High Greenhouse Gas Emissions Research Articles

Assessment of carbon footprint of potable water production: A case from Bangladesh

Carbon footprint (CF), a measure of greenhouse gas (GHG) emissions, is currently a global concern because of its significant effects on climate change. Understanding GHG emissions from potable water production is important because water treatment and distribution consume much energy while emitting a significant amount of GHG. With economic and population growth, water demand has increased, resulting in higher GHG emissions. This study aims to assess the CF of potable water production in Bangladesh, focusing on the country’s economic capital, Chattogram. This study estimates and compares the CF of the treatment, distribution, and consumption phases. It also estimates the CF of different water treatment plants (WTPs) during the treatment phase. WTPs use electricity for a full-scale operation, during which approximately 4.5 million m3 of raw water of varying turbidity is treated. This study calculates a country-specific GHG emission factor for Bangladesh’s electricity generation method as different sources produce different quantities of GHGs. This study also considers the energy consumed to distribute water from the WTPs to household rooftop tanks in the distribution phase. For the consumption phase, the study considers the energy consumption for domestic water treatment, which involves boiling of a portion of treated water for drinking purposes. The study estimates that approximately 0.18, 0.27, and 17.52kg CO2-eq are emitted in the treatment, distribution, and consumption phases, respectively, for the production of 1 m3 of water. Boiling at the consumption phase alone generates 97.48 % of the total CF. The daily CFs for surface water and groundwater use in 2017 were 16,387.78 and 34,092.08kg CO2-eq, respectively; those in 2022 were 83,769.25 and 2130.97kg CO2-eq, respectively. The outcome of this study will assist stakeholders and policymakers in the progress of SDG-13 and in effective planning and operational decision making for sustainable water systems.

The fire weather in Europe: large-scale trends towards higher danger

Abstract The climate over Europe has been recorded to be hotter, drier, and more fire-prone over the last decade than ever before, leading to concerns about how climate change will alter fire weather in the future. A typical measure to estimate fire weather severity based on climate is the Canadian fire weather index (FWI). In this study, we used high-resolution, bias-corrected climate model output (∼9 km) from six CMIP6 climate models and four shared socio-economic pathway projections (SSPs) to calculate consistent and comparable daily FWI datasets for Europe from 1950 to 2080. Our study aims to identify regional and large-scale shifts in fire weather severity and its predictability over time to support adaptive planning. We show that irrespective of the future SSP, fire weather will become more severe, but the increase is much stronger under high greenhouse gas emissions. This leads to new areas being exposed to severe fire weather, such as central Europe and rapidly warming mountainous areas. Already fire-prone regions in southern Europe will experience more extreme conditions. We conclude that only the low-emission SSP1-2.6 pathway can prevent strong increases in fire weather beyond the 2050s. Fire surveillance and management will become more important, even in areas and in seasons where they have not been in the focus so far.

Three years of CO2, CH4 and N2O fluxes from different sheepfolds in a semiarid steppe region, China

To better assess greenhouse gas (GHG) emissions from livestock folds in semi-arid steppe zones and reduce uncertainties in regional and national GHG emission inventories, we measured the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from sheepfolds under contrasting management regimes (i.e., summer sheepfolds under continuous and rotational grazing strategies and the winter sheepfold) for 3 consecutive years. Our results showed that these GHG fluxes had high intra-annual and interannual variations, emphasizing the importance of multi-year measurement for achieving temporally representative annual budgets. Sheep presence and temperature appeared to be the key factors driving CH4, CO2 and N2O fluxes from sheepfolds, e.g., higher GHG emissions usually occurred in seasons with sheep presence. However, the sheepfold type exerted a distinct influence on the temperature sensitivity of GHG fluxes, i.e., the Q10 values for GHG fluxes were generally higher in summer sheepfolds than in winter sheepfold. The annual CH4, CO2 and N2O emissions for the 3 sheepfolds were estimated to be 1.5–16.5 kg C ha−1 yr−1 (or 1.9–2.6 g C yr−1sheep−1), 8.6–16.0 t C ha−1 yr−1 (or 5.1–6.6 kg C yr−1sheep−1) and 28.3–41.9 kg N ha−1 yr−1 (or 19.0–26.8 g N yr−1sheep−1), respectively. Averaging across the 3 years, the annual net GHG emissions (CH4 + CO2 + N2O) for all sheepfolds ranged from 47 to 71 t CO2-eq ha−1 yr−1 (or 27–36 kg CO2-eq yr−1 sheep−1), of which CO2 and N2O emissions contributed the most; moreover, the annual net GHG emissions had no significant differences between sheepfold types or grazing strategies. Given that local steppe soils have a lower magnitude of soil respiration (CO2) and N2O emissions and are also net sink for atmospheric CH4, the sheepfold sites in this region are undoubtedly one of the significant hotspots for GHG emissions and could be key areas to focus mitigation action.

Beyond the First Tipping Points of Southern Hemisphere Climate

Analysis of observations, reanalysis, and model simulations, including those using machine learning methods specifically designed for regime identification, has revealed changes in aspects of the Southern Hemisphere (SH) circulation and Australian climate and extremes over the last half-century that indicate transitions to new states. In particular, our analysis shows a dramatic shift in the metastability of the SH climate that occurred in the late 1970s, associated with a large-scale regime transition in the SH atmospheric circulation, with systematic changes in the subtropical jet, blocking, zonal winds, and storm tracks. Analysis via nonstationary clustering reveals a regime shift coincident with a sharp transition to warmer oceanic sea surface temperatures and increased baroclinicity in the large scales of the Antarctic Circumpolar Circulation (ACC), extending across the whole hemisphere. At the same time, the background state of the tropical Pacific thermocline shoaled, leading to an increased likelihood of El Niño events. The SH climate shift in the late 1970s is the first hemispheric regime shift that can be directly attributed to anthropogenic climate change. These changes in dynamics are associated with additional regional tipping points, including reductions in mean and extreme rainfall in south-west Western Australia (SWWA) and streamflow into Perth dams, and also with increases in mean and extreme rainfall over northern Australia since the late 1970s. The drying of south-eastern Australia (SEA) occurred against a background of accelerating increases in average and extreme temperatures across the whole continent since the 1990s, implying further inflection points may have occurred. Analysis of climate model simulations capturing the essence of these observed shifts indicates that these systematic changes will continue into the late 21st century under high greenhouse gas emission scenarios. Here, we review two decades of work, revealing for the first time that tipping points characteristic of regime transitions are inferred to have already occurred in the SH climate system.

Evaluation of a novel palm-free fat supplement to reduce the carbon footprint of diets for dairy cows

Most fat supplements added to dairy diets are derived from palm acid oil or palm fatty acid distillate. There are environmental concerns about palm oil production due to deforestation and high greenhouse gas (GHG) emissions. The objective of this study was to evaluate a palm-free fat supplement, Envirolac. Envirolac contains vegetable oils, marine oils and glycerine encapsulated within a cellulosic fibre-clay mineral carrier matrix. The carrier matrix has small particle size to facilitate rapid rumen passage and minimal interference with rumen digestion. Fifty cows were divided into two balanced groups of 25 cows. Each group received Control (calcium soap of palm fatty acid distilate, 0.5 kg/d) and Envirolac (0.5 kg/d) diets in a crossover design with two feeding periods of four weeks duration, so that each cow received both diets. Envirolac has a lower total fat concentration than the calcium soap, so the feeding rate delivered less total fat. When fed on Envirolac, cows yielded more milk 40.7 v 40.1 kg/d), energy-corrected milk (ECM; 42.9 v 41.3 kg/d) and milk components (1605 v 1514 g fat, 1239 v 1199 g protein, 1871 v 1839 g lactose, per day), and produced milk with higher concentrations of fat (40.1 v 38.6 g/kg) and protein (30.7 v 30.1 g/kg), than when fed on Control. When fed on Envirolac, cows produced milk with higher concentrations of fatty acids (FA) synthesised de novo in the mammary gland (25.5 v 23.6 g/100 g total FA), lower concentration of palmitic acid (35.5 v 37.2 g/100 g total FA), and higher concentrations of some long-chain fatty acids (C20:0, C20:1, C20:3n3, C21:0, C22:0, C22:6n3 and C23:0), than when fed on Control. There was no effect of treatment on dry matter intake (DMI; mean 23.4 kg/d), so feed efficiency was higher (1.83 v 1.76 kg ECM/kg DMI) for Envirolac than Control. There was no effect of treatment on dry matter digestibility (0.73), methane production (433 g/d), methane yield (19.3 g/kg DMI) or methane intensity (10.9 g/kg ECM). Feed carbon footprint of Envirolac was calculated to be 1028 g CO2eq/kg DM, which is 0.46 of the value for a calcium soap (2830 g CO2eq/kg DM), and reduced feed carbon footprint per kg ECM milk production by 11 %. This study demonstrates that Envirolac can replace palm-based fat supplements in dairy diets to improve feed efficiency and reduce the carbon footprint of milk production.

Exceptional atmospheric conditions in June 2023 generated a northwest European marine heatwave which contributed to breaking land temperature records

The Northwest European shelf experienced unprecedented surface temperature anomalies in June 2023 (anomalies up to 5 °C locally, north of Ireland). Here, we show the shelf average underwent its longest recorded category II marine heatwave (16 days). With state-of-the-art observation and modelling capabilities, we show the marine heatwave developed quickly due to strong atmospheric forcing (high level of sunshine, weak winds, tropical air) and weak wave activity under anticyclonic weather regimes. Once formed, this shallow marine heatwave fed back on the weather: over the sea it reduced cloud cover and over land it contributed to breaking June mean temperature records and to enhanced convective rainfall through stronger, warmer and moister sea breezes. This marine heatwave was intensified by the last 20-year warming trend in sea surface temperatures. Such sea surface temperatures are projected to become commonplace by the middle of the century under a high greenhouse gas emission scenario.

Behavioural determinants of healthy and environmentally friendly diets in French university students

Although encouraging the shift toward sustainable diets in young adults is a major challenge to preserve population and planet health, the precursors of sustainable diets in this population remain unknown. This study aimed to identify the behavioural determinants of healthier and more environmentally friendly diets among university students. A sample of 582 French university students reported their food consumption using an online 125-item food frequency questionnaire. The nutritional quality (adherence to French recommendations, sPNNS-GS2) and the greenhouse gas emissions (GHGE) of students' diets were calculated for an isocaloric diet. Behavioural determinants were measured based on a literature review and classified into the Capability, Opportunity, Motivation Behaviour (COM-B) framework. Linear models, adjusted for socioeconomic characteristics, were run to identify the most prominent behavioural predictors of nutritional quality and GHGE of students’ diets. Higher cooking skills (β = 0.38, p = 0.01) and health motives (β = 0.91, p < 0.001) were associated with higher nutritional quality. Greater environmental knowledge was linked to lower GHGE (β = −0.07, p = 0.002), while health and weight control motives were associated with higher GHGE (β = 0.26, p = 0.02 and β = 0.39, p < 0.001). Enhancing cooking skills and environmental knowledge could enable healthy and environmentally friendly diets, but health-based motives can act as a lever and as a barrier.

Environmentally friendly splints for limb immobilisation: a systematic review.

Climate change is estimated to be the biggest global health threat of the 21st century, and has prompted calls to move away from processes in healthcare associated with high energy consumption and greenhouse gas emission. In musculoskeletal medicine, splints are widely used for limb immobilisation. These have typically been made from single-use materials such as gypsum, although in recent years purportedly environmentally friendly splints have been designed. In this systematic review, we set out to assess the clinical effectiveness of all commercially available environmentally friendly splinting materials, including Woodcast®. The AMED (Allied and Complementary Medicine Database), CINAHL® (Cumulative Index to Nursing and Allied Health Literature), Cochrane Central Register of Controlled Trials, Embase®, Emcare® and MEDLINE® databases were searched to identify studies assessing the clinical effectiveness of biodegradable and environmentally friendly splints prior to paper review and data extraction. Formal quantitative synthesis was not possible owing to the substantial heterogeneity in the study designs and outcome measures. Six papers met the inclusion criteria, all investigating one particular splint material (Woodcast®). One was a case series, two were cohort studies and three were randomised controlled trials. Primary outcome measures were heterogeneous but the environmentally friendly splints were generally equivalent to traditional splint materials. Studies were mostly at a high risk of bias. There is limited research assessing 'green' splints in practice although the data suggest similarity with existing materials and no substantial safety concerns. Further scrutiny of the clinical effectiveness and environmental credentials of such splints is also required.

The productivity paradox in carbon‐intensive companies: How eco‐innovation affects corporate environmental and financial performance

AbstractEmpirical studies analyzing the relationship between strategies to reduce greenhouse gas (GHG) emissions and firms' environmental and financial performance often fail to find significant effects when firms invest in innovative green technologies. Indeed, as efficiency and productivity gains of new technologies can often be reaped only after a certain time gap, cross‐sectional studies are bound to ignore the time component, thus becoming subject to the productivity paradox. Employing an integrative approach, drawing on eco‐efficiency theory, productivity paradox, and innovation diffusion principles, this longitudinal study observes companies with high GHG emissions during and after the first two European Union Emission Trading Scheme (EU ETS) trading periods (2005–2019). It analyzes (1) the dynamics of carbon reduction practices over time, (2) the impact of GHG reduction strategies on environmental performance, (3) the positive effect of GHG‐related efficiency improvements on firm performance, while considering (4) the moderating effect of GHG emissions type on the latter relationship.

Impacts of Climate Change on the Ascension Island Marine Protected Area and Its Ecosystem Services

AbstractThis is the first projection of marine circulation and biogeochemistry for the Ascension Island Marine Protected Area (AIMPA). Marine Protected Areas are a key management tool used to safeguard biodiversity, but their efficacy is increasingly threatened by climate change. To assess an MPA's vulnerability to climate change and predict biological responses, we must first project how the local marine environment will change. We present the projections of an ensemble from the Sixth Coupled Model Intercomparision Project. Relative to the recent past (2000–2010), the multi‐model means of the mid‐century (2040–2050) project that the AIMPA will become warmer (+0.9 to +1.2°C), more saline (+0.01 to +0.10), with a shallower mixed layer depth (−1.3 to −0.8 m), a weaker Atlantic Equatorial Undercurrent (AEU) (−1.5 to −0.4 Sv), more acidic (−0.10 to −0.07), with lower surface nutrient concentrations (−0.023 to −0.0141 mmol N m−3 and −0.013 to −0.009 mmol P m−3), less chlorophyll (−6 to −3 µg m−3) and less primary production (−0.31 to −0.20 mol m−2 yr−1). These changes are often more extreme in the scenarios with higher greenhouse gases emissions and more significant climate change. Using the multi‐model mean for two scenarios in the years 2090–2100, we assessed how five key ecosystem services in both the shallow subtidal and the pelagic zone were likely to be impacted by climate change. Both low and high emission scenarios project significant changes to the AIMPA, and it is likely that the provision of several ecosystem services will be negatively impacted.

Emerging technologies in the fight against climate change

Climate change is directly related to global warming. Such warming is caused by high greenhouse gases emissions into the atmosphere due to anthropogenic activities. Because of this, there is a greater incidence of health problems in the population, not to mention the damage to the environment. There has been increasing debate and discussion about ways to reduce greenhouse gas emissions as a way of mitigating climate change. Given this, information and communication technologies are an important factor that can bring benefits and gains to the reduction and/or monitoring of these gases. Therefore, the current work aimed to identify information and communication technologies (ICTs) for monitoring industrial atmospheric emissions that contribute to the increase in climate change. Regarding the research methodology, it is a applied research, has a qualitative approach and in terms of its objective, it is characterized as exploratory. Regarding the results, it was proven through practical examples in companies that it is possible to use ICTs to minimize and/or mitigate the emission of atmospheric pollutants. Therefore, it is concluded that technologies can combat the causes of climate change within companies and even smart cities.

Conventional activated sludge vs. photo-sequencing batch reactor for enhanced nitrogen removal in municipal wastewater: Microalgal-bacterial consortium and pathogenic load insights

Municipal wastewater treatment plants are mostly based on traditional activated sludge (AS) processes. These systems are characterised by major drawbacks: high energy consumption, large amount of excess sludge and high greenhouse gases emissions. Treatment through microalgal-bacterial consortia (MBC) is an alternative and promising solution thanks to lower energy consumption and emissions, biomass production and water sanitation. Here, microbial difference between a traditional anaerobic sludge (AS) and a consortium-based system (photo-sequencing batch reactor (PSBR)) with the same wastewater inlet were characterised through shotgun metagenomics. Stable nitrification was achieved in the PSBR ensuring ammonium removal > 95 % and significant total nitrogen removal thanks to larger flocs enhancing denitrification. The new system showed enhanced pathogen removal, a higher abundance of photosynthetic and denitrifying microorganisms with a reduced emissions potential identifying this novel PSBR as an effective alternative to AS.

Climate Change Impact on the Distribution of Forest Species in the Brazilian Amazon

Studies using ecological niche models highlight the vulnerability of forest species to climate change. This work aimed to analyze the distribution of timber species Aspidosperma desmanthum, Cariniana micranta, Clarisia racemosa, Couratari oblongifolia, and Vouchysia guianensis, which are targets of deforestation, to predict the impacts of climate change and identify areas for their conservation in the Amazon. For this purpose, 37 environmental variables were used, including climatic and edaphic factors. The models were fitted using five algorithms, and their performance was evaluated by the metrics Area Under the Curve (AUC), True Skill Statistic, and Sorensen Index. The deforestation analysis was conducted using data accumulated over a period of 14 years. The study indicated that under the most pessimistic predictions, considering continued high emissions of greenhouse gases (GHGs) from the use of fossil fuels, SSP5–8.5, potential habitat loss for the studied species was more significant. Analyses of the species show that the Western Amazon has a greater climatic suitability area for the conservation of its genetic resources. Further study of the accumulated deforestation over 14 years showed a reduction in area for all species. Therefore, in situ conservation policies and deforestation reduction are recommended for the perpetuation of the analyzed forest species.

Comparison of Greenhouse Gas Emissions, Nitrogen Intensity, Gross Margin, and Land Use Occupation between Comparable Conventional and Organic Managed Dairy Farms

In this study, 200 Norwegian dairy farms were analyzed over three years to compare greenhouse gas emissions, nitrogen (N) intensity, gross margin, and land use occupation between organically and conventionally managed farms. Conventionally managed farm groups were constructed based on propensity matching, selecting the closest counterparts to organically managed farms (n=15). These groups, each containing 15 farms, were differentiated by an increasing number of matching variables. The first group was matched based on geographical location, milk quota, and milking cow units. In the second match, the proportion of milking cows in the total cattle herd was added, and in the third, the ratio of milk delivered to milk produced and concentrate usage per dairy cow were included. The analysis showed that the conventionally managed farms (n=185) had higher greenhouse gas emissions (1.42 vs 0.98 kg CO2 per 2.78 MJ of edible energy from milk and meat, calculated as GWP100-AR4) and higher N intensity (6.9 vs 5.0 kg N input per kg N output) compared to the organic farms (N=15). When comparing emissions per kg of energy-corrected milk (ECM) delivered, conventional farms also emitted more CO2 (1.07 vs 0.8 kg CO2 per kg ECM). Furthermore, conventionally managed farms showed lower gross margins both in terms of NOK per 2.78 MJ edible energy delivered (5.8 vs 6.5 NOK) and per milking cow unit (30 100 vs 34 400 NOK), and they used less land (2.9 vs 3.6 m² per 2.78 MJ edible energy delivered) compared to organic farms. No differences were observed among the three conventionally managed groups in terms of emissions, N intensity, land use occupation, and gross margin.

Quantifying the greenhouse gas emissions of New Zealand households’ food purchases: An analysis by sociodemographic variables

New Zealand has committed to a 50% reduction in greenhouse gas emissions (GHGEs) from 2005 levels by 2030. Dietary changes within New Zealand could simultaneously improve population health and contribute towards the nation’s emissions reduction target, as agricultural emissions are estimated to account for half of New Zealand’s GHGEs(1). This research aimed to quantify the GHGEs associated with household purchases of major food groups in New Zealand and identify the sociodemographic characteristics that are associated with per capita household dietary emissions. Household dietary emissions were estimated using the NielsenIQ Homescan(R) consumer panel — a large sample of households within New Zealand who report purchasing data of take-home food and beverages. The sample is nationally representative in terms of broad geographical regions and selected key demographic characteristics. Carbon emission estimates were assigned to 1,908,485 total food and beverage purchases from 1,775 households over one year (2019) using a process-based life cycle assessment (LCA) dataset initially constructed in the United Kingdom (UK) and adapted for New Zealand(2). This LCA dataset contains estimates of greenhouse gas emissions generated over the life cycle of the production of food products from the following stages: farming and processing, transit packaging, consumer packaging, transport, warehouse and distribution, refrigeration, and overheads. Greenhouse gas emissions are expressed in kg of carbon dioxide equivalents per kg of food product over a 100-year time horizon. Total emissions from purchases of major food groups were then estimated. Multiple linear regression was used to examine the relationships between household variables and per capita dietary emissions. Overall purchases of red and processed meat (35%) and dairy products (19%) were responsible for the greatest proportion of emissions. The age group of the primary household shopper as well as household size were predictors of per capita dietary emissions — households with primary shoppers &gt; 65 years had, on average, 33% (95% CI: 20% to 49%) higher per capita dietary emissions, compared to households with primary shoppers 34 years; and every additional household member was associated with, on average, 11% (95% CI: 9% to 13%) lower per capita dietary emissions. We have shown in this large representative sample of New Zealand households that purchases of just two food groups — red and processed meat, and dairy — were responsible for approximately half of dietary greenhouse gas emissions. Larger households had lower per capita dietary greenhouse gas emissions, and older shoppers had relatively higher greenhouse gas emissions. Whilst similar associations have been reported elsewhere more research is needed to confirm these latter findings. With enhanced understanding of the observed association between age of a household’s primary shopper and per capita dietary emissions, interventions may be devised that encourage shoppers to purchase lower-emitting foods, particularly less meat and dairy.

Resource Intensity Analysis of Producing 21 Types of Plastic in Terms of Mining Activity

Material flow analysis of plastics has attracted considerable attention for achieving sustainable production and consumption. However, the direct weights of each plastic have been analyzed alone, not considering the amount of natural resources as inputs for plastic production. Therefore, we analyzed the cradle-to-gate resource intensity of 21 types of plastics in terms of mining activity, using the total material requirement under the life cycle concept. It was found that the resource use for plastic production differs by up to approximately 10 times depending on the plastic type. By applying these findings to the material flow analysis of some countries and regions, we found that the quantity of natural resources was more than 20 times the original weight attributed to plastic production. By comparing resource use with greenhouse gas emissions, plastics with higher greenhouse gas emissions were found to have higher resource use, indicating a positive correlation, whereas the opposite trend was also found for some plastics. Considering plastic alternatives, we found that the quantity of natural resources in plastic-based shopping bags is nearly equivalent to that in paper-based bags, whereas that in plastic-based straws is greater than that in paper-based bags. Focusing only on the direct weight of plastic may mislead the decision-making process.

Climate sustainability through a dynamic duo: Green hydrogen and crypto driving energy transition and decarbonization

Climate change persists as a pressing global issue due to high greenhouse gas emissions from fossil fuel-based energy sources. A transition to a greener energy matrix combined with carbon offsetting is imperative to mitigate the rate at which global temperature ascends. While countries have deployed faith in green hydrogen to accelerate worldwide decarbonization efforts, the concurrent rise of blockchain-operated crypto-applications, such as bitcoin, has exacerbated climate change concerns. In this study, we propose technological solutions that combine the green hydrogen infrastructure with bitcoin mining operations to catalyze environmental and socioeconomic sustainability in climate change mitigation strategies. Since the present state of crypto-operations undeniably contributes to worldwide carbon emissions, it becomes vital to explore opportunities for harnessing the widespread enthusiasm for bitcoin as an aid toward a sustainable and climate-friendly future. Our findings reveal that green hydrogen production, paired with crypto-operations, can accelerate the deployment of solar and wind power capacities to boost conventional mitigation frameworks. Specifically, leveraging the economic potential derived from green hydrogen and bitcoin for incremental investment in renewable energy penetration, this dynamic duo can enable capacity expansions of up to 25.5% and 73.2% for solar and wind power installations. Therefore, the proposed technological solutions that leverage green hydrogen and bitcoin mining, bolstered with appropriate policy interventions, can not only strengthen renewable power generation and carbon offsetting capacities but also contribute significantly to achieving climate sustainability.

Identifying standard and simple designs of Power-to-Methanol processes: The costs of complexity reduction

First industrial-scale Power-to-Methanol plants are starting to be deployed in various geographic locations to tackle the problem of high greenhouse gas emissions of the predominantly fossil-based production of methanol. With the aim to speed up the deployment by streamlining their engineering and construction, we explore the potential of reducing the complexity of designs to be distributed across locations with different renewable energy conditions. A multi-objective optimization-based method incorporating a broad process network for early-stage process synthesis is proposed, which by determining the installed capacities of technologies from the chemical production, utility and storage subsystems, identifies alternative designs with different levels of complexity along two dimensions: 1) the number of different technologies used, 2) standardization of designs across different locations. The method was applied to case studies, which paired together design locations with either wind- or solar-dominant renewable resource conditions in the US and Chile for standardization. As per the method, the increases of methanol production costs due to reduced design flexibility, inherently bound to complexity reduction, were quantified and Pareto fronts were constructed. These uncovered the possibility to significantly reduce the complexity of the designs with only small increases of the production costs. By comparing the results of the case studies under different cost and operation scenarios, we characterized general aspects, which need to be considered for such design simplification. One of the main outcomes were the quantified cost-increases due to standardization, which were around 7 and 15 % relative to the specifically designed plants for each location in the US and Chile case studies respectively. A subsequent analysis of the economies of numbers through learning rates reported in academic literature suggested that the proposed standardization, even across extremely different locations, could compensate these cost-increases and be economically beneficial. Yet, more specific data on achievable cost-reductions are needed, requiring more interaction with the industry and further research, for which we highlighted promising directions.

Comparing the whole life cycle carbon impact of conventional and biogenic building materials across major residential typologies in Ghana and Senegal

Across West African built environments, patterns of high greenhouse gas emissions are driven by the widespread importation of high embodied carbon building materials by a largely self-built industry and recurring operational carbon costs driven by increased access to fossil-fuel based energy services. Using a whole life cycle assessment (LCA) of major residential typologies in two case-study West African countries, Ghana and Senegal, this paper compares the greenhouse gas emissions of imported building materials with local alternative biogenic and geogenic materials within conventional housing typologies. Results indicated that locally sourced biogenic and geogenic materials may be rendered ineffective in buildings if future typologies do not address the effective space density, passive design strategies and increased renewable energy-use. For the building typology with the highest carbon footprint, the Ghanaian detached house, the substitution of conventional building materials with non-fired earth masonry did not have any significant impact. As shown in the housing typology with the lowest operational to embodied carbon ratio, the Senegalese vertical housing case study, optimizing the thermal mass design of earthen building envelopes can significantly drive down lifetime operational carbon emissions. For tropical low-rise building typologies dominated by high roof area to building volume ratios, roof insulation could drive down operational carbon of the building by a factor of 4 to 5. Although each additional storey results in approximately 10–12 % increase in greenhouse gas emissions, the vertical expansion of housing represents an important driver in reducing greenhouse gas emissions per capita.

Plastic film mulching increases crop yields and reduces global warming potential under future climate change

Identifying suitable cropping systems and planting areas with high yields and low greenhouse gas (GHG) emissions to adapt to climate change is essential for sustainable agricultural development. The DeNitrification-DeComposition (DNDC) model and the Coupled Model Inter-comparison Project Phase 6 (CMIP6) dataset were used to evaluate the impact of climate scenarios on the crop yields and global warming potential (GWP) of maize, winter wheat, and potato under plastic film mulching (PM) and without mulching (CK) systems on the Loess Plateau for 2020–2100. The result showed that the DNDC model could simulate crop yields and carbon dioxide, nitrous oxide, and methane emissions (adjusted R2 > 0.55, normalized root mean square error (nRMSE) < 0.32). Under multiple emission scenarios, the yields of maize and winter wheat increased linearly with time (p < 0.05), the GWP decreased linearly with time (p < 0.05), and the coefficients of variation of both were lower for the PM than CK, indicating that the impact of future climate change on PM system was small and can achieve synergy between food security and carbon reduction. The results of regional divergence characteristics suggested that areas with precipitation below 400 mm were suitable for maize cultivation, especially the PM system, while areas with precipitation above 400 mm were suitable for winter wheat cultivation – both of which could achieve the goals of high yield and low GHG emissions. This study presents an overview of spatiotemporal changes in production and ecological effects, providing a basis for developing agricultural management practices and cultivation areas to address climate change, and could promote the development of dryland agroecosystems in China in a green and sustainable direction.