Dynamics of water-energy-food nexus interactions with climate change and policy options

Understanding the dynamics of water-energy-food (WEF) nexus interactions with climate change and human intervention helps inform policymaking. This study demonstrates the WEF nexus behavior under ensembles of climate change, transboundary inflows, and policy options, and evaluates the overall nexus performance using a previously developed system dynamics-based WEF nexus model—WEF-Sask. The climate scenarios include a baseline (1986-2014) and near-future climate projections (2021-2050). The approach is demonstrated through the case study of Saskatchewan, Canada. Results show that rising temperature with increased rainfall likely maintains reliable food and feed production. The climate scenarios characterized by a combination of moderate temperature increase and slightly less rainfall or higher temperature increase with slightly higher rainfall are easier to adapt to by irrigation expansion. However, such expansion uses a large amount of water resulting in reduced hydropower production. In contrast, higher temperature, combined with less rainfall, such as SSP370 (2.4 ℃, -6 mm), is difficult to adapt to by irrigation expansion. Renewable energy expansion, the most effective climate change mitigation option in Saskatchewan, leads to the best nexus performance during 2021-2050, reducing total water demand, groundwater demand, greenhouse gas (GHG) emissions, and potentially increasing water available for food production. In this study, we recommend and use food and power production targets and provide an approach to assessing the impacts of hydroclimate and policy options on the WEF nexus, along with suggestions for adapting the agriculture and energy sectors to climate change.

GIS-based research on climate suitable region of Loquat in Lishui, Zhejiang province of China

To develop a climatic suitability index and conduct the cultivation division of loquat in Lishui, Zhejiang province of China, we introduced the multi-indicator comprehensive risk assessment method to combine with the hazard factor model, necessary climatic elements during the growing season of loquat and geographic information elements. Results show that the annual active accumulated temperature (rainfall ) over most Lishui is more than 4500°C (1600mm). The two climatic factors above can well meet the needs of loquat growth. The frozen injury days over most Lishui during the young fruit period of loquat are more than 10.0 days, which are higher than those during the flowering period. The annual mean number of continuous overcast rain occurrences is less than 4.5. The climatic mean annual occurrence of persistent abnormal high temperature weather is less than 1. Overall, the most suitable area for the cultivation of loquat mainly located over the relatively flat areas such as river valleys and basins, especially the banks of the Oujiang River in Qingtian and Xiaoxi River valley in Jingning. The excellent combinations of light, heat and water with relatively few meteorological disasters just like frozen injury, continuous rain and high temperature provide a good climatic conditions of the high-quality of loquat planting.

Physical processes behind interactions of microplastic particles with natural ice

Microplastic particles (MPs, <5 mm) are found in marine ice in larger quantities than in seawater, however, the distribution pattern within the ice cores is not consistent. To get insights into the most general physical processes behind interactions of ice and plastic particles in cool natural environments, information from academic and applied research is integrated and verified against available field observations. Non-polar molecules of common-market plastics are hydrophobic, so MPs are weak ice nucleators, are repelled from water and ice, and concentrate within air bubbles and brine channels. A large difference in thermal properties of ice and plastics favours concentration of MPs at the ice surface during freeze/thaw cycles. Under low environmental temperatures, falling in polar regions below the glass / brittle-ductile transition temperatures of the common-use plastics, they become brittle. This might partially explain the absence of floating macroplastics in polar waters. Freshwater freezes at the temperature well below that of its maximum density, so the water column is stably stratified, and MPs eventually concentrate at the ice surface and in air bubbles. In contrast, below growing sea ice, mechanisms of suspension freezing under conditions of (thermal plus haline) convection should permanently entangle MPs into ice. During further sea ice growth and aging, MPs are repelled from water and ice into air bubbles, brine channels, and to the upper/lower boundaries of the ice column. Sea ice permeability, especially while melting periods, can re-distribute sub-millimeter MPs through the brine channels, thus potentially introducing the variability of contamination with time. In accord with field observations, analysis reveals several competing factors that influence the distribution of MPs in sea ice. A thorough sampling of the upper ice surface, prevention of brine leakage while sampling and handling, considering the ice structure while segmenting the ice core – these steps may be advantageous for further understanding the pattern of plastic contamination in natural ice.

Awareness and product knowledge of service stakeholders involved in the importation and distribution of HCFC-22 in Botswana

Environmental problems such as global warming, ozone depletion and climate change remain universal subjects of concern, with baneful effects on both the environment and human health. The consumption and venting of ozone depleting substances (ODS) into the atmosphere are the chief anthropogenic cause of ozone depletion. One such manmade ODS with high global warming potential Chlorodifluoromethane (HCFC-22). The MP targeted to phase-out HCFC-22 with obligatory cut-off timelines for its use by 2040 for developing nations. To comply with the HCFC-22 phase-out timelines, meant at embarking on national communications to disseminate information on HCFC-22 phase-out through key stakeholders’ involvement. The achievement of HCFC-22 phase-out strategy depends on participation of key stakeholders in the implementation process. the level of awareness and product knowledge of service stakeholders in the importation and distribution of HCFC-22 in Botswana. customs officers, officers and industrial consumers. Questionnaires and interviews were used to solicit key stakeholders’ views, opinions and perceptions on HCFC-22 phase-out awareness and product knowledge. Results revealed that 87% of the stakeholders are learned and knowledgeable in ODS related service provision. The level of HCFC-22 knowledge and awareness among stakeholders is moderate with distinguished inter-group differences. In particular, industrial consumers had the highest median level of HCFC-22 awareness than other stakeholders, indicating gaps in HCFC-22 phase-out awareness raising and training. About 67% of respondents had low levels of awareness of the HPMP and alternative technologies to HCFC-22. This proposes gaps in information dissemination to key stakeholders and this remains a crucial disparity between the country’s HPMP success lead and lag indicators. There is need to carefully select communication media used in line with the media consumption habits of target markets. Use of popular and commonly accessed social-media platforms would ensure that the HCFC-22 phase-out messages have high chance of reaching targeted stakeholders and the general population.

Effects of eco-environmental damage compensation system with multi-stakeholder engagements: a DSGE perspective from China

We present and estimate a dynamic stochastic general equilibrium model for an eco-environmental damage compensation system (EDCS) with multi-stakeholder engagements. Then we explore the dynamic effect under different shocks such as household and government supervision, environmental damage compensation ratio, pollution emission threshold, and pollution control efforts. The household and government supervision show the positive effect of environmental regulation on conserving energy, abating emission, reducing damage compensation, and increasing economic output. The environmental damage compensation ratio can also contribute to energy conservation and emission reduction, but there are no significant regulation effects of pollutant emission and damage compensation. The pollutant emission threshold and the pollution control efforts have significant environmental regulation effects, but the latter does not significantly restrain high energy consumption. All the shocks mentioned above can effectively improve the green development level.

A scenario analysis under epistemic uncertainty in Natech accidents: imprecise probability reasoning in Bayesian Network

The increasing frequency and severity of Natech accidents warn us to investigate the occurrence mechanism of these events. Cascading disasters chain magnifies the impact of natural hazards due to its propagation through critical infrastructures and socio-economic networks. In order to manipulate imprecise probabilities of cascading events in Natech scenarios, this work proposes an improved Bayesian network （BN） combining with evidence theory to better deal with epistemic uncertainty in Natech accidents than traditional BNs. Effective inference algorithms have been developed to propagate system faulty in a socio-economic system. The conditional probability table (CPT) of BN in the traditional probability approach is modified by utilizing an OR/AND gate to obtain the belief mass propagation in the framework of evidence theory. Our improved Bayesian network methodology makes it possible to assess the impact and damage of Natech accidents under the environment of complex interdependence among accidents with insufficient data. Finally, a case study of Guangdong province, an area prone to natural disasters, is given. The modified Bayesian network is carried out to analyze this area’s Natech scenario. After diagnostic analysis and sensitivity analysis of human factors and the natural factor, we are able to locate the key nodes in the cascading disaster chain. Findings can provide useful theoretical support for urban managers of industrial cities to enhance disaster prevention and mitigation ability.

Unmanned aerial vehicles and deep learning for assessment of anthropogenic marine debris on beaches on an island in a semi-enclosed sea in Japan

The increasing prevalence of marine debris is a global problem, and urgent action for amelioration is needed. Identifying hotspots where marine debris accumulates will enable effective control; however, knowledge on the location of accumulation hotspots remains incomplete. In particular, marine debris accumulation on beaches is a concern. Surveys of beaches require intensive human effort, and survey methods are not standardized. If marine debris monitoring is conducted using a standardized method, data from different regions can be compared. With an unmanned aerial vehicle (UAV) and deep learning computational methods, monitoring a wide area at a low cost in a standardized way may be possible. In this study, we aimed to identify marine debris on beaches through deep learning using high-resolution UAV images by conducting a survey on Narugashima Island in the Seto Inland Sea of Japan. The flight altitude relative to the ground was set to 5 m, and images of a 0.81-ha area were obtained. Flight was conducted twice: before and after the beach cleaning. The combination of UAVs equipped with a zoom lens and operation at a low altitude allows for the acquisition of high resolution images of 1.1 mm/pixel. The training dataset (2970 images) was annotated by using VoTT, categorizing them into two classes: “anthropogenic marine debris” and “natural objects.” Using RetinaNet, marine debris was identified with an average sensitivity of 51% and a precision of 76%. In addition, the abundance and area of marine debris coverage were estimated. In this study, it was revealed that the combination of UAVs and deep learning enables the effective identification of marine debris. The effects of cleanup activities by citizens were able to be quantified. This method can widely be used to evaluate the effectiveness of citizen efforts toward beach cleaning and low-cost long-term monitoring.

Assessment of land use change in the Thuma forest reserve region of Malawi, Africa

A study was conducted in Thuma area in central Malawi to quantify contemporary land cover and to explore the degree of land use change in the Thuma forest reserve area of Malawi by analysing and comparing satellite-derived land cover maps from 1997, 2007 and 2017. The study was carried out using Remote Sensing and Geographic Information System (GIS), focusing on analysis of Landsat 5 ETM and Landsat 8 ORI/TIRS satellite images. The classification was conducted for the following distinct classes; closed forest, open forest, shrubland, savanna grassland, agriculture fields, and water. The analysis revealed that closed forest diminished from 19% in 1997 to 10% in 2007 to 6% in 2017. Open forest reduced from 30% to 21% from 1997 to 2007 but increased to 22% in 2017. Agriculture area almost doubled from 37 % in 1997 to 64 % in 2017. Actual area from 1997 to 2017, shows that closed forest has reduced from 7,000 ha to 3,000 ha while open forest from 12,900 ha to 7800 ha. Savanna grassland has doubled from 5,900 ha to 13,000 ha. However, future studies should use modern satellites such as Sentinel and Landsat 9 for improved quantification of changes. The findings show that even the protected forest reserve (previously dominated by closed forest) is not fully protected from deforestation by local communities. Government and other stakeholders should devise measures to meet the needs of the surrounding communities and the ecological/biophysical needs of the reserves. Based on this study, issues of re-demarcation of the forest reserve and accessed area should also be explored. This study serves as a reference for the management of Thuma Forest Reserve as a refuge for natural tree species, rivers that harbour endemic fish species (Opsaridium microlepis and Opsaridium microcephalis) and the sustainable management of endangered elephants in the reserve.

The rationality of PM2.5 monitoring sites’ locations based on exposure level across eastern China

Due to the heterogeneity of PM2.5 and population distribution, the representativeness of existing monitoring sites is questionable when the monitored data were used to assess the population exposure. By comparing the PM2.5 concentration from a satellite-based dataset named the China High Air Pollutants (CHAP), population and exposure level in urban areas with monitoring stations (UWS) and without monitoring stations (UNS), we discussed the rationality of the current spatial coverage of monitoring stations in eastern China. Through an analysis of air pollution in all urban areas of 256 prefectural-level municipalities in eastern China, we found that the average PM2.5 concentration in UNS in 2015 and 2018 were 52.26 μg/m3 and 41.32 μg/m3, respectively, which were slightly lower than that in UWS (52.98 μg/m3 and 41.48 μg/m3). About 12.1% of the prefectural-level municipalities had higher exposure levels in certain UNS than those in UWS. With the faster growth of UNS population, the gap between exposure levels of UNS and UWS were narrowing. Hence, currently prevalent administration-based principle of site location selection might have higher risk of missing the non-capital urban areas with relatively higher PM2.5 exposure level in the future.

Building adaptive capacity of smallholder agriculture to climate change: evidence synthesis on learning outcomes

Increasing climate uncertainty coupled with more frequent extreme events poses a serious threat to the sustainability of smallholder communities dependent on agriculture for their livelihoods. Whilst there is extensive literature on adaptation options, there is a pressing need to understand what interventions have been successful in building smallholder’s adaptive capacity, and how these have been transferred (nationally and internationally) through learning outcomes. The aim of this rapid evidence assessment was to assess the extent to which learning outcomes have supported initiatives to mainstream adaptation, focussing on three key areas, (i) scaling up climate sensitive adaptive interventions, (ii) the role of knowledge management to promote effective adaptive solutions, and (iii) human-ecosystem interactions in climate change adaptation. A protocol for the review was defined, from which 806 sources of evidence were retrieved. After screening for relevance using inclusion criteria, 91 were selected and the salient evidence extracted and synthesised. Access to knowledge remains one of the most important determinants of smallholders’ decisions to respond to climate risk and a critical element in building adaptive capacity. The way knowledge is generated and exchanged is also directly relevant to securing effective scaling-up pathways. Learning platforms through participatory action research, farmer field schools and community-based initiatives were found to be particularly effective. However, knowledge based on local practices alone may be insufficient to prompt transformative action. Bridging local and external knowledge is critical because it widens the smallholders’ knowledge base and encourages ‘proactive’ adaptation alongside more typical ‘reactive’ strategies. The contribution of evidence reviews to provide new insights to inform decision-making and investment in international development and the implications for advocating climate-sensitive policies at national and global levels are discussed.