Category Archives: Peer Reviewed Article Review

downscaling

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Here is a useful (to me, at least) Hydrology and Earth System Sciences open article on spatial and temporal downscaling of climate change model output.

Information on extreme precipitation for future climate is needed to assess the changes in the frequency and intensity of flooding. The primary source of information in climate change impact studies is climate model projections. However, due to the coarse resolution and biases of these models, they cannot be directly used in hydrological models. Hence, statistical downscaling is necessary to address climate change impacts at the catchment scale.

This study compares eight statistical downscaling methods (SDMs) often used in climate change impact studies. Four methods are based on change factors (CFs), three are bias correction (BC) methods, and one is a perfect prognosis method. The eight methods are used to downscale precipitation output from 15 regional climate models (RCMs) from the ENSEMBLES project for 11 catchments in Europe. The overall results point to an increase in extreme precipitation in most catchments in both winter and summer. For individual catchments, the downscaled time series tend to agree on the direction of the change but differ in the magnitude. Differences between the SDMs vary between the catchments and depend on the season analysed. Similarly, general conclusions cannot be drawn regarding the differences between CFs and BC methods. The performance of the BC methods during the control period also depends on the catchment, but in most cases they represent an improvement compared to RCM outputs. Analysis of the variance in the ensemble of RCMs and SDMs indicates that at least 30% and up to approximately half of the total variance is derived from the SDMs. This study illustrates the large variability in the expected changes in extreme precipitation and highlights the need for considering an ensemble of both SDMs and climate models. Recommendations are provided for the selection of the most suitable SDMs to include in the analysis.

What is potentially useful to me is that they went to a one day time scale, and they defined an “extreme precipitation index” for storms expected to happen once a year or less on average. I am interested in how or whether these concepts can be applied to “typical” hydrologic conditions that happen at the more-than-once-a-year level. Drought and flooding are probably the two most concerning conditions impacted by climate change, but there are also questions being asked about water quality, and it is the “typical” conditions that most come into play.

ecological footprint vs. planetary boundary

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This article in Ecological Economics tries to link the concepts of planetary boundaries and ecological footprint.

While in recent years both environmental footprints and planetary boundaries have gained tremendous popularity throughout the ecological and environmental sciences, their relationship remains largely unexplored. By investigating the roots and developments of environmental footprints and planetary boundaries, this paper challenges the isolation of the two research fields and provides novel insights into the complementary use of them. Our analysis demonstrates that knowledge of planetary boundaries improves the policy relevance of environmental footprints by providing a set of consensus-based estimates of the regenerative and absorptive capacity at the global scale and, in reverse, that the planetary boundaries framework benefits from well-grounded footprint models which allow for more accurate and reliable estimates of human pressure on the planet’s environment. A framework for integration of environmental footprints and planetary boundaries is thus proposed. The so-called footprint–boundary environmental sustainability assessment framework lays the foundation for evolving environmental impact assessment to environmental sustainability assessment aimed at measuring the sustainability gap between current magnitudes of human activities and associated capacity thresholds. As a first attempt to take advantage of environmental footprints and planetary boundaries in a complementary way, there remain many gaps in our knowledge. We have therefore formulated a research agenda for further scientific discussions, mainly including the development of measurable boundaries in relation to footprints at multiple scales and their trade-offs, and the harmonization of the footprint and boundary metrics in terms of environmental coverage and methodological choices. All these points raised, in our view, will play an important role in setting practical and tangible policy targets for adaptation and mitigation of worldwide environmental unsustainability.

I like ecological footprint because there is no ambiguity between stocks and flows. Natural capital is the underlying stock. The ecological footprint is a proxy for natural capital, the equivalent land area required to produce the annual flow of ecosystem services. It is very intuitive that if the ecological footprint is greater than the size of the Earth, you are digging yourself a  deeper hole each year, and if it is less, you are digging yourself out of the hole. Natural capital is like a huge trust fund or endowment that we can live off of for a long time. But if we are consuming more than the interest produced each year, there will eventually come a day when the trust fund is depleted.

Planetary boundaries, on the other hand, try to measure a mish-mash of stocks and flows. Fertile farmland, for example, is clearly a stock of natural capital. But the amount of fresh water consumed each year is an annual flow of ecosystem services. Atmospheric carbon dioxide concentration is a stock – a sort of anti-ecosystem service, because it represents the opposite of the atmosphere’s ability to absorb further emissions (which are an annual flow). So it all sounds very scholarly, but it needs some cleanup before it will be a clear framework for figuring out what course of action we should be taking.

urban agriculture and carbon emissions

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Here’s an article from Landscape and Urban Planning making a connection between urban agriculture and greenhouse gas emission reductions. It makes sense – any food that comes from nearby will reduce transportation energy use, air pollution, and carbon emissions. We could either decide to do this for ethical reasons, or we could build more of those external costs in the price. It probably makes sense to do some of each.

The expansion of urban agriculture assists in reducing greenhouse gas (GHG) emissions not only by producing food but also by reducing the amount of food transported from farming areas and therefore reducing the food mileage. This study seeks to estimate “the expected GHG reduction effect” in the case of a revitalization of urban agriculture. For this purpose, this study first calculated the area available for urban farming by targeting the metropolitan area of Seoul and then calculated the production per unit area by focusing on “the crops suitable for urban agriculture”. Using this estimated value, the study estimated crop production, the resultant food mileage decrement, and the reduction of carbon dioxide (CO2) emissions that could be obtained if the Seoul metropolis introduced urban agriculture. The results estimated that if the Seoul metropolis implemented urban agriculture in a 51.15 km2 area, it would be possible to reduce CO2 emissions by 11.67 million kg annually. This numerical value is the same amount of CO2 absorbed annually by 20.0 km2 of pine forests and 10.2 km2 of oak tree forests that are 20 years old. From the perspective of GHG reduction effects in the transportation sector, urban agriculture is expected to produce a considerable effect in diverse aspects such as the habituation of green growth, self-sufficiency, and food security.

saving energy by saving water

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An article in Journal of Water Resources Planning and Management quantifies the energy savings that result from water conservation.

Saving water saves energy. Consequently, implementing integrated water management (IWM) measures that reduce potable water consumption, stormwater runoff, and wastewater generation can potentially translate into significant energy savings. In this paper, the energy savings associated with IWM measures of rainwater harvesting and gray-water reuse are estimated, both at national and local utility scales using published data. At the national scale, it is estimated in this paper that up to 3.8  billion kWh and $270 million can potentially be saved annually by replacing landscape irrigation and other outdoor water uses through rainwater harvesting alone, and up to 14  billion kWh and $950 million in combination with gray-water reuse. Similarly, in Charlotte, North Carolina, the local water utility can potentially save up to 31  million kWh and $1.8 million annually. However, annual energy and associated cost savings per household are low at either scale, ranging between 1 and 120 kWh with associated cost savings of less than $10. These results are discussed in terms of energy savings’ role in IWM policy considerations and promotion of sustainable water use in urban areas.

groundwater

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This paper in Water Resources Research is about global groundwater depletion and pollution, and how groundwater can be managed better.

With rivers in critical regions already exploited to capacity throughout the world and groundwater overdraft as well as large-scale contamination occurring in many areas, we have entered an era in which multiple simultaneous stresses will drive water management. Increasingly, groundwater resources are taking a more prominent role in providing freshwater supplies. We discuss the competing fresh groundwater needs for human consumption, food production, energy, and the environment, as well as physical hazards, and conflicts due to transboundary overexploitation. During the past 50 years, groundwater management modeling has focused on combining simulation with optimization methods to inspect important problems ranging from contaminant remediation to agricultural irrigation management. The compound challenges now faced by water planners require a new generation of aquifer management models that address the broad impacts of global change on aquifer storage and depletion trajectory management, land subsidence, groundwater-dependent ecosystems, seawater intrusion, anthropogenic and geogenic contamination, supply vulnerability, and long-term sustainability. The scope of research efforts is only beginning to address complex interactions using multi-agent system models that are not readily formulated as optimization problems and that consider a suite of human behavioral responses.

They get something important right here, which is that if you are formulating a question in a way that the answer can be “optimized”, you have probably defined the question much too narrowly. Water resources are one part of much larger complex natural and social systems. Modeling and technical analysis is important to pare the universe of all possible decisions down to a smaller set where each possible decision is close to “optimal” or efficient in the technical and economic senses. But then this information needs to be fed into a stakeholder or political process where a much wider range of factors can be considered and decisions made.

I am concerned that the current laser focus on “science, technology, engineering, and math” in education is pushing people too far down the path of expecting clear-cut technocratic answers to questions that have messy political and cultural dimensions in reality. All these subjects are good to study, but they need to pared with solid education in planning processes and tools, and an appreciation of systems in general.

photosynthesis

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From the journal Cell, here is a long, technical but interesting open source article on photosynthesis. First, it concludes that the current rate of increase in grain yields will not be sufficient to keep up with population and demand growth through 2050. Then they go through a range of biotechnology research avenues that hold promise to boost photosynthetic efficiency by up to 60%. They argue that the pipeline from beginning the research to seeing it pay off could be 20-30 years. With a lag this long, we can’t just wait until scarcity develops and drives up food prices enough to make the investments obviously profitable. Instead, the research needs to start now.

Two questions come to mind. First, is it the right approach to rely on biotechnology to increase yields so that demand can keep growing forever? Or should we be finding smarter ways to reduce waste, modify lifestyles and make do with what we are producing now? If we remove sunlight as a limiting factor, something else may become the limiting factor, such as water or phosphorus.

Second, if we create super-efficient crops is there a chance they will escape into native ecosystems and choke out all our native plants? Maybe the kinds of modifications that help annual crops produce more edible biomass under industrial field conditions won’t help them compete in the wild at all – you don’t hear about genetically modified corn or wheat straying far afield now. But it still seems like the ethics need to be considered.

 

antibiotics on the farm

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Here’s a journal article about antibiotic use on farms worldwide. Pigs get the highest doses relative to their body size, followed closely by chickens, then cows as a distant third. Developing countries are expected to increase their use by a lot as their populations grow and demand more meat.

Demand for animal protein for human consumption is rising globally at an unprecedented rate. Modern animal production practices are associated with regular use of antimicrobials, potentially increasing selection pressure on bacteria to become resistant. Despite the significant potential consequences for antimicrobial resistance, there has been no quantitative measurement of global antimicrobial consumption by livestock. We address this gap by using Bayesian statistical models combining maps of livestock densities, economic projections of demand for meat products, and current estimates of antimicrobial consumption in high-income countries to map antimicrobial use in food animals for 2010 and 2030. We estimate that the global average annual consumption of antimicrobials per kilogram of animal produced was 45 mg⋅kg−1, 148 mg⋅kg−1, and 172 mg⋅kg−1 for cattle, chicken, and pigs, respectively. Starting from this baseline, we estimate that between 2010 and 2030, the global consumption of antimicrobials will increase by 67%, from 63,151 ± 1,560 tons to 105,596 ± 3,605 tons. Up to a third of the increase in consumption in livestock between 2010 and 2030 is imputable to shifting production practices in middle-income countries where extensive farming systems will be replaced by large-scale intensive farming operations that routinely use antimicrobials in subtherapeutic doses. For Brazil, Russia, India, China, and South Africa, the increase in antimicrobial consumption will be 99%, up to seven times the projected population growth in this group of countries. Better understanding of the consequences of the uninhibited growth in veterinary antimicrobial consumption is needed to assess its potential effects on animal and human health.

environmental regulations and profitability

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If I understand this somewhat convoluted abstract from Ecological Economics correctly, empirical evidence shows that environmental regulation can actually increase corporate profitability by incentivizing innovation. The data also show that investors believe the exact opposite.

The Porter hypothesis asserts that properly designed environmental regulation motivates firms to innovate, which ultimately improves profitability. In this study, we test empirically the Porter hypothesis and the competing hypothesis that regulation undermines profitability (“costly regulation hypothesis”). In particular, we estimate the effect of clean water regulation, as reflected in the stringency of firm-specific effluent limits for two regulated pollutants, on the profitability of chemical manufacturing firms. As our primary contribution, we contrast the effect of clean water regulation on actual profitability outcomes and its effects on investors’ expectations of profitability. Our results for actual profitability are consistent with the Porter hypothesis, while our results for expected profitability are consistent with the costly regulation hypothesis. Thus, our empirical results demonstrate that investors do not appear to value the positive effect of tighter clean water regulation on actual profitability.

designing fragmented ecosystems

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This article in Trends in Ecology and Evolution is about purposely controlling spatial fragmentation in ecosystems in order to maximize ecosystem services. If I understand correctly, their hypothesis seems to be that a system that is fragmented in a carefully designed way could provide more ecosystem services than an unfragmented system.

Landscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation’s expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation’s effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services.

This idea is important to the idea that we could hypothetically design a civilization that is not only less bad than the one we have now, but one that is actually good for the planet and people.

critical natural capital

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This article in Ecological Economics is about the idea of critical natural capital. Critical natural capital is meant to bridge the gap between strong sustainability, which says manufactured capital cannot be substituted for natural capital, and weak sustainability, which says it can. Critical natural capital says that some, but not all, of it can be substituted, because some of it is, well, critical.

The other theme of this paper is the “capability approach”, which is based on the ideas of Amartya Sen. Reading Amartya Sen is on my list of things to do eventually someday, but I haven’t gotten to that yet.

This article is an attempt to conceptually improve the notion of strong sustainability by creating a rapprochement between its core concept, critical natural capital, and the capability approach. We first demonstrate that the capability approach constitutes a relevant framework for analysing the multiple links between human well-being and critical natural capital. Second, we demonstrate that the rapprochement between critical natural capital and the capability approach can form both the normative basis and the informational basis for a deliberative approach to human development which embraces a strong sustainability perspective. This conceptual rapprochement, as illustrated in our case study, opens up avenues of research towards the practical implementation of human development projects from a strong sustainability perspective.