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
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
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
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
In the 90s, organizations in charge of wildlife management in Medellín, released macaws (Psittacidae: Ara) in the city. We report Ara severa, A. chloroptera and A. macao in the city. A group of... Show moreIn the 90s, organizations in charge of wildlife management in Medellín, released macaws (Psittacidae: Ara) in the city. We report Ara severa, A. chloroptera and A. macao in the city. A group of eight individuals, belonging to the latter two species was observed flocking together in the urban area of Medellin. Nest site availability is limited because of urban expansion and logging of old dangerous trees. These macaws are out of their natural range but have shown considerable adaptability. Strategies to manage wildlife in this urban area have been limited. Further work is needed to guarantee the continued survival of these macaws. Show less
