Introduction

Wine production, an integral facet of several cultures in the world, stands as one of the most venerable industries within the food and beverage sector1. As per the International Organization of Vine and Wine2, the world in the year 2021 witnessed an overwhelming production of 26 billion litres of wine, translating to a market value of USD 205 billion. The global relevance of wine cannot be undermined as the total wine production in countries like Italy, France, Spain, USA, Argentina, Australia, Chile, and South Africa alone accounts for 76%3. However, the wine industry is compelled to embrace sustainability in response to the challenges posed by climate change, as articulated in the United Nations Sustainable Development Goals (UN SDGs) and the Paris Agreement. Sustainable viticulture now features prominently on the agenda of leading wine-producing nations, reflecting a collective commitment to environmental stewardship. In fact, the United Nations Environment Programme and the European Union have emphasized the importance of eco-innovations in driving sustainable development4,5,6,7. Innovation-driven processes, particularly eco-innovations, offer an effective pathway to reduce the carbon footprint (CF) and contribute to global targets such as the UN SDGs8,9,10. Eco-innovation, defined as any innovation that reduces environmental impact, enhances resilience to environmental pressures and uses natural resources more efficiently, is central to sustainable agriculture and industry transformation11,12. The principles of Circular Economy (CE) and eco-innovation, now central to the diverse activities ranging from fisheries to agriculture13, are becoming instrumental in redefining the wine industry sustainability approach. By intertwining circularity with SDGs, as seen in other sectors8,14, the wine industry can leverage metrics to more tangibly measure sustainable outcomes15.

In a world that is striving to achieve net-zero emissions and address pressing sustainability concerns, whether it be through seaweed farming or wastewater innovations16,17,18, the wine industry adaptations are particularly salient. The policy landscape, increasingly governed by the CE concept, prompts industries to reevaluate and restructure19,20,21,22. Eco-innovations, analogous to those reshaping agriculture and other sectors23,24,25,26, recommend a paradigm shift in wine production to promote an environmentally conscious approach for low CF8,27,28,29,30. This study aims to underscore the role of eco-innovation in aligning with SDG 9, which promotes resilient infrastructure, inclusive and sustainable industrialization, and fosters innovation to reduce the CF in wineries. We therefore analysed the currently available life cycle assessments (LCAs) used in wineries and highlighted the undermined resources in farming practices, biogenic emissions, and wastewaters. By applying eco-innovative integrated resource recovery models, we demonstrate their synergy with SDGs other than SDG 9 and show that adopting these models can significantly reduce the CF in vineyards.

Results and discussion

Eco-innovation and sustainability: shaping the future of winemaking

SDG 9 is pivotal for innovation and sustainable infrastructure, essential for a more sustainable and resilient future31. In the wine industry, transitioning from a linear to a circular economy (CE, i.e., involves carbon farming, waste management, and low carbon technologies), eco-innovative models have been largely recognized as integral to the sustainability27,28,29,30. Across the globe, wineries32,33,34,35,36,37 have been developing sustainability plans to reduce carbon emissions, with several countries or regions leading in wine production pioneering these efforts. This approach not only aligns with the holistic practices of viticulture and winery operations but also resonates with SDG 9 emphasis on infrastructure and industrial innovation. To provide a comprehensive understanding, we have mapped the types of eco-innovation to the sustainability indicators such as biodiversity, energy efficiency, CF, waste and circularity, logistics, and society and community, widely used globally in the wine industries (Table 1). These indicators were selected based on their relevance to the key environmental and social challenges faced by the wine industry world-wide, their frequent use in sustainability reports32,33,34,35,36,37 to ensure consistency and comparability, and their comprehensiveness in covering environmental, economic, and social dimensions. For instance, the incorporation of biodiversity conservation practices in Great Britain32 and Australia36 reflects their commitment to promote Resilient Infrastructure (SDG 9.1). Energy efficiency initiatives in New Zealand35 align with SDG 9.2 by integrating sustainable practices in industrial processes. The adoption of non-chemical pest management practices in Italy34 and the USA37 supports SDG 9.4, highlighting the efforts to retrofit industries with sustainable technologies. Furthermore, the categories of eco-innovation like Organization, Process, Product, and Marketing, were chosen to capture the broad range of innovative practices26 that can be adopted in the wine industry. These categories reflect different aspects of the innovation process such as innovations in management practices and organizational structure, improvements in production processes and operational efficiency, development of new or improved products that offer environmental benefits, and strategies to promote sustainable products and practices to consumers26.

Table 1 Mapping of eco-innovation measures, categories and present sustainability indicators widely used in the wine industries across the globe
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In fact, the assessment of eco-innovation types against the specific targets of SDG 9 reveals a detailed alignment (Table 2). For instance, organizational innovations, such as developing small-scale sustainable practices and enhancing financial and credit access for wineries, align with SDG 9.3. Additionally, energy efficiency initiatives and non-chemical pest management practices map onto SDG 9.4, which aims at retrofitting industries towards sustainable practices. The integration of research and innovation in ecological practices, as seen in the USA, aligns with SDG 9.5. This mapping demonstrates a clear correlation between current practices in the wine industry and SDG 9 targets. Thus, the eco-innovative measures reflect a paradigm shift, indicating a move beyond the adoption of technologies to a fundamental change in the industrial approach to sustainability28,29,30. This shift is not without its challenges, requiring investment, training, and cultural adaptation, but the long-term gains, such as increased efficiency, reduced environmental impact, and alignment with global sustainability goals, underscores its value28,29,30. The integration of eco-innovation within the industry is thus an evidence of its commitment to SDG 9, ensuring that the sector’s progression towards sustainability is both meaningful and measurable.

Table 2 Mapping of SDG 9 targets with the present eco-innovation types in the wine industry
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Resource loop: an overlooked aspect in winery CF

As wineries continue to integrate sustainable practices in line with SDG 9, it is essential to address all potential sources of emissions to achieve a comprehensive reduction in the CF. According to Navarro et al.28, the main contributors to CF are viticulture (27%), winemaking (23%), and wine bottling (50%). Chiriaco et al.38 opined that winemaking and bottling are accountable for 85% of the total CF of a wine bottle. Recent sustainability reports from California and Wine Australia regions also corroborate with the above LCA summary and identify packaging, field emissions after fertilization, electricity use, and logistics supply chain as ‘hotspots’32,33,34,35,36. Furthermore, the present data clearly suggest that the traditional LCA approaches being comprehensive often underestimate the total GHG emissions associated with winemaking. Such a discrepancy arises primarily from overlooking key resources like CO2 from fermentation, wastewater, and soil carbon fluxes.

In view of the above, we performed a global data analysis of biogenic fermentation of CO2 (Fig. 1a) and wastewater generation (Fig. 1b), which significantly contribute to the industry’s overall environmental impact. This analysis also revealed significant emissions that are not typically accounted for in conventional LCA models. For instance, estimates of biogenic fermentation reveal an annual average of 217 × 103 tonnes CO2-eq. with a range of 83‒497 × 103 tonnes CO2-eq. Our further comprehensive analysis of emissions from wastewater, based on data from 40 studies, highlights distinct patterns in chemical oxygen demand (COD) and total nitrogen (TN) across the continents (Fig. 1c, d), which is a common source of emissions that has been accounted from wastewaters39,40,41,42,43. For instance, according to the National Greenhouse Gas (GHG) Inventory44, the inclusion of direct GHG emissions, collected from the onsite centralized wastewater treatment, resulted in doubling the total Australian GHG emissions, suggesting the need for wastewater strategy initiatives across the states45. Similarly, according to the US EPA44,46, the global emissions of methane (CH4) and nitrous oxide (N2O) from domestic wastewater are estimated to increase by 20‒35% in the next 50 years.

Fig. 1: Estimated CO2 emissions (tonnes, t) from wineries.
figure 1

a Fermentation process, and (b) Wastewater generation (megalitres, ML) from wineries across different regions of the world. Extent of pollution from winery wastewater and greenhouse gas (GHG) emissions in different continents and regions of the world. Global emissions of (c) Methane, CH4 (g kg–1 COD), and (d) Nitrous oxide, N2O (g kg–1 TN).

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Following the emission factors47, an empirical data analysis was performed to determine potential emissions of CH4 and N2O from winery wastewater, and the results are presented in Fig. 1c, d. A comparison of these data across the continents reveals that Europe showcases a broad spectrum of CH4 emissions, ranging from minimal values to as high as 5726.40 g kg‒1 COD and N2O emission of 7.391 g kg‒1 TN. This spectrum indicates the use of diverse wine production techniques and wastewater management practices across the countries. This variability underscores the importance of considering regional practices and production techniques in GHG emission calculations48. Although significant efforts have been focused on primary operations and infrastructure, even minor sources of emissions are likely to play a crucial role in the overall sustainability of the industry. Studies of Bosco et al.49 and Vendrame et al.50 indicate that a proper quantification of biogenic carbon fluxes can substantially offset emissions, suggesting that the actual CF may be lower than that reported. According to Brandão et al.51 and Marras et al.52, a realistic LCA that includes biogenic carbon/CO2 fluxes is needed to provide a comprehensive assessment of the GHG budget of wine production. This shift could not only aid in reducing GHG emissions but also result in economic benefits for wineries. In conclusion, a more holistic approach to assessing the environmental impact of wineries is necessary. By including the often-overlooked aspects of CO2 from fermentation and wastewater treatment, we gain a clearer understanding of the true CF associated with wine production. This comprehensive approach is essential for developing effective strategies to reduce the environmental impact of the winery industry and achieve resource conservation and environmental regulation compliance.

Need for adopting the eco-innovative resource recovery model

Innovations in wastewater treatment and carbon capture, integral to this transition, embrace CE principles, focusing on minimizing waste and maximizing resource efficiency18,48. Long-standing wastewater treatment plant practices, while effective in contaminant removal, often lead to increased energy consumption and GHG emissions53. Based on the integrated LCA and economic analysis, Zhang et al.54 showed that the total impact of carbon emissions was strongly dependent on the influent conditions, and the incorporation of resource recovery in wastewater treatment plants improved the environmental performance. We propose the adoption of eco-innovative (low-carbon) resource recovery models like Constructed Wetlands (CW) and Phycosol to address these challenges, offering a more sustainable approach to winery operations and UNSDGs. Phycosol, for instance, integrates solar technologies with microalgal systems, transforming wastewater into valuable products like biofertilizers55, while CW effectively treats winery wastewater with lower CFs56. Also, Kuppan et al.56 recently demonstrated a 94% reduction in GHG emissions with Phycosol besides a significant production of biogas and biofertilizers, emitting 0.17‒0.52 kg CO2 kg–1 of biomass as compared to the traditional microalgal routes. Similarly, CWs are effective in treating winery wastewater with lower CFs56,57. CWs utilize natural processes involving soil, vegetation, and associated microbial ecosystems to treat wastewater efficiently, and are shown to reduce CO2 emissions significantly when compared with the conventional wastewater treatment systems57. Studies of Garfí et al.58 and Lutterbeck et al.59 highlighted low energy requirements and high nutrient removal efficiency of CWs. In fact, the organic removal rates in CWs were up to 10 kg COD m−2 d−1 as against to 0.01–0.03 kg COD m−2 d−1 in conventional systems. Another salient challenge in this context is the management of wastewater treatment and its concomitant GHG emissions. While investigating GHG emissions (m−3 of treated wastewater) during activated sludge process (ASP) of winery wastewater treatment, Flores et al.60 reported 239‒282 kg CO2, 0.08 kg N2O, and 0.20‒0.40 kg CH4. It is important to note that these figures can vary significantly depending on the type and composition of the wastewater (Fig. 1c, d). Although winery wastewater typically exhibits low nitrogen content and N2O emissions, even if low, warrant attention. According to the International Protocol for GHG emissions in grape and wine production61, emissions from the wastewater treatment, when processed on-site, should be classified under Scope 1 (Direct), and Scope 2 (Indirect). Rosso and Bolzonella62 reported that the CF for an aerobic winery wastewater facility was between 9.86 and 17.10 kg CO2-eq m−3 of treated wastewater. In a comparative study on wastewater treatment, Flores et al.63 underscored transportation, chemicals, and electricity consumption as pronounced contributors to GHG emissions.

Closing the resource loop and its ripple effect on reducing overall CF: the role of eco-innovation

Our present LCA findings clearly illustrate the distribution of fossil and biogenic CFs across different farming types (Fig. 2). The median values for fossil CF are the highest for conventional farming, followed by mixed and organic farming. Thus, conventional farming has a wider range and higher median values for both fossil and biogenic CFs as compared to mixed and organic farming types, indicating that conventional farming methods may have a higher environmental impact in terms of carbon emissions. Furthermore, this analysis reveals that organic farming tends to have lower fossil carbon emissions, which could be attributed to practices that reduce the use of synthetic fertilizers and fossil fuels. In contrast, handling of grape stalks at wineries involves ploughing them back into the soil for contributing to the short-term carbon cycle64. This practice complicates the input data for LCA models, as it does not fit neatly into software guidelines that typically assume landfill disposal. Consequently, emissions from such practices are often excluded from CF calculations although they can contribute to CO2 sequestration.

Fig. 2: Comparison of conventional and eco-innovation models for GHG emissions in winery processes.
figure 2

Top panels: Box plot of LCA showing fossil and biogenic carbon footprint (CF) for conventional, mixed, and organic farming types in wine production. Bottom panels: Comparison of greenhouse gas (GHG) emissions (CH4 and N2O) from various winery wastewater treatment processes, including activated sludge process (ASP), constructed wetland (CW), and Phycosol.

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The adoption of eco-innovative models for the utilization of these underappreciated resources (<1% emissions) thus demonstrates the ability to close the resource loop. A consideration of COD and TN values for exploring the emission rates in different treatment methods reveals that ASP tends to have significantly higher CH4 emissions (0.225 – 2700 g kg‒1 COD) when compared with eco-innovative methods like CW and Phycosol (Fig. 2). Phycosol, notably, registers zero CH4 emissions, highlighting its potential sustainability advantage. According to Garfí et al.58, both CW and high rate algal pond system are nature-based technologies that present lower environmental impacts as compared to conventional systems like ASP. Their study also highlighted that nature-based systems are more environmentally friendly due to lower energy and chemical consumption. Specifically, the potential environmental impact of conventional wastewater treatment plants was found to be 2–5 times higher than that of nature-based systems depending on the impact category. Our comparison of the three treatment processes, viz, ASP, CW, and Phycosol (Table 3), clearly revealed a potential emission reduction of 0.09‒381.61 g CO2-eq bottle–1 of 750 mL wine. These results align with the findings of Garfí et al.58, which indicate that CWs emit significantly less CH4 and N2O when compared with the traditional system of ASP. Thus, the variability in emission rates observed across different continents emphasizes the influence of regional practices and production techniques on GHG emissions58. Further, we determined the potential carbon fixation during microalgae-based winery wastewater treatment systems and CO2 supplied from the winery fermentation process. Using the volumes of wine production from the top 10 wine-producing countries and assuming that microalgae are grown under mixotrophic conditions, our analysis revealed a potential capture of 2.73 g CO2 L‒1 of winery wastewater (Supplementary Table 1), which amounts to around 10.90 g CO2 sequestration bottle–1 of 750 mL wine. Our present findings on the carbon sequestration potential of Phycosol are in line with those of Praveen et al.55, which corroborate the efficacy of microalgae in capturing CO2 and converting it into biomass. This process not only mitigates GHG emissions but also provides a renewable source of biofertilizers. Therefore, incorporating the Phycosol system into winemaking operations not only facilitates efficient waste management and resource recovery but also significantly contributes to the reduction of CF in the industry.

Table 3 Benefits of Phycosol strategy in reduction of CF in wineries
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In addition, the utilizaiton of biomass from Phycosol process is hypothsized to show the ripple effect on reducing the vineyard emissions. For instance, agriculture practices such as the application of chemical fertilizers from vineyards are regarded as contributors to GHG emissions, especially nitrous oxides32,33,34,35,36,37. In this context, data on some widely applied fertilizers in vineyards, their corresponding nitrogen content, and estimated GHG emission using emission factors expressed in CO2-eq are summarized in Supplementary Table 2 and 3. The N2O emission can be influenced by many factors, including soil pH, soil carbon, nitrate, and moisture content. For example, the reported emissions of N2O (as g N2O-N ha‒1 day‒1) from the undervine area of Hunter Valley in Australia were in the range of 0.18–0.4365. Based on our analysis, the use of synthetic nitrogen (N) fertilizers in vineyards accounts for an estimated Scope 3 emission of 0.13‒1.11 kg CO2 kg‒1 of N fertilizer applied which corresponds to 5.70‒49.30 g CO2-eq bottle–1 of 750 mL wine produced (Table 3 and Supplementary Note 1). In addition, delving into the indirect emissions by replacing synthetic fertilizers with an eco-innovative Phycosol model enhanced by solar technologies has the potential to produce microalgal biomass directly within the vineyards, eliminating these emissions56.

To assess the emission reduction capabilities of microalgal biomass produced from Phycosol, as a substitute for synthetic fertilizer, three forms, viz., de-oiled biomass, lipid-extracted microalgal biomass, and fresh biomass, were used in a ratio of 1:1 (Supplementary Table 4). Our analysis indicates that replacement of synthetic N fertilizers with the microalgal biomass in vineyards helps to reduce N2O emissions (Scope 1) by 12‒16 g CO2-eq bottle–1 of 750 mL wine (Fig. 2). Adopting de-oiled microalgal biomass as a fertilizer replacement results in the most pronounced reduction in emissions. However, the efficacy of this solution will depend on microalgal species and growth conditions, necessitating further research. These results are also in line with the findings of Menegat et al.66 and De Rosa et al.67 who reported a significant reduction in N2O emissions when synthetic fertilizer was replaced with organic fertilizer (manure). Similarly, Liu et al.68 showed that the simultaneous application of both synthetic N fertilizer and organic fertilizer (made of animal and plant sources), resulted in a 14.30% reduction in GHG emissions, while the reduction was highly significant (28%) with the use of dry organic fertilizer. In general, the use of organic fertilizer, in comparison with synthetic N fertilizer alone, not only substantially lowered N2O emissions caused by fertilizers and N leaching but also promoted fertilizer-induced ammonia volatilization67. Mitigation of N2O emissions is possible when the fertilization process includes minimal water, limited bare soil, effective residue management, and N immobilisation66,67. In the broader quest for a sustainable winemaking process, the Phycosol model champions a circular approach. By categorizing emissions under direct and indirect channels and by adopting Phycosol as a strategy of elimination, substitution, and sequestration, the potential emission reduction observed was 28.60‒457.81 g CO2 bottle–1 of 750 mL wine (Table 3). Although this reduction is a fraction of the total CF, the use of Phycosol can be a vital step in utilizing waste resources for tangible benefits. Thus, the integration of Eco-innovation model such as Phycosol in winery operations offers dual benefits of reducing the CF and providing economic advantages through resource recovery. The recent emergy analysis by Praveen et al.55 also supports the sustainability of integrating solar technologies with microalgal cultivation for enhancing the overall environmental performance of wastewater treatment systems.

Interlinking eco-innovation and UN SDGs in winemaking

To address the economic aspects of adopting eco-innovative models in the wine industry, we conducted a detailed techno-economic analysis (TEA) based on the studies of Garfí et al.58. The TEA suggests that CW and Phycosol systems not only have lower capital and operational costs (two-fold) but also significantly reduce CO2 emissions. Specifically, CW and Phycosol can reduce emissions by ~41.36 kg CO2-eq and 50.22 kg CO2-eq person–1 equivalent yr–1, respectively. These savings can significantly contribute to the overall lower CFs and align with the CE principles.

By integrating eco-innovation, wineries can align with key SDGs, promoting a shift from conventional methods to more sustainable, circular business models. These models present a viable alternative to Conventional ASP, as evidenced by their alignment with the relevant SDGs (Fig. 2; Emission profiles presented in Supplementary Data 6 in the figshare repository:) and their potential to mitigate carbon emissions18. To substantiate this claim, we mapped these technologies across a wide range of SDGs (Supplementary Table 5), and the results reveal that transitioning to these models can enhance environmental sustainability, align with various SDGs (Fig. 3a, Supplementary Table 5) and offer solutions to the often-overlooked aspects of winery operations. While all three systems, i.e., Phycosol, CW, and CAS, meet the objectives of the SDGs, the extent of their relevance varies, reflecting the different focuses and efficacies of each model. Notably, certain SDGs stand out for their noteworthy influence on eco-innovation within wineries. For instance, SDG 6 (Clean Water and Sanitation), and SDG 12 (Responsible Consumption and Production) are highly pertinent, as they are related to practices that mitigate the environmental impacts of winemaking. Other SDGs, such as SDG 7 (Affordable and Clean Energy), and SDG 13 (Climate Action), demonstrate moderate relevance through their roles in promoting renewable energy and climate mitigation strategies. The remaining SDGs are concerned with the wine industry through broader socio-economic and environmental considerations, highlighting the comprehensive nature of sustainability in winemaking. Thus, varying levels of engagement with each SDG between these models suggest that while conventional systems provide a baseline for sustainability, targeted eco-innovative models like Phycosol and CW offer enhanced benefits as compared to CAS (Fig. 3 and Supplementary Table 5). In addition, Following the available reports in the literature69,70,71, we employed the Seven-Point Scale framework for assessing eco-innovation practices against SDG targets. In analysing the interplay between eco-innovation in winemaking and SDGs, our study identifies significant interactions across multiple SDGs, mirroring the complex interdependencies found within global sustainability objectives (Supplementary Table 6). We observe a predominance of positive interactions (synergies) that demonstrate how eco-innovative practices show strong synergies with the goals targeting industry, innovation, and infrastructure (SDG 9), responsible consumption and production (SDG 12), and clean water and sanitation (SDG 6), reinforcing the sustainable management of natural resources and efficient production processes (Fig. 3b, Supplementary Table 6). Interestingly, while eco-innovation is conceptually tethered to SDG 9, promoting innovation and infrastructure, our nuanced findings reveal significant interactions with SDGs, particularly 6 and 12, which emphasize clean water and sanitation, and responsible consumption and production.

Fig. 3: Chord diagram of relevant SDG targets and their interactions with eco-innovative resource recovery technologies and practices in winemaking.
figure 3

a Mapping of relevant SDG targets with eco-innovative resource recovery technologies, including conventional activated sludge process (ASP), constructed wetland (CW) treatment, and Phycosol, for the treatment of winery wastewater, and (b) Positive interactions between SDGs and eco-innovative practices, specifically under SDG 9 (Industry, Innovation and Infrastructure), SDG 6 (Clean Water and Sanitation), and SDG 12 (Responsible Consumption and Production) in the winemaking process.

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Our further analysis indicates more focused interactions for SDGs 6.3, 6.6, 12.4, and 12.5. Specifically, SDGs 6.3 and 6.6, relating to water management, and SDGs 12.4 and 12.5 that focus on responsible waste management, are the fewer but more targeted interactions (Fig. 3b and Supplementary Table 6). This highlights that, while eco-innovations contribute broadly across SDGs, their most profound impacts in specific areas such as water management and waste reduction are essential for the sustainable transformation of winemaking practices. The present observation is also in line with other findings of multiple synergies and trade-off were identified with each goal and its targets10,70. Also, this approach also demonstrates the advantage of adopting eco-innovation model addressing wider environmental factors through SDGs, which is far exception than widely applied approaches such as water‒energy‒food or water‒energy72,73. Our study suggests that, while SDG 9 provides a valuable framework for integrating innovation within industrial processes, the actualization of sustainability goals in the context of wineries is more dynamically related to water management and sustainable production practices. Incorporation of biogenic carbon fluxes and soil carbon sequestration, particularly in organic farming practices, can further enhance the sustainability of these systems in winemaking. Thus, the studies of Chiriacò et al.38 and Bosco et al.49 emphasized the potential of biogenic carbon sequestration in vineyards, which can substantially offset emissions and provide a more accurate LCA. Embracing SDG 9 through eco-innovation allows wineries to move towards more sustainable, efficient, and innovative practices. The transition to eco-innovative models like Phycosol and CW also aligns with consumer trends and willingness to pay for sustainable products. According to the recent market insights74, the demand for organic and sustainably produced wines is fast growing, with consumers willing to pay a premium for environmentally friendly practices. This trend underscores the economic viability of adopting such models, as wineries can leverage their sustainability credentials to attract eco-conscious consumers.

Conclusions

Our perspective, based on available scientific data and analysis, affirms the pivotal role of eco-innovation in revolutionizing the wine industry, marking a significant shift from conventional practices toward sustainable and resource-efficient methodologies. Through the lens of UN SDGs, particularly SDG 9, our approach of adopting eco-innovative technologies like Phycosol and CWs showcases not only a solution to substantially reduce carbon emissions but also a pathway to enhance the holistic sustainability of wine production processes. Although wastewaters and fermentation wastes account for <1% of the total CF, their reduction is strategically important. Innovations like Phycosol and CWs turn waste into valuable resources, such as biofertilizers and biogas. This aligns with CE principles, enhancing resource efficiency and reducing waste. Our present findings illuminate the dual benefits of these eco-innovations: a marked reduction in the CF by 25‒30% bottle–1 of 750 mL wine and a reinforcement of the wine industry commitment to environmental stewardship. Further, adopting this eco-innovation under SDG 9 (Industry, innovation and infrastructure) supports SDG 6 (Clean Water and Sanitation) and SDG 12 (Responsible Consumption and Production). Small reductions across numerous wineries can aggregate into a significant decrease in overall industry emissions. When each winery makes even minor improvements, the cumulative effect on a global scale can be substantial. These broader environmental benefits contribute to the sustainability goals beyond just CF reduction. Therefore, our study extends an invitation to policymakers, industry stakeholders, and the research community to consider these findings as a call to action. By embracing eco-innovation, we can collectively drive the wine industry – and indeed the broader agricultural sector – towards a future where sustainability is not just an aspiration but a realized practice, ensuring the preservation of our planet for future generations.

Methodology

Mapping eco-innovation and sustainability indicators in winemaking

To provide a comprehensive understanding of eco-innovation in the winemaking industry and its alignment with SDGs, we adopted a rigorous methodological framework. This framework is based on established methods available in the literature and aims to systematically map the types of eco-innovation to the widely used sustainability indicators in the global wine industry.

Selection of sustainability indicators

The following criteria were used to select the sustainability indicators:

  1. 1.

    Relevance to key environmental and social challenges: Indicators were chosen for their significance to the primary environmental and social issues faced by the wine industry globally.

  2. 2.

    Frequency of use in sustainability reports and literature: Indicators commonly used in sustainability reports and academic literature were selected to ensure consistency and comparability.

  3. 3.

    Comprehensiveness in covering environmental, economic, and social dimensions: The selected indicators provide a holistic view of sustainability by addressing environmental, economic, and social aspects.

The chosen indicators include biodiversity, energy efficiency, carbon footprint, waste and circularity, logistics, and society and community.

Classification of eco-innovations

Eco-innovations were categorized into four types: Organization, Process, Product, and Marketing. This classification captures the broad range of innovative practices adopted in the wine industry:

  1. 1.

    Organization: Innovations in management practices and organizational structure.

  2. 2.

    Process: Improvements in production processes and operational efficiency.

  3. 3.

    Product: Development of new or improved products that offer environmental benefits.

  4. 4.

    Marketing: Strategies to promote sustainable products and practices to consumers.

Mapping eco-innovation to SDG targets

To map eco-innovation practices against specific SDG targets, we employed a systematic approach inspired by literatures8,71,75. The process involved the following steps:

  1. 1.

    Identifying key SDG targets: We identified SDG targets most relevant to the wine industry, focusing on those directly impacted by eco-innovation practices.

  2. 2.

    Mapping practices to SDG targets: Eco-innovation practices were mapped to relevant SDG targets using a qualitative assessment of their contributions to sustainability goals.

  3. 3.

    Scoring interactions: Using a seven-point scale, we rated the interactions between eco-innovation practices and SDG targets, ranging from +3 (indivisible) to –3 (cancelling), as proposed by Nilsson et al.71.

CO2 fixation efficiency

CO2 sequestration technique in microalgal system can be achieved either by direct sparging or absorption units. While the direct sparging technique is seen inefficient due to low water solubility of CO2 and acidification of the culture medium, aqueous solution of NaOH was used for CO2 capture. When dissolved in liquid, CO2 will be in four inorganic carbon forms ‒ carbonate ion (CO32−), bicarbonate ion (HCO3−), carbonic acid (H2CO3), and dissolved CO2. However, during the carbon fixation in photosynthetic microalgae, the Rubisco enzyme (carboxylase/oxygenase) will solely react with CO2, and once it reaches saturation, another enzyme, carbonic anhydrase (CA), converts the carbonic and bicarbonate acids into CO2, which can be transformed into biomass. In general, the carbon fixation produces final products of carbohydrates, \([{{{{{\rm{CH}}}}}_{2}{{{\rm{O}}}}}]_{{{{\rm{n}}}}}\). The light-dependent (Eq. 1) and independent (Eq. 2) reactions of microalgal CO2 is as follows76:

$${H}_{2}O+{{CO}}_{2}+{Photons}\left({light}\right)\to [{{{CH}}_{2}O}]_{n}+{O}_{2}+{H}_{2}O$$
(1)
$${{CO}}_{2}+{4H}^{+}+{4e}^{-}\,{\to }^{2{NADPH},\,3{ATP},{Enzymes}}[{{{CH}}_{2}O}]_{n}+\,{H}_{2}O$$
(2)

The amount of CO2 fixed by microalgae can be determined using the following chemical reaction of photosynthesis:

$$4{{{{\rm{CO}}}}}_{2}+{{{\rm{Nutrient}}}}+{{{{\rm{H}}}}}_{2}{{{\rm{O}}}}+{{{\rm{Light}}}}\to 4{{{{\rm{CO}}}}}_{0.48}{{{{\rm{H}}}}}_{1.83}{{{{\rm{N}}}}}_{0.11}{{{{\rm{P}}}}}_{0.01}+(3/2){{{{\rm{O}}}}}_{2}$$
(3)

Similarly, when the pH ranges from 6 to 9, bicarbonate is the predominant form of inorganic carbon in water, facilitating the action of external carbonic anhydrase and promoting the active transport of this carbon source into microalgal cells. However, at a lower pH range of 5 – 7, CO2 uptake occurs via diffusion. In cultures aerated with only atmospheric air, CO2 uptake is likely mediated by active transport due to the high pH levels (between 6.96 ± 0.01 and 10.80 ± 0.10) observed in the selected microalgal cultures. In contrast, when CO2-enriched air is used, the pH drops, suggesting that CO2 uptake under these conditions likely occurs through diffusion.

Thus, the high-purity CO2 in liquid or gaseous form serves as a source of inorganic carbon, and the abundance of nutrient-rich wastewaters containing a significant amount of organic carbon can ensure that it is not a constraint for microalgal growth. The efficiency of CO2 capture is largely influenced by various factors such as pH, wastewater characteristics, type of microalgal strain chosen, CO2 concentration, design of bioreactor model, environmental conditions, and operating conditions. Generally, different CO2 concentrations are used for determining CO2 fixation efficiency. The removal efficiency is determined by:

$$\frac{{{CO}}_{2}{in\; Influent\; gas}-{{CO}}_{2}{in\; Effluent\; gas}}{{{CO}}_{2}{in\; Influent\; gas}}\times 100 \%$$
(4)

To evaluate the bio-fixation efficiency, it is crucial to measure biomass and growth rates77. In optimal conditions, the efficiency of CO2 capture can be as high as 80‒99%78. Moreover, when exposed to high concentrations of CO2, algae can adapt and improve their fixation abilities. Gradual increase in CO2 supply can therefore result in higher fixation and growth rates. According to Schenk et al.79, enriching photoautotrophic microalgal cultures with CO2 can lead to a significant increase in biomass. However, it is important to note that there is a maximum CO2 concentration for this increase to occur. Nagase et al.80 and Matsumoto et al.81 reported that the optimal CO2 concentration for Tetraselmis sp. and Dunaliella tertiolecta is ~15%, while Hanagata et al.82 found that Scenedesmus sp. can tolerate CO2 concentrations up to 80%, indicating the varied concentration levels that microalgae can consume for the growth.

In the present study, we determined the photoautotrophic and mixotrophic microalgal carbon fixation using the amount of carbon stored in algal biomass (CTotal), the amount of carbon present in consumed glucose (CHetero), and the amount of carbon that was obtained by the microalgae from CO2 (CAuto) in Supplementary Table 4 using the following Eqs. 5, 6 and 7 as per Subramanian et al.83.

$${C}_{{Hetero}}=\left({G}_{{Initial}}-{G}_{{Final}}\right)\times \frac{{n}_{c}\times {{MW}}_{c}}{{{MW}}_{{oc}}}$$
(5)
$${C}_{{Total}}=\left({X}_{{Final}}-{X}_{{Initial}}\right)\times \frac{100-A}{100}\times \frac{C}{100}$$
(6)
$${C}_{{Auto}}={C}_{{Total}}-{C}_{{Hetero}}$$
(7)

where, nc represents the number of carbon atoms in one molecule of glucose (C6H12O6), MWC is the atomic weight of carbon (g gmol‒1), MWOC is the molecular weight of organic carbon source (g gmol‒−1) A is the ash content of the biomass (g) and C is the carbon content of biomass (g). For glucose, the values of nC, MWC and MWOC are 6, 12 and 180 g gmol−1 respectively. Here we assumed the minimum COD of 320 mg L‒1 and the biomass productivity as 1.0 g L‒1 and glucose value as 30% of total COD winery wastewater84. Similarly for the rate of CO2 fixation in mixotrophy mode determined by the following Eq. (8) as described by Tang et al.85.

$${C}_{{Mixotrophic}}\left(g{L}^{-1}{d}^{-1}\right)={C}_{C}\times {\mu }_{L}\frac{{{MCO}}_{2}}{{M}_{C}}\frac{(44)}{(12)}$$
(8)

where, CMixotrophic is the rate of CO2 fixation (g L‒1 day‒1), Cc is the carbon content of the algal biomass produced from CO2 fixation, µL is the biomass productivity (g L‒1 day‒1), MCO2 is the molecular weight of carbon dioxide and MC is the molecular weight of carbon. In this study, we assumed the productivity of biomass as 1.0 g L‒1 day‒1 for mixotrophic mode.