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AbstractWhile several recent studies have focused on global insect population trends, all are limited in either space or taxonomic scope. As global monitoring programs for insects are currently not implemented, inherent biases exist within most data. Expert opinion, which is often widely available, proves to be a valuable tool where hard data are limited. Our aim is to use global expert opinion to provide insights on the root causes of potential insect declines worldwide, as well as on effective conservation strategies that could mitigate insect biodiversity loss. We obtained 753 responses from 413 respondents with a wide variety of spatial and taxonomic expertise. The most relevant threats identified through the survey were agriculture and climate change, followed by pollution, while land management and land protection were recognized as the most significant conservation measures. Nevertheless, there were differences across regions and insect groups, reflecting the variability within the most diverse class of eukaryotic organisms on our planet. Lack of answers for certain biogeographic regions or taxa also reflects the need for research in less investigated settings. Our results provide a novel step toward understanding global threats and conservation measures for insects.

Abstract The objective of this study was to investigate the effects of particle size reduction and solubilization on biogas production from food waste (FW). To clarify the effects of volatile fatty acids (VFAs) in the digestion process, the relationship between particle size and VFA accumulation was investigated in detail. For this purpose, substrates of various particle sizes were prepared by bead milling to support hydrolysis. Batch anaerobic digestion experiments were carried out using these pretreated substrates at mesophilic temperature for a period of 16 days. The results of pretreatment showed that the mean particle size (MPS) of substrates ground with a bead mill decreased from 0.843 to 0.391 mm, and solubilization accounted for approximately 40% of the total chemical oxygen demand (total COD) for grinding pretreatment by bead milling. Anaerobic digestion batch experiments revealed that MPS reduced by bead milling at 1000 rpm improved methane yield by 28% compared with disposer treatment. Moreover, this may have increased microbial degradation during the VFA production process with increasing total number of revolutions (operation time × revolutions per minute). However, excessive reduction of the particle size of the substrate resulted in VFA accumulation, decreased methane production, and decreased solubilization in the anaerobic digestion process. These results suggest that optimized reduction of the particle size of the substrate in conjunction with optimized microbial growth could improve the methane yield in anaerobic digestion processes.

The goal of this study is to determine the difference in CO2 emissions between 2019-2020 and 2020-2021, more specifically during lockdown periods during the COVID-19 pandemic. In the beginning of the pandemic, most countries were forced into lockdowns, and a countless number of people had to continue their daily work from home in isolation. Previously, people would go to an office or to school and leave their houses empty for eight hours, without having lights or any electronics on. Because of this, there should be a direct correlation between electricity usage before and during lockdowns, as a private residence should have higher electricity consumption during 2020-2021, when they are at home. Using machine learning, we will investigate to see if COVID-19 affected CO2 emissions as a result of more electricity usage in private residences. A model will be made to predict what the CO2 emissions would be for 2019-2020, based on electricity usage data from 2020-2021. Then, the real CO2 emissions from 2019-2020 will be compared with the model’s predicted values, and the difference will indicate if COVID-19 caused an inconsistency between actual and predicted CO2 emissions. Factors that were taken into account when making a model were independent variables relating to outdoor conditions, the number of people living in the house, and the temperature that the thermostat is set at, making the response variable CO2 emissions.

In this paper we investigate the prospects for the large-scale use of low-emission energy technologies in Africa. Many African countries have recently experienced substantial economic growth and aim at fulfilling much of the energy needs associated with continuing along paths of economic expansion by exploiting their large domestic potentials of renewable forms of energy. Important benefits of the abundant renewable energy resources in Africa are that they allow for stimulating economic development, increasing energy access and alleviating poverty, while simultaneously avoiding emissions of greenhouse gases. In this study we analyse what the likely energy demand in Africa could be until 2050, and inspect multiple scenarios for the concomitant levels of greenhouse gas emissions and emission intensities. We use the TIAM-ECN model for our study, which enawbbles detailed energy systems research through a technology-rich cost-minimisation procedure. The results from our analysis fully support an Africa-led effort to substantially enhance the use of the continent's renewable energy potential. But they suggest that the current aim of achieving 300 GW of additional renewable electricity generation capacity by 2030 is perhaps unrealistic, even given high GDP and population growth: we find figures that are close to half this level. On the other hand, we find evidence for leap-frogging opportunities, by which renewable energy options rather than fossil fuels could constitute the cost-optimal solution to fulfil most of Africa's growing energy requirements. An important benefit of leap-frogging is that it avoids an ultimately expensive fossil fuels lock-in that would fix the carbon footprint of the continent until at least the middle of the century.

The potential for global forest cover The restoration of forested land at a global scale could help capture atmospheric carbon and mitigate climate change. Bastin et al. used direct measurements of forest cover to generate a model of forest restoration potential across the globe (see the Perspective by Chazdon and Brancalion). Their spatially explicit maps show how much additional tree cover could exist outside of existing forests and agricultural and urban land. Ecosystems could support an additional 0.9 billion hectares of continuous forest. This would represent a greater than 25% increase in forested area, including more than 200 gigatonnes of additional carbon at maturity.Such a change has the potential to store an equivalent of 25% of the current atmospheric carbon pool. Science , this issue p. 76 ; see also p. 24

AbstractXylella fastidiosais a bacterium that infects crops like grapevines, coffee, almonds, citrus and olives, causing economically devastating damage. There is, however, little understanding of the genes that contribute to resistance, the genomic architecture of resistance, and the potential role of climate in shaping resistance, in part because major crops like grapevines (V. vinifera) are not resistant to the bacterium. Here we studied a wild grapevine species,Vitis arizonica, that segregates for resistance toX. fastidiosa. Using genome-wide association, we identified candidate genes that mediate the host response toX. fastidiosainfection. We uncovered evidence that resistance requires genes from multiple genomic regions, based on data from breeding populations and from additionalVitisspecies. We also inferred that resistance evolved more than once in the wild, suggesting that wildVitisspecies may be a rich source for resistance alleles and mechanisms. Finally, resistance inV. arizonicawas climate dependent, because individuals from low (< 10°C) temperature locations in the wettest quarter were typically susceptible to infection, likely reflecting a lack of pathogen pressure in these climates. Surprisingly, climate was nearly as effective a predictor of resistance phenotypes as some genetic markers. This work underscores that pathogen pressure is likely to increase with climate, but it also provides genetic insight and tools for breeding and transforming resistant crops.

The European Green Deal is a political milestone aiming to promote a carbon-neutral economy in the European Union. Decarbonizing the complex food sector requires the unified interaction among effective climate policies, economic instruments, and initiatives involving multiple stakeholders. Despite increasing efforts to highlight the importance of innovations and finance to achieve sustainable food supply chains (FSC), comprehensive information about related opportunities and barriers to mitigating emissions in the food sector is still under-explored. To cover this gap, this paper applies an existing industrial policy framework under the lens of the EU FSC to identify potential strategies that should help achieve the needed financial means and innovation actions, as well as to gauge political alignment across FSC stages. Methodologically, the pillars proposed in the framework are linked to multi-stakeholders’ initiatives engaged in achieving net-zero emissions. The paper highlights three main implications of the identified interlinkages. First, political directionality related to the food sector should be more comprehensively tailored to account for the specificities of all stages of the FSC. Second, research and development projects shall likewise cover all stages, instead of emphasizing only food production and agricultural systems. Finally, multiple stakeholders are crucial as promoters of technology and innovation towards a green economy. Nevertheless, initiatives should be integrated into political discussions in order to promote civil awareness, sustainable food and services demand, aligned to political guidelines.