Land Footprint Research Articles

The future of clean energy: Agricultural residues as a bioethanol source and its ecological impacts in Africa

This study presents a comprehensive analysis of Africa's potential to produce bioethanol from agricultural residues and its environmental impact. The relentless consumption of fossil fuels and associated environmental challenges necessitate a shift toward sustainable energy sources, with bioethanol emerging as a promising alternative. This study evaluates the capacity for bioethanol generation from agricultural residues in Africa, considering its land, water, and carbon footprints. Based on data from 85 primary agricultural residues across Africa, approximately 102.256 Gt of fresh agricultural residue is estimated to be available in Africa, translating to approximately 62.117 Gt of dry-weight material. This significant capacity indicates a substantial potential for bioethanol production in Africa, corresponding to a net output of 207.127 EJ. The coproduction potential of bioethanol and electricity are also highlighted, with electricity accounting for 8.016 % of the total net bioethanol energy production. However, the environmental impact of bioethanol production varies across African nations, suggesting the need for optimization and sustainable practices. Additionally, the study discusses the challenges encountered in the bioethanol sector, including the sustainability of production, emission reduction, technological and financial constraints, and the broader context of biomass usage. In conclusion, although bioethanol production from agricultural residues is a promising alternative for Africa's energy sector, it should be realized only after a multifaceted assessment involving technological, economic, policy, and environmental considerations.

Cellular automata modelling to simulate patterns of urban growth for Nusantara: Indonesia’s new capital

This paper uses cellular automata (CA) modelling to simulate possible patterns of urban growth for Nusantara–Indonesia’s new capital. The modelling uses criteria such as projected population growth and planned development stages and a range of relevant factors that influence urban development. Further the study simulates the possible impact of future urban growth on key biodiversity areas (KBAs). Two scenarios were modelled to simulate urban growth patterns–(1) the nature sensitive city and (2) the Indonesian government’s current plan. Results of the scenario-based CA modelling demonstrate that scenario 1 offers a more sustainable and liveable approach to urban growth, despite its larger land footprint. This is achieved by preserving protected and key biodiversity areas, which are essential for the long-term well-being and resilience of the environment. While scenario 2 is more land-efficient, it presents a possible risk to the overall ecological integrity and liveability of the metropolis by impinging into key biodiversity areas. The study’s cellular automata approach and methodology can be employed for urban planning and biodiversity impact assessment in similar contexts of new city development.

Reclaiming Resilience Through Granular Arbitrage: Anticipating Sea Level Rise in Singapore

ABSTRACT Over the last sixty ears, Singapore has expanded its land footprint over twenty-five percent by reclaiming land from the sea. Its outsized demand for sand to resource these projects has rendered regional sand markets precarious, and successive countries have banned sand exports to Singapore. Nevertheless, the Singapore government has committed to spending $SG one billion (US$ 767 million) a year until 2100 to mitigate sea level rise. While this includes a range of strategies, from improving drainage infrastructure to exploring adaptive solutions, in the main this involves reclaiming vast amounts of land from the sea to act as a bulwark against rising tides. These plans for resilience will be examined through the spectre of Long Island, a proposed project that will act as a barrier against sea level rise and incorporate nature-based solutions that are emblematic of resilience fetishism, all the while obscuring the more foundational element of this resilience, which is sand that will be obtained through granular arbitrage.

From ideal to realistic compact hybrid PV-CSP systems: A technoeconomic evaluation

Compact PV/CSP hybrid systems, based on the integration of both PV and CSP technologies within a single power plant, have been attracting interest in recent years, because of their potential to lower the cost of solar electricity and minimize the land footprint required. However, the objective evaluation of these technologies is complicated by the fact that they involve two separate converters, each delivering a different form of energy (dispatchable for CSP, non-dispatchable for PV). We propose here an original evaluation and optimization approach based on 3 techno-economic indicators quantifying (1) the overall conversion efficiency of these systems compared to their standalone CSP counterparts, (2) the energy production balance between PV and CSP, and (3) the extra manufacturing cost compared to standalone CSP systems. These different indicators are evaluated for two families of hybrid systems (PV Topping and PV Mirror) and for 3 geometries of concentrating optics (Linear Fresnel Lenses, Parabolic Troughs and Solar Towers). One originality of our approach lies in its ability to determine the optoelectronic properties of PV cells likely to lead to the best hybrid performance, taking into account whether or not they are able to reach their own theoretical limits. Another original feature is that the hybrid systems considered in our analysis are compared with CSP equivalents which have been independently optimized. It is shown that the integration of realistic solar cell technologies whose performances deviate significantly from their theoretical limits notably restricts the range of operating conditions for which hybrid systems could outperform their standalone CSP counterparts. We conclude this work by discussing a number of key challenges that need to be overcome in order to develop more competitive and efficient hybrid systems.

Impact of Four Different Chlorella vulgaris Strains on the Properties of Durum Wheat Semolina Pasta

Microalgae are a promising protein source due to their high protein content; high reproductivity; and low carbon, water, and arable land footprints. In this study, the impact of adding 3 and 5% of four Chlorella vulgaris strains, namely Smooth (SCV), Honey (HCV), White (WCV), and New Honey C. vulgaris (NHCV), on the processing, cooking behavior, color, firmness, structure, and sensory properties of durum wheat semolina pasta was investigated. It was hypothesized that (1) changes in physical properties depend on strain and concentration, (2) acceptability varies by strain due to different colors, odors, and flavors, and (3) the absence of fishy odors and flavors is crucial for acceptance rather than color. The results show that high-quality pasta could be produced with all C. vulgaris strains and concentrations. Cooking time and water absorption of all samples decreased but only significantly for the samples with NHCV added. Also, the bite resistance (determined instrumentally and sensorially) increased for almost all samples due to increasing protein and fiber content. A clear concentration dependency could not be found. In terms of sensory acceptance, NHCV performed the best, and an unaltered typical odor was identified to be crucial rather than color or the absence of fishy odor.

A Culturally Acceptable Shift in Diet to Reduce Land Footprint: an Optimization Study for Estonia

A Culturally Acceptable Shift in Diet to Reduce Land Footprint: an Optimization Study for Estonia

Performance Analysis of a Renewable‐Powered Multi‐Gas Floating Storage and Regasification Facility for Ammonia Vessels With Reconversion to Hydrogen

ABSTRACTNatural gas and renewable energy carriers play critical roles in the energy supply chain due to rising energy consumption demands and a significant shift toward cleaner energy. However, the requirement to liquefy and regasify liquefied natural gas (LNG) and renewable energy carriers for transportation makes the entire process expensive and challenging. Hence, a floating storage and regasification unit (FSRU) plant provides a solution to the aforementioned problems with the additional benefit of being more affordable, time‐efficient, and having less land footprint requirement than the conventional onshore facility. The proposed integrated FSRU in this study, is powered by renewable energy, including solar and ocean thermal energy. The subsystems of integrated FSRU consist of parabolic dish collectors (PDC), Rankine cycle, organic Rankine cycle (ORC), multi‐stage flashing (MSF) desalination unit, decomposition, reliquefication, and regasification plants, which provide valuable commodities such as freshwater, electricity, hydrogen, and heating. It can also cater to standard multi‐gas harboring vessels for storage and regasification of sustainable energy carriers. The study assesses the performance of the proposed system thermodynamically by analyzing mass, energy, entropy, and exergy balance equations using the engineering equation solver (EES) software. Furthermore, parametric studies were conducted to understand the interlinkage among various variables. The analytical results show that the proposed system is able to produce 1.82 MW of electricity, 2056 kg/day of fresh water, and 338.3 kg/day of hydrogen, achieving an overall system energy efficiency of 32.7% and exergy efficiency of 79.3%. This approach aims to foster energy diversification, enhance energy security, and support the transition toward sustainable energy systems, as well as further the advancement of maritime transport systems.

Sewage Treatment by Kolkata’s Natural Wetland System

The metropolis of Kolkata stands uniquely positioned to implement a natural sewage treatment paradigm through the utilization of waste stabilization ponds, specifically within the East Kolkata Wetlands (EKW). These shallow oxidation ponds harness solar irradiation and algae bacteria symbiotic processes to effectively treat incoming sewage. Concurrently, nutrient-rich effluents are assimilated through fish production, converting available nutrients into protein—a hallmark of nature-based treatment. A portion of raw sewage is used to cultivate a chunk of vegetables before treatment in fish ponds, and the reclaimed water after treatment is used for vegetable and paddy cultivation downstream. This investigation explains the delineation of a sewage flow system to EKW, a Ramsar-designated site. Substantively, it offers quantitative insights into the sewage volumes and quality undergoing treatment. The sewage flow is higher in the winter months (909.07 MLD) compared to the summer months (709.34 MLD). In general, the sewage from the Kolkata city flowing to the EKW is moderately polluted. Extensive scrutiny of sewage from pond inlets and outlets serves as a quantitative metric for evaluating treatment efficacy. EKW efficiently treats the sewage, demonstrating 59.1% Biological Oxygen Demand (BOD) removal and a 99.28% reduction in fecal coliform. The natural treatment system excels in removing ammoniacal nitrogen (80.38%) and phosphate (90%). The treated water’s quality along the EKW boundary, culminating at the Kulti Gong River discharge point, was systematically assessed. Analytical findings indicate that all measured concentrations in the treated water adhere to prescribed inland surface water discharge standards prescribed by the Central Pollution Control Board, India, barring a marginal elevation in BOD during winter. Evidently, the EKW system adeptly manages substantial sewage volumes, fostering efficient treatment while concurrently facilitating resource recovery through fish production, yielding economic dividends. Despite its substantial land footprint, preserving this inherently sustainable wastewater management paradigm is imperative.

Design of Robust Ballistic Landings on the Secondary of a Binary Asteroid

ESA’s Hera mission aims to visit binary asteroid Didymos in late 2026, investigating its physical characteristics and the result of NASA’s impact by the DART spacecraft in more detail. Two CubeSats onboard Hera plan to perform a ballistic landing on the secondary of the system, called Dimorphos. For these types of landings the translational state during descent is not controlled, reducing the spacecraft’s complexity but also increasing its sensitivity to deployment maneuver errors and dynamic uncertainties. This paper introduces a novel methodology to analyze the effect of these uncertainties on the dynamics of the lander and design a trajectory that is robust against them. This methodology consists of propagating the uncertain state of the lander using the nonintrusive Chebyshev interpolation (NCI) technique, which approximates the uncertain dynamics using a polynomial expansion. The results are then analyzed using the pseudo-diffusion indicator. This indicator is derived from the coefficients of the polynomial expansion, which quantifies the rate of growth of the set of possible states of the spacecraft over time. The indicator is used here to constrain the impact velocity and angle to values that allow for successful settling on the surface. This information is then used to optimize the landing trajectory by applying the NCI technique inside the transcription of the problem. The resulting trajectory increases the robustness of the trajectory compared to a conventional method, improving landing success by 20% and significantly reducing the landing footprint.

Modelling and optimization of concentrated solar power using response surface methodology: A comparative study of air, water, and hybrid cooling techniques

This research introduces a novel approach specifically designed to improve the design of Concentrated Solar Power plants utilizing the Response Surface Methodology. The objective of the suggested methodology is to enhance energy production efficiency by simultaneously minimizing the levelized cost of electricity and the land footprint associated with the power plant while comparing three different cooling techniques: air, water, and hybrid. Two software tools, System Advisor Model and Design-Expert, are employed to validate the primary model, evaluate the responses, generate the predictive models, and verify the results. The configuration of a Concentrated Solar Power plant is influenced by four main factors: the size of the solar field (solar multiple), row spacing, number of solar assemblies per loop, and size of thermal energy storage. In this study, these factors are varied within the following ranges: solar multiple from 1 to 5, row spacing from 10 to 30 m, number of solar assemblies from 4 to 10 per loop, and thermal energy storage from 5 to 15 h. The generated predictive models demonstrated very high accuracy, particularly for the annual energy production, with an error ranging between 0.2% and 1.5%. The findings showed that the hybrid cooling system is the most cost-effective cooling technique and has the highest energy output compared to the evaporative and air-cooling methods. When optimizing the required area of the hybrid cooled plant with a reduction of 47.44%, the analysis indicated a minimal decrease in energy output of 3.61% and a slight increase in the levelized cost of electricity by 0.95%. According to the results, the effect of area on the annual energy production and levelized cost of electricity is significant below the optimal area, while this effect becomes minor at higher values.

Province-specific sustainable diets in China considering nutrition, environment, affordability, and acceptability

Sustainable dietary transition is widely identified essential in addressing the nutrition, environment, and health trilemma. This is particularly important for China, the world's most populous country which is undergoing a rapid dietary structure change. Here, we used a nonlinear optimization algorithm to identify a nutritionally adequate, environmentally friendly, economically affordable, and culturally acceptable diet for each of the 31 provinces in mainland China. We found that province-specific dietary shifts could reduce the carbon, water, land, nitrogen, and phosphorus footprints of China's food consumption by 9.5–25.3%, 10.7–19.1%, 22.4–32.9%, 30.8–40.2%, and 21.4–34.5%, respectively, while meeting the daily recommended intake of essential nutrients and not exceeding current food expenditures. The variation in required food intake was highly province-specific; however, in general, there was a need to reduce the intake of meat, grains, and edible oils and increase the intake of vegetables, fruits, legumes, tubers, and dairy products. Our findings highlight the importance of province-specific diet optimization, which can greatly improve acceptance and feasibility of sustainable dietary transition, guide individuals to change their food consumption behavior, and inform policymakers towards regionally tailored food policies.

Moving towards fully circular insect production: A focus on insect-derived biowastes

Over the last decade, commercialization of insects for food and feed has been exponentially increasing. Insect protein is emerging as a sustainable livestock feed and human food alternative due to its low land and carbon footprint. The principles of insect industry are deeply embedded in the core values of sustainability and circular economy. Black soldier fly (BSF) is the crown jewel of insect industry and is one of the most commercially farmed insects. However, this steadfast growth is accompanied by generation of insect based biowaste such as dead flies and pupae exuviae. This will be a major waste fraction from this industry. This study discusses the valorization potential of this waste into chitin (which finds application in cosmetics, bioplastics, and pesticides, among other industries), biogas, fertilizer, and biochar. There is need to conduct more explorative research on value proposition of insect based biowaste to ensure that this industry can comply fully with circular economy and sustainability principles.

Economic and Environmental Limitations of Sustainable Energy Transition in Europe

In recent decades, the concept of sustainable development has become increasingly widespread since the United Nations Convention on Climate Change was adopted. However, it is also being overused, imitated, politicized, or even ignored. This study analyzes the current conditions and long-term consequences of the European energy transition and discusses the limitations and true economic and environmental implications of implementing energy sustainability. The paper is aimed at forming an understanding of the current environmental conditions and challenges associated with the economic, financial, and environmental consequences of introducing renewables in Europe. Research has revealed that renewables, while cleaner energy sources are not necessarily sustainable as initially suspected. There are various implications and limitations, that is: an initial carbon footprint, land footprint, recycling issues, harmful impacts on wildlife and humans, moreover the efficiency and economic implications when transitioning to a net zero. As a result, it is concluded that the basic principles of the energy transition are to be introduced and considered for it to become indeed sustainable. It is also concluded that when introducing or improving an energy model, it is crucial to consider the country's initial energy and resource base. Nuclear energy should not be disregarded and should considered to be a clean energy source, as well as a safe one, particularly in the context of national security, which is heavily dependent on energy transition.

Does expanding wild venison consumption substitute livestock meat consumption? Evidence from the demand systems analysis of meat products in Hokkaido, Japan

In many countries, growing deer populations cause environmental, economic, and traffic safety problems. This study sheds light on the potential implications of expanding the consumption of venison from hunted wild deer through deer population management efforts. It focuses on changes in environmental impacts resulting from changes in the demand for livestock meat due to increased consumption of wild venison. We analyzed the demand system between them using the Quadratic Almost Ideal Demand System (QUAIDS) model and scanner data from a grocery store chain in Hokkaido Prefecture, Japan. The results show that wild venison is a substitute good for pork and lamb. By contrast, wild venison is a complementary good for imported and domestic beef. Based on the estimated demand system model, we conducted an environmental footprint analysis to estimate the changes in environmental impacts when venison consumption increased. This shows that the greenhouse gas, water, and land footprints would increase, indicating greater environmental impacts, under a scenario of expanded venison consumption. The results demonstrate that increased venison consumption does not necessarily reduce the net environmental impacts of meat consumption, which depends on the demand system for meat products and the environmental footprint intensities of the respective products.

Spatial Differentiation of the Land and Nutrient Footprints for Kampala: Implications for Urban Food Sustainability

Rapid urban growth, together with an increase in urban food demand and rural-urban food flows, effectively transfer the urban footprint to the surrounding cities. In Uganda, where fast urban growth is evident, data on the resultant foodprint is sparse. To bridge this gap in knowledge, this paper quantitatively analyses the flows of the rural-urban cooking banana (matooke) to Kampala, Uganda, and the embedded land and nutrient footprints. Food freight surveys involving interviews with food truck drivers and field measurements were used to obtain data on quantities of banana flow to ten purposively sampled city markets. The results confirm that 88.5% of Kampala’s banana inflows are sourced from the Ankole sub-region. Disaggregation of the flows by season revealed a 52% fall in banana supplies to the city during the wet season. The calculated annual land footprint associated with the city’s banana inflows was 15,268 hectares. The hot spots for NPK nutrient mining are in the Ankole region, including mean daily losses of 362.29±29.13Kg (K), 104.66±8.42Kg (N) and 4.03±0.32Kg(P). The ANOVA results exhibited significant differences (P˂0.05) in the cooking banana land and nutrient footprints between the source regions and concerning the dry and wet seasons, except for the Rwenzori, Kigezi, and Bunyoro sub-regions pertaining to the land footprint and Buganda, Tooro, and Bunyoro as regards the nutrient footprint. These results emphasise the intense rural nutrient mining that is associated with urban food consumption. Thus, to guarantee sustainable matooke production, there is a need to establish waste diversion strategies that enable nutrient recycling back to rural farms.

Multiple environmental and nutritional effects of changing food consumption in urban and rural China

Driven by urbanization and increasing income, dietary changes are dramatic in China. Food consumption directly links environmental and human health, and an in-depth understanding on environment–health nexus is necessary to achieve their co-benefits. Previous studies mostly examine health outcomes through disease risks and premature deaths, overlooking the hidden hunger resulting from inadequate nutrients intakes. Here, we evaluated multiple dietary environmental and nutritional impacts as well as their linkages in urban and rural China for the period 1990–2020. The results showed that daily per capita water, land and carbon footprints are 1.25–1.61 m3, 1.67–2.23 g2, and 1.47–1.84 kg CO2eq. Fat, fiber and Ca were key nutrients influencing dietary nutritional quality. Dietary changes in China increased environmental effects, and increased intakes of both beneficial and restricted-intake nutrients. More importantly, adoption of Chinese Dietary Guidelines, Mediterranean diet, EAT–Lancet, WHO recommendations, and DASH dietary scenarios would increase environmental footprints by 33% and 48% on average compared with current urban and rural diets. It would improve nutritional quality, but increase intakes of restricted-intake nutrients. The complex trade-offs between dietary environmental and nutritional effects emphasize the need for formulating comprehensive dietary guidelines, and food waste reduction is a possible strategy for addressing the environment–health dilemma effectively.

THE CONTRIBUTION OF NATURAL CAPITAL ON CARBON TOTAL FACTOR PRODUCTIVITY IN CHINA

This study focuses on the contribution of natural capital to achieving carbon neutrality in China based on the provincial data from 1998 to 2019. This paper first measures the natural capital of each province by ecological footprint (EF), then explores the contribution of natural capital on carbon total factor productivity (CTFP) through a global non-radial Luenberger productivity indicator (GLPI), and decomposes the new CTFP into efficiency change (EC) and technical change (TC). We find that the contribution of natural capital to CTFP is relatively small, mainly due to the negative impact of infrastructure land and energy footprint and the decline of the marginal effect of natural capital and environmental carrying capacity. Second, technology innovation is still a main driver of promoting the CTFP of EF. Third, the contribution of natural capital to CTFP varies greatly with different types of natural capital and regions. We provide corresponding policy implications based on the main conclusions.

Consumer resistance diminishes environmental gains of dietary change

The environmental gains of dietary change are often assessed in relation to average national diets, overlooking differences in individual consumption habits and people’s willingness to change. This study combines microdata on food intake and consumer behaviour to elicit the likely environmental gains of dietary shifts. We focus on the Netherlands owing to the country’s ambition to halve its dietary footprint by 2050. Linking food recall survey data from a cross-section of the population (n = 4313), life cycle inventory analysis for 220 food products, and behavioural survey data (n = 1233), we estimate the dietary footprints of consumer groups across water, land, biodiversity and greenhouse gas (GHG). We find that meat and dairy significantly contribute to the dietary GHG footprint (59%), land footprint (54%), and biodiversity footprint (59%) of all consumer groups and that male consumers impose a 30%–32% greater burden than women across these impact areas. Our scenario analysis reveals that simply replacing cow milk with soy milk could reduce the GHG, land and biodiversity footprints by ≈8% if widely adopted by the Dutch adult population. These footprints could be further reduced to ≈20% with full adoption of the EAT-Lancet diet but with a significantly increased blue water footprint. However, when incorporating gender- and age-specific willingness to reduce meat and dairy consumption, the environmental gains resulting from partial adoption of the No-Milk diet and EAT diet diminish to a mere ≈0.8% and ≈4.5%, respectively. Consequently, consumer motivation alone is insufficient to realise the significant environmental gains often promised by dietary change. Yet, substituting high-impact food products offers a near-term opportunity to accelerate a rapid sustainable dietary transition. Future studies on sustainable dietary transition must incorporate consumer behaviour to fully comprehend the lock-in of food consumption patterns and targeted policy action required to secure a sustainable food future.

Regional food self-sufficiency potential in the European Alpine space

The sustainability of the food system needs to be improved, including shortening supply chains and promoting the consumption of regional food. Here, we explore the current potential for regional food self-sufficiency in the European Alpine space by calculating the current regional food/feed energy balance, deriving the regional per capita land footprint based on current food/feed consumption rates, and modelling the current potential for regional food/feed self-sufficiency. We show that 59% of the 560 Pcal of energy currently available in the study area comes from domestic production, and almost 60% of the energy is used for livestock consumption, with high regional variability. The resulting land footprints range from 2301 to 2975 m2 cap−1 y−1. Taking into account changes in cropping patterns, partial intensification, but no expansion of agricultural land, the European Alpine space could produce 89% of its current food demand domestically, with high regional variability due to population density, availability of agricultural land, crop yields, climatic conditions and dietary habits. These findings highlight the potential and limitations of regional mountain food systems and call for new strategies to improve sustainability. Reducing the current high consumption of animal products would reduce the land footprint and increase the potential for food self-sufficiency.

Sustainability: An Ethical Challenge: The Overexploitation of the Planet as an Exemplary Case

Earth Overshoot Day is used as an exemplary case to suggest actions to obtain better compliance between the ecological footprints and biocapacities of the world’s regions. This study was based on the Global Footprint Network’s free public data on Earth Overshoot Day. The analyses of the data applied a partial ordering methodology in combination with the so-called Philosophy Model, leading to a joint ranking of the regions based on the simultaneous inclusion of ecological footprint data and data on biocapacities. The ranking was topped by South America, whereas North America and the Middle East/Central Asia were at the bottom of the list. Biocapacity was found to be the most important ranking indicator. Thus, doubling the biocapacity for each region would, on a global scale, lead to a population reserve of approx. 1.5 billion, whereas a halving of the individual ecological footprint would still lead to a population deficit of approximately 1 billion. The footprints and the biocapacities are composed of six and five sub-indicators, respectively, and the carbon footprint together with the built-up land footprint is the most important sub-indicator. To comply with the corresponding available biocapacity, significant reductions in the carbon footprint are needed, close to 50% for high-income countries. The ethical issues, as well as their interconnection with the Sustainable Development Goals, were discussed, with a focus on carbon footprints and well-being, as well as educating women, as illustrative cases.