Water pollution scenarios and response options for China.

China has formulated several policies to alleviate the water pollution load, but few studies have quantitatively analyzed their impacts on future water pollution loads in China. Based on grey water footprint (GWF) assessment and scenario simulation, we analyze the water pollution (including COD, NH3-N, TN and TP) in China from 2021 to 2035 under different scenarios for three areas: consumption-side, production-side and terminal treatment. We find that under the current policy scenario, the GWF of COD, NH3-N, TN, and TP in China could be reduced by 15.0 % to 39.9 %; the most effective measures for GWF reduction are diet structure change (in the consumption-side area), and the wastewater treatment rate and livestock manure utilization improvement (in the terminal treatment area). However, the GWF will still increase in 8 provinces, indicating that the current implemented policy is not universally effective in reducing GWF across all provinces. Under the technical improvement scenario, the GWF of the four pollutants will decrease by 54.9 %-71.1 % via improvements in the current measures related to current policies and new measures in the production-side area and the terminal treatment area; thus, GWF reduction is possible in all 31 provinces. However, some policies face significant challenges in achieving full implementation, and certain policies are only applicable to a subset of provinces. Our detailed analysis of future water pollution scenarios and response options to reduce pollution loads can help to inform the protection of freshwater resources in China and quantitatively assess the effectiveness of policies in other fields.

Allocating capital-associated CO2 emissions along the full lifespan of capital investments helps diffuse emission responsibility.

Capital assets such as machinery and infrastructure contribute substantially to CO2 emissions over their lifetime. Unique features of capital assets such as their long durability complicate the assignment of capital-associated CO2 emissions to final beneficiaries. Whereas conventional approaches allocate emissions required to produce capital assets to the year of formation, we propose an alternative perspective through allocating required emissions from the production of assets over their entire lifespans. We show that allocating CO2 emissions embodied in capital assets over time relieves emission responsibility for the year of formation, with 25‒46% reductions from conventional emission accounts. This temporal allocation, although virtual, is important for assessing the equity of CO2 emissions across generations due to the inertia of capital assets. To re-allocate emission responsibilities to the future, we design three capital investment scenarios with different investment purposes until 2030. Overall, the existing capital in 2017 will still carry approximately 10% responsibilities of China's CO2 emissions in 2030, and could reach more than 40% for capital-intensive service sectors.

Water pollution from pharmaceutical use in livestock farming: Assessing differences between livestock types and production systems.

Livestock production is a major source of pharmaceutical emissions to the environment. The current scientific discourse focuses on measuring and modeling emissions as well as assessing their risks. Although several studies corroborate the severity of pharmaceutical pollution resulting from livestock farming, differences in pollution between livestock types and production systems are largely unknown. In fact, there is no comprehensive analysis of factors influencing pharmaceutical use-the emission's source-in the diverse production systems. To address these knowledge gaps, we developed a framework to investigate pharmaceutical pollution from different livestock production systems and applied it in a first pilot assessment to compare pollution from organic and conventional cattle, pig, and chicken production systems on selected indicator substances, covering antibiotics, antiparasitics, hormones, and nonsteroidal anti-inflammatory drugs (NSAIDs). Given the lack of statistics, for this article we retrieved novel qualitative information about influential factors for pharmaceutical use and pollution from expert interviews and combined this with quantitative data on, among other factors, the environmental behavior of specific substances from the literature. Our analysis reveals that factors across a pharmaceutical's entire life cycle influence pollution. However, not all factors are livestock type or production-system dependent. The pilot assessment furthermore reveals that differences in pollution potential between conventional and organic production exist, but for antibiotics, NSAIDs, and partially for antiparasitics, some factors lead to greater pollution potential in conventional systems, and others in organic systems. For hormones, we identified a comparatively greater pollution potential from conventional systems. Among the indicator substances, the assessment over the entire pharmaceutical life cycle illustrates that flubendazole in broiler production has the greatest per unit impact. The framework and its application in the pilot assessment generated insights useful to identifying which substances, livestock types, production systems, or the combination thereof have great or little pollution potential, informing more sustainable agricultural management practices. Integr Environ Assess Manag 2023;19:1495-1509. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Corrigendum/Erratum to "Livestock water and land productivity in Kenya and their implications for future resource us" [].

[This corrects the article DOI: 10.1016/j.heliyon.2022.e09006.].

The role of context in identifying linkages between SDG 2 (food) and SDG 6 (water).

The Sustainable Development Goals (SDGs) of the United Nation's Agenda 2030 are formulated to promote the development of integrated, multisectoral policies that explicitly consider linkages across SDGs. Although multiple recent studies have tried to identify linkages across SDGs, the role of contextual factors in identifying SDG linkages is neither well described nor understood. For the case of SDG 2 and SDG 6, this study aims to (i) identify linkages-at country and SDG target level-through the application of various quantitative and qualitative identification methods, and (ii) explore contextual factors to explain the differences across identified linkages. Hereto, we first conducted a text analysis of 195 Voluntary National Reviews (VNRs) reported by 159 countries from 2016 to 2020. Next, we synthesized linkages reported by previous qualitative studies and conducted a quantitative (correlation) analysis on the UN's SDG database. Last, we compared identified linkages across methods, paying special attention to the role of context. From the text analysis, we identified 221 country-specific linkages between 25 SDG target pairs and observed that countries increasingly report SDG linkages in their VNRs over time. Comparing text analysis, existing qualitative studies, and our quantitative correlation analysis, we found substantial differences between the number and nature of linkages identified. These differences can be explained in part by methodological considerations, but to a significant extent also by contextual factors, such as project design, technology application, phase of interventions, and project scale. We conclude by discussing the strengths and limitations of the methods involved, and suggestions for future studies. Supplementary Information: The online version contains supplementary material available at 10.1007/s11625-022-01158-3.

Livestock water and land productivity in Kenya and their implications for future resource use.

Population growth and rising affluence increase the demand for agricultural commodities. Associated growth in production increases dependency on natural resources in countries that attempt to meet part or all of the new demand locally. This study assesses the impact of changing meat and milk production on natural resource use in Kenya under three plausible scenarios of socio-economic development, namely Business-As-Usual (BAU), Sustainable Development (SDP) and Kenya Vision 2030 (V2030) scenarios. The IMPACT model is used to estimate projected cattle, sheep, goats and camel production parameters for meat and milk. The BAU and SDP represent standard scenarios for Kenya of a global economic model, IMPACT, while V2030 incorporates in the model features specific to Kenya's medium-term national development plan. We use calculations of water footprint and land footprint as resource use indicators to quantify the anticipated appropriation of water and land resources for meat and milk production and trade by 2040. Though camel dairy production numbers increase the most by quadrupling between 2005 and 2040, it is cattle dairy production that significantly determined gains in production between the scenarios. Productivity gains under the SDP scenario does not match the investments made thereby leading to only slightly better values for water and land productivity than those achieved under the BAU scenario. Relative to the BAU scenario, improvement in land productivity under the V2030 scenario is the most dramatic for shoat milk production in the arid and semi-arid systems but the least marked for cattle milk production in the humid system. By quantifying water and land productivity across heterogenous production systems, our findings can aid decision-makers in Kenya and other developing countries to understand the implications of strategies aimed at increasing domestic agricultural and livestock production on water and land resources both locally and through trade with other countries.

An integrated modelling approach to derive the grey water footprint of veterinary antibiotics.

Water pollution by veterinary antibiotics (VAs) resulting from livestock production is associated with severe environmental and human health risks. While upward trends in global animal product consumption signal that these risks might exacerbate toward the future, VA related water pollution is currently insufficiently understood. To increase this understanding, the present research assesses processes influencing VA pollution from VA administration to their discharge into freshwater bodies, using an integrated modelling approach (IMA). For the VAs amoxicillin, doxycycline, oxytetracycline, sulfamethazine, and tetracycline we estimate loads administered to livestock, excretion, degradation during manure storage, fate in soil and transport to surface water. Fate and transport are modelled using the VA transport model (VANTOM), which is fed with estimates from the Pan-European Soil Erosion Risk Assessment (PESERA). The grey water footprint (GWF) is used to indicate the severity of water pollution in volumetric terms by combining VA loads and predicted no effect concentrations. We apply our approach to the German-Dutch Vecht river catchment, which is characterized by high livestock densities. Results show a VA mass load decrease larger than 99% for all substances under investigation, from their administration to surface water emission. Due to metabolization in the body, degradation during manure storage and degradation in soil, VA loads are reduced by 45%, 80% and 90% on average, respectively. While amoxicillin and sulfamethazine dissipate quickly after field application, significant fractions of doxycycline, oxytetracycline and tetracycline accumulate in the soil. The overall Vecht catchment's GWF is estimated at 250,000 m3 yr-1, resulting from doxycycline (81% and 19% contribution from the German and Dutch catchment part respectively). Uncertainty ranges of several orders of magnitude, as well as several remaining limitations to the presented IMA, underscore the importance to further develop and refine the approach.

Linking the Environmental Pressures of China's Capital Development to Global Final Consumption of the Past Decades and into the Future.

China's rapid growth was fueled by investments that grew more than 10-fold since 1995. Little is known about how the capital assets acquired, while being used in productive processes for years or decades, satisfy global final consumption of goods and services, or how the resource use and emissions that occurred during capital formation are attributable to past or future consumption. Here, enabled by a new global model of capital formation and use, we quantify the linkages over the past 2 decades and into the future between six environmental pressures (EPs) associated with China's capital formation and attributable to Chinese as well as non-Chinese consumption. We show that only 35% of the capital assets acquired by China from 1995 to 2015, representing 32-39% of the associated EPs (e.g., water consumption, greenhouse gas (GHG) emissions, and metal ore extractions), have been depreciated, while the majority rest will serve future production and consumption. The outsourcing of capital services and the associated EPs are considerable, ranging from 14 to 25% of depending on the EP indicators. Without accounting for the capital-final consumption linkages across time and space, one would miscalculate China's environmental footprints related to the six EPs by big margins, from -61% to +114%.

Capping Human Water Footprints in the World's River Basins.

Increased water demand and overexploitation of limited freshwater resources lead to water scarcity, economic downturn, and conflicts over water in many places around the world. A sensible policy measure to bridle humanity's water footprint, then, is to set local and time-specific water footprint caps, to ensure that water appropriation for human uses remains within ecological boundaries. This study estimates-for all river basins in the world-monthly blue water flows that can be allocated to human uses, while explicitly earmarking water for nature. Addressing some implications of temporal variability, we quantify trade-offs between potentially violating environmental flow requirements versus underutilizing available flow-a trade-off that is particularly pronounced in basins with a high seasonal and interannual variability. We discuss several limitations and challenges that need to be overcome if setting water footprint caps is to become a practically applicable policy instrument, including the need (for policy makers) to reach agreement on which specific capping procedure to follow. We conclude by relating local and time-specific water footprint caps to the planetary boundary for freshwater use.

Trade-off between blue and grey water footprint of crop production at different nitrogen application rates under various field management practices.

In irrigated crop production, nitrogen (N) is often applied at high rates in order to maximize crop yield. With such high rates, the blue water footprint (WF) per unit of crop is low, but the N-related grey WF per unit of crop yield is relatively high. This study explores the trade-off between blue and grey WF at different N-application rates (from 25 to 300 kg N ha-1 y-1) under various field management practices. We first analyse this trade-off under a reference management package (applying inorganic-N, conventional tillage, full irrigation). Next, we estimate the economically optimal N-application rate when putting a price to pollution. Finally, we consider the blue-grey WF trade-off for other management packages, a combination of inorganic-N or organic-N with conventional tillage or no-tillage, and full or deficit irrigation. We use the APEX model to simulate soil water and N balances and crop growth. As a case study, we consider irrigated maize on loam soil for the period 1998-2012 in a semi-arid environment in Spain. The results for the reference package show that increasing N application from 50 to 200 kg N ha-1, with crop yield growing by a factor 3, involves a trade-off, whereby the blue WF per tonne declines by 60% but the N-related grey WF increases by 210%. Increasing N application from 25 to 50 kg N ha-1, with yield increasing by a factor 2, is a no-regret move, because blue and grey WFs per tonne are reduced by 40% and 8%, respectively. Decreasing N application from 300 to 200 kg N ha-1 is a no-regret move as well. The minimum blue WF per tonne is found at N application of 200 kg N ha-1, with a price of 8 $ kg-1 of N load to water pollution the economically optimal N-application rate is 150 kg N ha-1.

Expected increase in staple crop imports in water-scarce countries in 2050.

Population growth paired with growing freshwater scarcity in various parts of the world will reduce the potential of food self-sufficiency in many countries. Today, two thirds of the global population are already living in areas facing severe water scarcity at least one month of the year. This raises the importance of addressing the relationship between water availability and food import in water-scarce countries. Net import of staple crops (including cereals, roots, and tubers) is analysed in relation to water availability per capita for the period 1961-2010, considering five decadal averages. The relation found is used, together with the population growth scenarios from the United Nations, to project staple crop imports in water-scarce countries for the year 2050. As a result of population growth in water-scarce countries alone, global international trade in staple crops is projected to increase by a factor of 1.4-1.8 towards 2050 (compared to the average in 2001-2010), in order to meet the staple food needs of the 42 most water-scarce countries in the world.

Virtual water trade patterns in relation to environmental and socioeconomic factors: A case study for Tunisia.

Growing water demands put increasing pressure on local water resources, especially in water-short countries. Virtual water trade can play a key role in filling the gap between local demand and supply of water-intensive commodities. This study aims to analyse the dynamics in virtual water trade of Tunisia in relation to environmental and socio-economic factors such as GDP, irrigated land, precipitation, population and water scarcity. The water footprint of crop production is estimated using AquaCrop for six crops over the period 1981-2010. Net virtual water import (NVWI) is quantified at yearly basis. Regression models are used to investigate dynamics in NVWI in relation to the selected factors. The results show that NVWI during the study period for the selected crops is not influenced by blue water scarcity. NVWI correlates in two alternative models to either population and precipitation (model I) or to GDP and irrigated area (model II). The models are better in explaining NVWI of staple crops (wheat, barley, potatoes) than NVWI of cash crops (dates, olives, tomatoes). Using model I, we are able to explain both trends and inter-annual variability for rain-fed crops. Model II performs better for irrigated crops and is able to explain trends significantly; no significant relation is found, however, with variables hypothesized to represent inter-annual variability.

Urban consumption of meat and milk and its green and blue water footprints-Patterns in the 1980s and 2000s for Nairobi, Kenya.

THE PROBLEM: Various studies show that the developing world experiences and will continue to experience a rise in consumption of animal proteins, particularly in cities, as a result of continued urbanization and income growth. Given the relatively large water footprint (WF) of animal products, this trend is likely to increase the pressure on already scarce water resources. AIM: We estimate, analyse and interpret the changes in consumption of meat and milk between the 1980s and 2000s for three income classes in Nairobi, the ratio of domestic production to imports, and the WF (the volume of freshwater consumed) to produce these commodities in Kenya and abroad. RESULTS: Nairobi's middle-income class grew much faster than the overall population. In addition, milk consumption per capita by the middle-income group grew faster than for the city's population as a whole. Contrary to expectation, average meat consumption per capita across all income groups in Nairobi declined by 11%. Nevertheless, total meat consumption increased by a factor 2.2 as a result of population growth, while total milk consumption grew by a factor 5. As a result, the total WF of meat consumption increased by a factor 2.3 and the total WF of milk consumption by a factor 4.2. The increase in milk consumption was met by increased domestic production, whereas the growth in meat consumption was partly met through imports and an enlargement of the footprint in the countries neighbouring Kenya. DISCUSSION AND CONCLUSION: A likely future rise in the consumption of meat and milk in Nairobi will further enlarge the city's WF. Given Kenya's looming blue water scarcity, it is anticipated that this WF will increasingly spill over the borders of the country. Accordingly, policies aimed at meeting the rise in demand for meat and milk should consider the associated environmental constraints and the economic implications both nationally and internationally.