Abstract In contrast to most integrated assessment models, with limited transparency on damage functions and recursive temporal dynamics, we use a unique large-dimensional computational global ...climate and trade model, GTAP-DynW, to directly project the possible intertemporal impacts of water and heat stress on global food supply and food security to 2050. The GTAP-DynW model uses GTAP production and trade data for 141 countries and regions, with varying water and heat stress baselines, and results are aggregated into 30 countries/regions and 30 commodity sectors. Blue water stress projections are drawn from WRI source material and a GTAP-Water database to incorporate dynamic changes in water resources and their availability in agricultural production and international trade, thus providing a more general measure for severe food insecurity from water and heat stress damages with global warming. Findings are presented for three representative concentration pathways: RCP4.5-SSP2, RCP8.5-SPP2, and RCP8.5-SSP3 (population growth only for SSPs) and project: (a) substantial declines, as measured by GCal, in global food production of some 6%, 10%, and 14% to 2050 and (b) the number of additional people with severe food insecurity by 2050, correspondingly, increases by 556 million, 935 million, and 1.36 billion compared to the 2020 model baseline.
We compare the health and economic costs of early and delayed mandated suppression and the unmitigated spread of 'first-wave' COVID-19 infections in Australia in 2020. Using a fit-for-purpose ...SIQRM-compartment model for susceptible, infected, quarantined, recovered and mortalities on active cases, that we fitted from recorded data, a value of a statistical life year (VSLY) and an age-adjusted value of statistical life (A-VSL), we find that the economic costs of unmitigated suppression are multiples more than for early mandated suppression. We also find that using an equivalent VSLY welfare loss from fatalities to estimated GDP losses, drawn from survey data and our own estimates of the impact of suppression measures on the economy, means that for early suppression not to be the preferred strategy requires that Australia would have to incur more than 12,500-30,000 deaths, depending on the fatality rate with unmitigated spread, to the economy costs of early mandated suppression. We also find that early rather than delayed mandated suppression imposes much lower economy and health costs and conclude that in high-income countries, like Australia, a 'go early, go hard' strategy to suppress COVID-19 results in the lowest estimated public health and economy costs.
Household survey data for 10 countries are used to quantify and test the importance of price and nonprice factors on residential water demand and investigate complementarities between household ...water‐saving behaviors and the average volumetric price of water. Results show (1) the average volumetric price of water is an important predictor of differences in residential consumption in models that include household characteristics, water‐saving devices, attitudinal characteristics and environmental concerns as explanatory variables; (2) of all water‐saving devices, only a low volume/dual‐flush toilet has a statistically significant and negative effect on water consumption; and (3) environmental concerns have a statistically significant effect on some self‐reported water‐saving behaviors. While price‐based approaches are espoused to promote economic efficiency, our findings stress that volumetric water pricing is also one of the most effective policy levers available to regulate household water consumption.
Key Points
Average water price is the best predictor of differences in h/hold consumption
Environmental attitudes do not significantly effect h/hold water consumption
Average water price is an effective lever to manage h/hold water demand
Climate change threatens biodiversity directly by influencing biophysical variables that drive species' geographic distributions and indirectly through socio-economic changes that influence land use ...patterns, driven by global consumption, production and climate. To date, no detailed analyses have been produced that assess the relative importance of, or interaction between, these direct and indirect climate change impacts on biodiversity at large scales. Here, we apply a new integrated modelling framework to quantify the relative influence of biophysical and socio-economically mediated impacts on avian species in Vietnam and Australia and we find that socio-economically mediated impacts on suitable ranges are largely outweighed by biophysical impacts. However, by translating economic futures and shocks into spatially explicit predictions of biodiversity change, we now have the power to analyse in a consistent way outcomes for nature and people of any change to policy, regulation, trading conditions or consumption trend at any scale from sub-national to global.
An incursion of Foot-and-mouth disease (FMD) in a previously FMD-free country can cause significant economic damage from immediate and prolonged closure of FMD-sensitive markets. Whilst emergency ...vaccination may help contain disease, the presence of vaccinated animals complicates post-outbreak management and the recovery of FMD-free status for return to trade. We present enhancements to the Australian Animal DISease (AADIS) model that allow comparisons of post-outbreak management strategies for vaccinated animals, for the purposes of securing the earliest possible return to trade. Two case studies are provided that compare the retention of vaccinated animals with removal for waste/salvage, and the impact on recovery of FMD-sensitive markets per OIE guidelines. It was found that a vaccinate-and-retain strategy was associated with lower post-outbreak management costs, however this advantage was outweighed by significantly higher trade losses. Under the assumptions of the study there was no cost advantage to salvaging the removed vaccinated animals.
We model game-theoretic situations in which agents motivated by Kantian ethics interact with conventional Nashian agents. We define the concept of generalized Kant–Nash equilibrium which encompasses ...the Nash equilibrium, the Kantian equilibrium and the Kant–Nash equilibrium as special cases. We show the existence and uniqueness of a Kant–Nash equilibrium in a static game of climate change mitigation, and derive its properties. In a dynamic setting, we analyze a differential game of climate change mitigation in the presence of both types of agents, and compare their Markov emission strategies. For both the static model and the dynamic model, as the population share of Kantians increases, the quality of the environment improves, and both types of agents are better off.
Differences in COVID-19 testing and tracing across countries, as well as changes in testing within each country over time, make it difficult to estimate the true (population) infection rate based on ...the confirmed number of cases obtained through RNA viral testing. We applied a backcasting approach to estimate a distribution for the true (population) cumulative number of infections (infected and recovered) for 15 developed countries. Our sample comprised countries with similar levels of medical care and with populations that have similar age distributions. Monte Carlo methods were used to robustly sample parameter uncertainty. We found a strong and statistically significant negative relationship between the proportion of the population who test positive and the implied true detection rate. Despite an overall improvement in detection rates as the pandemic has progressed, our estimates showed that, as at 31 August 2020, the true number of people to have been infected across our sample of 15 countries was 6.2 (95% CI: 4.3-10.9) times greater than the reported number of cases. In individual countries, the true number of cases exceeded the reported figure by factors that range from 2.6 (95% CI: 1.8-4.5) for South Korea to 17.5 (95% CI: 12.2-30.7) for Italy.
Purpose
The purpose of this paper is to measure the environmental performance of intensive farming and estimate agrochemical waste in physical and monetary terms. The intensive farming provides ...adverse impacts including health and environmental quality associated with the use of agrochemicals.
Design/methodology/approach
This study uses a theory of environmental efficiency that measures how efficient the farm uses agrochemical inputs. The efficiency was estimated using a set of farm-level data of intensive farming that use agrochemicals. Data were compiled from a survey of randomly selected 240 farmers who operated intensive farming in three regions of Java in 2014.
Findings
The results show that the performance of intensive farming was low. This condition caused agrochemical waste leading to the externality. Taking the external costs into account resulted in the improvement in efficiency of agrochemicals. The actual level of agrochemicals was about a hundred times higher than the most efficient level.
Research limitations/implications
This study is beyond the exogenous external costs. There is a need for a further comprehensive study to include more exogenous external costs associated with agrochemicals to have the potential value of such costs and the most socially efficient use of agrochemicals. The long-term effects of external cost to the environment and socio-economic livelihood of the farmers and other communities are considerable. Advocating for alternatives to decrease the use of detrimental agro-inputs, in the long run, will provide sound quality of the environment. Socially, both producers and consumers get the environmental and health benefits.
Practical implications
To reduce the agrochemical waste that caused environmental problems, a policy should be formulated to make farming more efficient, particularly for agrochemical use. It can be done by introducing agronomic technologies and enhancing farmers’ knowledge on environmentally friendly agriculture.
Originality/value
Environmental efficiency is able to estimate the quantity of agrochemical waste. The waste is a kind of non-point source pollution whose source and quantity are very difficult to identify and measure. As there are many definitions and measurement of environmental performance, this concept of environmental efficiency can be one of the alternatives.
A key challenge in managing semiarid basins, such as in the Murray‐Darling in Australia, is to balance the trade‐offs between the net benefits of allocating water for irrigated agriculture, and other ...uses, versus the costs of reduced surface flows for the environment. Typically, water planners do not have the tools to optimally and dynamically allocate water among competing uses. We address this problem by developing a general stochastic, dynamic programming model with four state variables (the drought status, the current weather, weather correlation, and current storage) and two controls (environmental release and irrigation allocation) to optimally allocate water between extractions and in situ uses. The model is calibrated to Australia's Murray River that generates: (1) a robust qualitative result that “pulse” or artificial flood events are an optimal way to deliver environmental flows over and above conveyance of base flows; (2) from 2001 to 2009 a water reallocation that would have given less to irrigated agriculture and more to environmental flows would have generated between half a billion and over 3 billion U.S. dollars in overall economic benefits; and (3) water markets increase optimal environmental releases by reducing the losses associated with reduced water diversions.
Key Points
Method to quantify the tradeoffs between competing uses
Method to optimize water allocation decisions
Importance of pulse events when generating environmental flows
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