Building stock growth around the world drives extensive material consumption and environmental impacts. Future impacts will be dependent on the level and rate of socioeconomic development, along... Show moreBuilding stock growth around the world drives extensive material consumption and environmental impacts. Future impacts will be dependent on the level and rate of socioeconomic development, along with material use and supply strategies. Here we evaluate material-related greenhouse gas (GHG) emissions for residential and commercial buildings along with their reduction potentials in 26 global regions by 2060. For a middle-of-the-road baseline scenario, building material-related emissions see an increase of 3.5 to 4.6 Gt CO2eq yr-1 between 2020-2060. Low- and lower-middle-income regions see rapid emission increase from 750 Mt (22% globally) in 2020 and 2.4 Gt (51%) in 2060, while higher-income regions shrink in both absolute and relative terms. Implementing several material efficiency strategies together in a High Efficiency (HE) scenario could almost half the baseline emissions. Yet, even in this scenario, the building material sector would require double its current proportional share of emissions to meet a 1.5 degrees C-compatible target.Building construction causes large material-related emissions which present a serious decarbonization challenge. Here, the authors show that the building material sector could halve emissions by increasing efficiency until 2060 but even then its emissions would be twice as high as needed to meet the 1.5 degrees C target. Show less
Zhong, X.; Hu, M.; Deetman, S.P.; Dias Rodrigues, J.F.; Lin, H.; Tukker, A.; Behrens, P.A. 2021
Energy efficiency plays an essential role in energy conservation and emissions mitigation efforts in the building sector. This is especially important considering that the global building stock is... Show moreEnergy efficiency plays an essential role in energy conservation and emissions mitigation efforts in the building sector. This is especially important considering that the global building stock is expected to rapidly expand in the years to come. In this study, a global-scale modeling framework is developed to analyze the evolution of building energy intensity per floor area during 1971-2014, its relationship with economic development, and its future role in energy savings across 21 world regions by 2060. Results show that, for residential buildings, while most high-income and upper-middle-income regions see decreasing energy intensities and strong decoupling from economic development, the potential for further efficiency improvement is limited in the absence of significant socioeconomic and technological shifts. Lower-middle-income regions, often overlooked in analyses, will see large potential future residential energy savings from energy intensity reductions. Harnessing this potential will include, among other policies, stricter building efficiency standards in new construction. For the commercial sector, during 1971-2014, the energy intensity was reduced by 50% in high-income regions but increased by 193% and 44% in upper-middle and lower-middle-income regions, respectively. Given the large energy intensity reduction potential and rapid floor area growth, commercial buildings are increasingly important for energy saving in the future. (C) 2021 The Author(s). Published by Elsevier Ltd. Show less
Musters, C.J.M.; Evans, T.R.; Wiggers, J.M.R.; Zelfde, M. van 't; Snoo, G.R. de 2021
Forty years of Leiden environmental sciences relates the story of CML, today one of the Faculty of Science’s eight institutes but with its roots in a more or less in dependent group of ex-activists... Show moreForty years of Leiden environmental sciences relates the story of CML, today one of the Faculty of Science’s eight institutes but with its roots in a more or less in dependent group of ex-activists within the university. Back in the day, many of those at the top of the university would probably have had trouble accepting that ‘those upstarts’ would still be around forty years on – not locked away in some cubbyhole with their stencil duplicator, but as a professor, assistant professor or even a dean. Today they are professors emeritus or have retired: Helias Udo de Haes, Wouter de Groot, Gerard Barendse, Gjalt Huppes, Gerard Persoon, Hans de Iongh and Jan Boersema – which doesn’t stop most of them just carrying on working. And a new generation of environmental scientists is now leading CML’s research and teaching: Geert de Snoo, Arnold Tukker, Martina Vijver, Peter van Bodegom, Jeroen Guinée, Ester van der Voet and René Kleijn. Show less
Yirga, G.; Leirs, H.C.; Iongh, H.H. de; Asmelash, T.; Gebrehiwot, K.; Vos, M.; Bauer, H. 2017
We report densities of spotted hyaena (Crocuta crocuta) and African golden wolf (Canis anthus) in Enderta district in northern Ethiopia with high human and low natural prey densities. We estimated... Show moreWe report densities of spotted hyaena (Crocuta crocuta) and African golden wolf (Canis anthus) in Enderta district in northern Ethiopia with high human and low natural prey densities. We estimated spotted hyaena and African golden wolf abundance and characterized their spatial distribution with three methods we surveyed four road-transects for 66 nights during dry (n = 41) and wet (n = 25) seasons, we used 34 calling stations and we mapped all active spotted hyaena dens at the time of the survey. The density of spotted hyaena and African golden wolf increased with proximity to towns where human density was higher. A total of 562 spotted hyaena and 63 African golden wolf responded to calling stations, leading to estimates of 1145 spotted hyaena and 166 African golden wolf in Enderta district. This method also found a significantly higher spotted hyaena and African golden wolf abundance in high human density areas. Maximum response radius was 2.8 km for spotted hyaena and 2.5 km for African golden wolf, and response probability was 0.83 for spotted hyaena and 0.8 for African golden wolf, respectively. We found 40 active spotted hyaena dens with 1507 remnants of prey, and the majority of the dens were located close to rivers and villages. Our findings show a positive relationship between spotted hyaena, African golden wolf and human concentrations that might demonstrate a case of exceptional coexistence of humans and carnivores, both at high densities. We suggest further investigations into co-adaptations between humans and predators in the study area. Show less
The aim of this thesis was to investigate vegetation management within the agricultural landscape and determine at which scale and which practices are most beneficial to invertebrate... Show moreThe aim of this thesis was to investigate vegetation management within the agricultural landscape and determine at which scale and which practices are most beneficial to invertebrate assemblages and the associated food web. We determined invertebrate abundance, species richness, and diversity using sticky boards, sweep netting, and pitfall traps to sample. Our examination ranged from the field level to the landscape level of 6000 m. Practices examined include mowing, prairie restoration, and summer fire. Management recommendations are made based on the results of our research. Show less
Small scale farming systems in the Western Highlands of Cameroon (WHC) are influenced by many factors. Understanding the determinants that influence the system is essential when targeting... Show moreSmall scale farming systems in the Western Highlands of Cameroon (WHC) are influenced by many factors. Understanding the determinants that influence the system is essential when targeting appropriate intervention strategies for improvement. A field survey was carried out and analysed to understand the forces that drive the farming systems in this area. The impacts of farming practices on farm sustainability were used as indicators to score sustainability. The results revealed that the household characteristics were very similar across the villages while the sustainability differed depending on the intensity of off-farm inputs in the production systems and other socio-economic factors. Sustainability had significant negative relationships with the intensity of land use, off-farm inputs, and sole cropping practice and a positive relationship with the age of the head of the household. The determinants of the system which explained 62.15% of the total variation of sustainability in the study area were grouped to indicate a number of underlying common factors influencing sustainability. The villages of the WHC had much in common and could benefit equally from the same improved technologies and recommendations. Show less
There are only a limited number of studies that have developed appropriate models which incorporate bioavailability to estimate mixture toxicity. Here, we explored the applicability of the extended... Show moreThere are only a limited number of studies that have developed appropriate models which incorporate bioavailability to estimate mixture toxicity. Here, we explored the applicability of the extended biotic ligand model (BLM) and the WHAM-F tox approach for predicting and interpreting mixture toxicity, with the assumption that interactions between metal ions obey the BLM theory. Seedlings of lettuce Lactuca sativa were exposed to metal mixtures (Cu-Ni, Cu-Cd, and Ni-Cd) contained in hydroponic solutions for 4 days. Inhibition to root elongation was the endpoint used to quantify the toxic response. Assuming that metal ions compete with each other for binding at a single biotic ligand, the extended BLM succeeded in predicting toxicity of three mixtures to lettuce, with more than 82 % of toxicity variation explained. There were no significant differences in the values of f mix50 (i.e., the overall amounts of metal ions bound to the biotic ligand inducing 50 % effect) for the three mixture combinations, showing the possibility of extrapolating these values to other binary metal combinations. The WHAM-F tox approach showed a similar level of precision in estimating mixture toxicity while requiring fewer parameters than the BLM-f mix model. External validation of the WHAM-F tox approach using literature data showed its applicability for other species and other mixtures. The WHAM-F tox model is suitable for delineating mixture effects where the extended BLM also applies. Therefore, in case of lower data availability, we recommend the lower parameterized WHAM-F tox as an effective approach to incorporate bioavailability in quantifying mixture toxicity. Show less
In 2010, Chinese export restrictions caused the price of the rare earth element neodymium to increase by a factor of 10, only to return to almost normal levels in the following months. This despite... Show moreIn 2010, Chinese export restrictions caused the price of the rare earth element neodymium to increase by a factor of 10, only to return to almost normal levels in the following months. This despite the fact that the restrictions were not lifted. The significant price peak shows that this material supply chain was only weakly resistant to a major supply disruption. However, the fact that prices rapidly returned to lower levels implies a certain resilience. With the help of a novel approach, based on resilience theory combined with a material flow analysis (MFA) based representation of the neodymium magnet (NdFeB) supply chain, we show that supply chain resilience is composed of various mechanisms, including (a) resistance, (b) rapidity, and (c) flexibility, that originate from different parts of the supply chain. We make recommendations to improve the capacity of the NdFeB system to deal with future disruptions and discuss potential generalities for the resilience of other material supply chains. Show less
Context: Livestock depredation and scavenging of waste by the spotted hyena (Crocuta crocuta) occurs widely across Ethiopia. Aims: The aim of this study was to investigate the food base of the... Show moreContext: Livestock depredation and scavenging of waste by the spotted hyena (Crocuta crocuta) occurs widely across Ethiopia. Aims: The aim of this study was to investigate the food base of the spotted hyena and livestock depredation across Ethiopia. Methods: The diet of spotted hyenas was assessed in 17 randomly selected study sites across the country, including two national parks, by scat analysis. We conducted an extensive survey of livestock depredation and economic impact in 10 randomly selected subdistricts using semistructured interviews with 3080 randomly selected households. Key results: We found that even spotted hyenas from national parks feed predominantly on anthropogenic waste. Households reported losses of 2230 domestic animals, 3.9% of their stock or an average annual financial loss of US$10.3 per household over the past five years. The diet of spotted hyenas showed only prey items of domestic origin except in Chebera Churchura National Park, where a few items of prey of wild species were found. Frequencies of prey remains of cattle, sheep, donkey and goat were highest in decreasing order. Key conclusions: Survival of hyenas in Ethiopia is thus largely and widely dependent on management of livestock conflict and waste. Some hairs in scats originated from depredation, but most food intake is from waste dumps and slaughterhouses. Implications: Waste management, spotted hyena persistence and environmental sanitation area are linked. Show less
Metals in soils can pose a serious threat to soil dwelling organisms, plants, and human beings. A major uncertainty in terrestrial ecological risk assessment for metals is theintegrated effect of... Show moreMetals in soils can pose a serious threat to soil dwelling organisms, plants, and human beings. A major uncertainty in terrestrial ecological risk assessment for metals is theintegrated effect of the physicochemical properties of soil on toxicity and how this allows for extrapolation of toxicity data across soils. The recognition that soil type is an important factor that determines metal toxicity, goes along with the increasing insight into bioavailability. There is a growing consensus that only a proportion of the total amount of metal in soil isavailable for uptake by organisms and subsequently induces toxic effects. Development of mechanistically underpinned approaches for explaining and predicting availability effects onmetal toxicity has been the subject of many research efforts in terrestrial ecotoxicology. Show less
Trimbos, K.B.; Doorenweerd, C.; Kraaijeveld, K.; Musters, C.J.M.; Groen, N.M.; Kniff, P. de; ... ; Snoo, G.R. de 2014
On the basis of morphological differences, three subspecies of Black-tailed Godwit (Limosa limosa) have been recognized (L. l. limosa, L. l. islandica and L. l. melanuroides). In previous studies... Show moreOn the basis of morphological differences, three subspecies of Black-tailed Godwit (Limosa limosa) have been recognized (L. l. limosa, L. l. islandica and L. l. melanuroides). In previous studies mitochondrial DNA (mtDNA) sequence data showed minimal genetic divergence between the three subspecies and an absence of sub-structuring within L. l. limosa. Here, population genetic structure and phylogeographic patterns have been analyzed using COI, HVR1 and HVR2 mtDNA sequence data as well as 12 microsatellite loci (nuDNA). The nuDNA data suggest genetic differentiation between L. l. limosa from Sweden and The Netherlands, between L. l. limosa and L. l. islandica, but not between L. l. limosa and L. l. melanuroides. However, the mtDNA data were not consistent with the nuDNA pattern. mtDNA did support a split between L. l. melanuroides and L. l. limosa/L. l. islandica and also demonstrated two L. l. limosa haplotype clusters that were not geographically isolated. This genetic structure can be explained by a scenario of isolation of L. l. melanuroides from L. l. limosa in Beringia during the Last Glacial Maximum. During the Pleistocene separation of L. l. islandica from L. l. limosa occurred, followed by colonization of Iceland by the L. l. islandica during the Holocene. Within L. l. limosa founder events, followed by population expansion, took place during the Holocene also. According to the patterns observed in both markers together and their geographic separation, we propose that the three traditional subspecies indeed represent three separate genetic units. Show less
Population growth and the drop in the returns from the major cash crop (coffee) for small farmers are the main drivers that have influenced the farming systems and mobility of farmers in the... Show morePopulation growth and the drop in the returns from the major cash crop (coffee) for small farmers are the main drivers that have influenced the farming systems and mobility of farmers in the Western Highlands of Cameroon (WHC). The main objective of this research activity was to determine the interactions between farming systems and human mobility in the WHC. A comparative study was conducted through household and field surveys in three villages and conceptualized based on the systems approach. The different types of mobility were influenced by household social factors, the quest for ‘high valued' farm plots and hired labour. Urban-rural migration contributed to occupation diversification and social mobility. The sustainability factor was a function of land use intensity, intensity of off-farm inputs, the household adjustment factor and mobility of the household. The sacred groves were rich in plant diversity of varied ecological and economic importance. Nitrogen mining was common at all levels of the farming system. These determinants and types of mobility claims are pertinent to the research area; the sustainability results of the farming systems reflect the reality on the ground; the nutrient flux evaluated at the crop and farm levels constitute a valuable database for future research. Show less
Most scientific literature on hyena-human interrelationships in Africa sug-gests conflict situations, often resulting in the killing of hyenas. Hyenas survive with difficulty in human-altered... Show moreMost scientific literature on hyena-human interrelationships in Africa sug-gests conflict situations, often resulting in the killing of hyenas. Hyenas survive with difficulty in human-altered habitats and coexistence between hyenas and local communities is problematic. This is because hyenas need extensive areas, usually with few people and sufficient prey. In contrast to this, the present dissertation presents an exceptional case of peaceful co-existence between hyenas and humans. Based on regular observations of hyenas and anecdotal reports, I hypothesized that hyenas in the Tigray re-gion, northern Ethiopia, survive in human-dominated landscapes because of a unique combination of adaptation to anthropogenic food and cultural tolerance towards hyenas. My research aimed to investigate hyena ecology and behavior in human-dominated and prey-depleted landscapes in Tigray. Hyenas are common in many parts of Ethiopia, and in most of those areas, prey populations have been depleted. In northern Ethiopia, the natural prey base is depleted due to agricultural expansion, deforestation, human settle-ment, and habitat fragmentation and degradation Show less
To seek answers to the issues on GM corn adoption in the Philippines, the thesis focused to find answers on the general question: How can genetically modified (GM) corn and its attributed changes... Show moreTo seek answers to the issues on GM corn adoption in the Philippines, the thesis focused to find answers on the general question: How can genetically modified (GM) corn and its attributed changes in agricultural practices affect the agro-ecosystem's biodiversity and the economic status and social life of the farmers? Survey of Asian corn borer (ACB) in Chapter2 showed that Bt corn efficiently reduce borer pest problem and damage to plants by 44%. No secondary pest outbreak was found in Bt cornfields yet, occurrence of ACB though at an insignificant level, could imply potential development of Bt toxin resistance. On biodiversity (Chapters3 and 4), the total invertebrate abundance, surface dwellers and soil dwellers were significantly higher in non-GM cornfields than in Bt and BtHT cornfields. Insecticide-sprayed non-GM cornfields harbored more invertebrates than unsprayed Bt or BtHT cornfield. Surveyed cornfields with a minimum of two years cultivation of GM corn manifested that non-Bt cornfields had significantly higher abundance and species richness of non-target invertebrates than the Bt and BtHT fields. On economic aspect (Chapter5), the non-GM corn was not statistically different from Bt, BtHT and HT corn in terms of production output(PO), net income(NI), production-cost ratio(M) and return on investments(ROI). Results of econometric and Blinder-Oaxaca analyses demonstrate that at present GM corn hybrids do not explicitly manifest economic advantage compared to non-GM corn. On social aspect (Chapter6), GM corn adoption proved to be influenced by the perceived economic advantage, extent of knowledge, level of satisfaction and extent of first-hand experience. The foremost reason for not adopting GM corn was the cost of seed. Herbicide-tolerant (HT) corn, Bacillus thuringiensis (Bt) corn, BtHT corn, abundance, species richness, Asian corn borer, secondary pest, genetically modified (GM) corn, non-GM corn, farm economics, decomposition analysis Show less
