods, the increased use of natural resources puts pressure on biodiversity and ecosystem services (Allwood et al., 2011; International Resource Panel, 2019). The building material industry also significantly impacts biodiversity within the habitats in which it operates.

While the direct linkages on mitigating harmful impacts from construction on ecosystem services and biodiversity have not yet been widely and systematically investigated in peer-reviewed articles, some articles cover the indirect linkages between CE in the construction sector and the mitigation of biodiversity loss and ecosystem degradation. Attention is paid to reducing carbon emissions, resource extraction and landfill depletion as areas of concern, mainly covering only one aspect of the CE, namely recycling. While carbon emissions, resource extraction, anthropocentric land use, and landfills do, without a doubt, harm ecosystem services and biodiversity, CE can help mitigate this significant pressure from the construction sector. To what degree CE strategies can mitigate pressure depends on many variables within the local context, including the land cover and functional redundancy of the species and habitats being affected.

The complexity and broad scope of CE, combined with the locality-specific nature of ecosystem services and biodiversity and the fact that impacts from construction are both direct and indirect, make it challenging to develop a single conversion factor that assigns a score to CE strategies from a biodiversity perspective. However, some possible indicators may serve to monitor and quantify changes from CE strategies on the impact of construction; these are the Raw material requirement (RMR), Land use, and Biodiversity loss index. Global warming potential - land use and land use change (luluc) is another more conventional methodology where climate emissions related to land use change are used as a proxy for biodiversity.  

The review indicates that CE often focuses on material efficiency rather than nature conservation. From the perspective of ecosystem service preservation and biodiversity, one must, therefore, consider the risk of the rebound effect

The rebound effect refers to the offsetting of resource savings resulting from efficiency improvements through increased resource use. Studies show that the material efficiency is also likely to enable the superlative rebound effects (Skelton et al., 2020).

if CE strategies are only implemented to support and legitimise the growth paradigm through the relative decoupling of growth from raw material extraction and land use. In other words, if recycling strategies are implemented, but overall material usage continues to grow while current raw material extraction practices are not sustainably managed, then there is little chance that the biodiversity crisis will halt. In the case of substituting non-renewable resources with renewable resources, it is critical to consider that, e.g., the existing forestry industry is already putting significant pressure on ecosystems in the Nordics. These resources must be managed sustainably for the overall environmental benefits to outweigh the negative impact on biodiversity and ecosystems. Some articles, however, suggest that the bio-economy or circular bioeconomy has better restorative potential for sustainable management of natural habitats and ecosystem services than the circular economy principles.

When examining the benefits of CE strategies, it is essential to recognise the importance of limiting the introduction and recirculation of hazardous chemicals. In the construction sector, legacy substances threaten the circular transition. Therefore, it is essential to determine how to be resource-efficient without looping chemicals that can negatively affect biodiversity, ecosystem services, and overall human well-being.

Chemicals in building materials have numerous valuable functions. However, hazardous chemicals in building materials risk contaminating waste streams and water streams, which may later influence humans, biodiversity, and ecosystem services if not appropriately managed (e.g., Bodar et al., 2018; Aurisano et al., 2021; Freige et al., 2018). In the case of implementing CE strategies, the chemicals in these secondary resources may hinder reuse and recycling, and there is a risk that dangerous chemicals cross-contaminate recycled and reused building products.

Reuse and recycling of construction materials can be hindered by the extensive contamination of preservatives, paints and glue, cross-contamination due to lack of selective demolition, legislation, and increased need for manual preparation for reuse (Vis et al., 2016). This highlights the need for material and context-specific risk assessment studies, as some recycled materials may contaminate the built environment. In some cases, hazardous substances from other industries are recycled into construction materials, e.g., ray tubes substituting sand in concrete production containing lead. Using ray tubes in concrete is considered safe because the lead will not release from the concrete. However, consequently, this will triple the amount of hazardous waste in the future, as concrete containing lead cannot currently be recycled (Bodar et al., 2018). Hazardous chemicals also challenge the reuse of building materials because few systems provide the necessary traceability for construction materials. According to Egebæk et al. (2019), the lack of traceability combined with the uncertainty of the chemical content is one of the leading barriers to the increased reuse of building components.

According to Bodar et al. (2018), the linear legislation on the use of chemicals problematises the transition to a circular economy. Currently, the REACH directive primarily hinders using hazardous chemicals in new products. However, it does not concern the waste management of products containing harmful chemicals, as this is a part of the Waste Framework Directive. A critical category (especially within the construction sector) is ‘legacy substances’, which are prohibited by law but are still a part of products currently in use. For instance, asbestos is not permitted in new building materials but is a part of many existing buildings (Bodar et al., 2018). These chemicals may reoccur in the end-of-life phase, when construction waste is deposited or recycled, representing a potential environmental risk for human health and the environment.

As the CE is gaining momentum, the need to reuse and recycle resources is demanded from governmental and non-governmental stakeholders. However, according to Bodar et al. (2019), these demands must balance resource efficiency targets, environmental safety, and public health targets. A more balanced approach could ensure the benefits of the CE and limit the negative consequences of, e.g., legacy substances.

When examining the linkage between CE and chemicals, green chemistry and the principles of green chemistry are reappearing concepts. According to Chen et al. (2020), integrating CE strategies within the principles of green chemistry would contribute to achieving the circular transition, as this would lessen the use and impact of hazardous chemicals. According to Silvestri et al. (2021), using Green Chemistry would contribute to more materials being reused and recycled.