Additional Ton Research Articles

Estimates of the Social Cost of Carbon: Concepts and Results from the DICE-2013R Model and Alternative Approaches

The social cost of carbon (SCC) is an important concept for understanding and implementing climate change policies. This term represents the economic cost caused by an additional ton of carbon dioxide emissions (or more succinctly carbon) or its equivalent. The present study describes the development of the concept, provides examples of its use in current US regulator policies, examines its analytical background, and estimates the SCC using an updated integrated assessment model, the DICE-2013R model. The study estimates that the SCC is $18.6 per ton of CO2 in 2005 US dollars and international prices for the current period (2015). For the central case, the real SCC grows at 3% per year over the period to 2050. The major open issues concerning the SCC continue to be the appropriate discount rate, the potential for catastrophic damages, the impact of incomplete harmonization of abatement policies, and the effects of distortionary taxes.

Agreeing to disagree on climate policy

Disagreements about the value of the utility discount rate--the rate at which our concern for the welfare of future people declines with their distance from us in time--are at the heart of the debate about the appropriate intensity of climate policy. Seemingly small differences in the discount rate yield very different policy prescriptions, and no consensus "correct" value has been identified. We argue that the choice of discount rate is an ethical primitive: there are many different legitimate opinions as to its value, and none should receive a privileged place in economic analysis of climate policy. Rather, we advocate a social choice-based approach in which a diverse set of individual discount rates is aggregated into a "representative" rate. We show that performing this aggregation efficiently leads to a time-dependent discount rate that declines monotonically to the lowest rate in the population. We apply this discounting scheme to calculations of the social cost of carbon recently performed by the US government and show that it provides an attractive compromise between competing ethical positions, and thus provides a possible resolution to the ethical impasse in climate change economics.

Calculating total urban forest volume considering the carbon cycle in an urban area – focusing on the city of Chuncheon in South Korea.

With the recent threat of climate change, the issue of carbon emission mitigation has become one of the fastest growing international agendas. The major cause of pan-international climate change is the increase of CO2 intensity in the atmosphere. It is possible, nonetheless, to sustain the carbon cycle when green plants, the only organic sink, exist in proper quantity. The main purpose of this current study is to quantitatively analyze the urban forest volume required to absorb carbon from a densely populated area. The study calculates CO2 emissions and uptake by urban forest volume in a given area, as well as the total urban forest volume required to absorb all of the emitted CO2. In a survey in the city of Chuncheon, the volume of CO2 emissions and that of the CO2 that can be absorbed was 2,211,586.74 and 30,455.48 tons, respectively, which means that approximately 2,181,129.26 additional tons need to be absorbed by urban forest volume. By the second-grade vegetation standard, it is necessary to secure 101,921.93 ha of coniferous forest, 103,371.06 ha of broad-leaved forest, or 103,863.30 ha of mixed forest. The urban area within the city of Chuncheon covers only 5303.04 ha, which clearly implies that urban forest alone cannot absorb the CO2 emissions in the area. Therefore, it follows that additional mitigation efforts need to be taken along with securing as much urban forest as possible.

The social cost of CO2 in a low-growth world

Climate change mitigation has slowed down as major emitters face economic stagnation. Research now shows that the average cost to society of an additional tonne of carbon dioxide emissions tends to increase during recessions as the impact occurs in a poorer world. This suggests that climate change mitigation should be a priority in a low-growth situation.

Assessing costs of soil carbon sequestration by crop-livestock farmers in Western Australia

Carbon sequestration in agricultural soil has been identified as a potential strategy to offset greenhouse gas emissions. Within the public debate, it has been claimed that provision of positive incentives for farmers to change their land management will result in substantial carbon sequestration in agricultural soils at a low carbon price. However, there is little information about the costs or benefits of carbon sequestration in agricultural soils to test these claims. In this study, the costeffectiveness of alternative land-use and land-management practices that can increase soil carbon sequestration is analysed by integrating biophysical modelling of carbon sequestration with wholefarm economic modelling. Results suggest that, for a case study model of a crop-livestock farm in the Western Australian wheatbelt, sequestering higher levels of soil carbon by changing rotations (to include longer pasture phases) incur considerable opportunity costs. Under current commodity prices, farmers would forego more than $80 in profit for every additional tonne of CO2-e stored in soil, depending on their adoption of crop residue retention practices. This is much higher than the initial carbon price of $23t−1 in Australia’s recently legislated carbon tax. This analysis does not incorporate the possibility that greenhouse gas emissions may increase as a result of including longer pasture phases. Accounting for emissions may substantially reduce the potential for net carbon sequestration at low carbon prices.

Rules of thumb for minimizing subsoil compaction

AbstractSubsoil compaction is persistent and can affect important soil functions including soil productivity. The aim of this study was to develop recommendations on how to avoid subsoil compaction for soils exposed to traffic by machinery at field capacity. We measured the vertical stress in the tyre–soil contact area for two traction tyres at ca. 30‐ and 60‐kN wheel loads on a loamy sand at field capacity. Data on resulting stress distributions were combined with those from the literature for five implement tyres tested at a range of inflation pressures and wheel loads. The vertical stress in the soil profile was then predicted using the Söhne model for all tests in the combined data set. The predicted stress at 20 cm depth correlated with the maximum stress in the contact area, tyre inflation pressure, tyre–soil contact area and mean ground pressure. At 100 cm depth, the predicted vertical stress was primarily determined by wheel load, but an effect of the other factors was also detected. Based on published recommendations for allowable stresses in the soil profile, we propose the ‘50‐50 rule’: At water contents around field capacity, traffic on agricultural soil should not exert vertical stresses in excess of 50 kPa at depths >50 cm. Our combined data provide the basis for the ‘8‐8 rule’: The depth of the 50‐kPa stress isobar increases by 8 cm for each additional tonne increase in wheel load and by 8 cm for each doubling of the tyre inflation pressure. We suggest that farmers use this simple rule for evaluating the sustainability of any planned traffic over moist soil.

Climate Risks and Carbon Prices: Revising the Social Cost of Carbon

AbstractThe social cost of carbon – or marginal damage caused by an additional ton of carbon dioxide emissions – has been estimated by a U.S. government working group at $21/tCO2in 2010. That calculation, however, omits many of the biggest risks associated with climate change, and downplays the impact of current emissions on future generations. Our reanalysis explores the effects of uncertainty about climate sensitivity, the shape of the damage function, and the discount rate. We show that the social cost of carbon is uncertain across a broad range, and could be much higher than $21/tCO2. In our case combining high climate sensitivity, high damages, and a low discount rate, the social cost of carbon could be almost $900/tCO2in 2010, rising to $1,500/tCO2in 2050.The most ambitious scenarios for eliminating carbon dioxide emissions as rapidly as technologically feasible (reaching zero or negative net global emissions by the end of this century) require spending up to $150 to $500 per ton of reductions of carbon dioxide emissions by 2050. Using a reasonable set of alternative assumptions, therefore, the damages from a ton of carbon dioxide emissions in 2050 could exceed the cost of reducing emissions at the maximum technically feasible rate. Once this is the case, the exact value of the social cost of carbon loses importance: the clear policy prescription is to reduce emissions as rapidly as possible, and cost-effectiveness analysis offers better insights for climate policy than costbenefit analysis.

Mechanism Analysis of Indigenous Microbial Enhancement for Residue Oil Recovery

Biotechnological nutrient flooding was applied to the North block of the Kongdian Oilfield during 2001-2005. The biotechnology involved the injection of a water-air mixture made up of mineral nitrogen and phosphorous salts with the intent of stimulating the growth of indigenous microorganisms. During monitoring of the physico-chemical, microbiological and production characteristics of the North block of the Kongdian bed, it was revealed significant changes took place in the ecosystem as a result of the technological treatment. The microbial oil transformation was accompanied by an accumulation of carbonates, lower fatty acids and biosurfactants in water formations, which is of value to enhanced oil recovery. The microbial metabolites changed the composition of the water formation, favored the diversion of the injected fluid from closed, high permeability zones to upswept zones and improved the sweep efficiency. The results of the studies demonstrated strong hydrodynamic links between the injection wells and production wells. Microbiological monitoring of the deep subsurface ecosystems and the filtration properties of the fluids are well modified, producing 40000 additional tons of oil in the test areas.

Climate change report calls for iterative risk management framework

Climate change is occurring, is very likely caused by human activities, and poses significant risks for a broad range of human and natural systems, a 12 May report by the U.S. National Research Council (NRC) reaffirms. The report includes a series of recommended steps to respond to those risks. In addition, the report urges an iterative risk management framework that can adapt to new information and changing circumstances and concerns about the risks. “Each additional ton of greenhouse gases emitted commits us to further change and greater risks. In the judgment of the [NRC] Committee on America's Climate Choices, the environmental, economic, and humanitarian risks of climate change indicate a pressing need for substantial action to limit the magnitude of climate change and to prepare to adapt to its impacts,” the report states.

Climate Risks and Carbon Prices: Revising the Social Cost of Carbon

The social cost of carbon - or marginal damage caused by an additional ton of carbon dioxide emissions - has been estimated by a U.S. government working group at $21 in 2010. That calculation, however, omits many of the biggest risks associated with climate change, and downplays the impact of our current emissions on future generations. Our reanalysis explores the effects of uncertainty about climate sensitivity, the shape of the damage function, and the discount rate. We show that the social cost of carbon is uncertain across a broad range, and could be much higher than $21. In our worst case, it could be almost $900 in 2010, rising to $1,500 in 2050. The most ambitious scenarios for eliminating carbon dioxide emissions as rapidly as technologically feasible (reaching zero or negative net global emissions by the end of this century) require spending up to $150 to $500 per ton of reductions in carbon dioxide emissions by 2050. Using a reasonable set of alternative assumptions, therefore, the damages from a ton of carbon dioxide emissions in 2050 could exceed the cost of reducing emissions at the maximum technically feasible rate. Once this is the case, the exact value of the social cost of carbon loses importance: the clear policy prescription is to reduce emissions a rapidly as possible, and cost-effectiveness analysis offers better insights for climate policy than cost-benefit analysis.

Estimates of the Social Cost of Carbon: Background and Results from the Rice-2011 Model

A new and important concept in global warming economics and policy is the social cost of carbon or SCC. This concept represents the economic cost caused by an additional ton of carbon-dioxide emissions or its equivalent. The present study describes the development of the concept as well as its analytical background. We estimate the SCC using an updated version of the RICE-2011 model. Additional concerns are uncertainty about different aspects of global warming as well as the treatment of different countries or generations. The most important results are: First, the estimated social cost of carbon for the current time (2015) including uncertainty, equity weighting, and risk aversion is $44 per ton of carbon (or $12 per ton CO_{2}) in 2005 US$ and international prices). Second, including uncertainty increases the expected value of the SCC by approximately 8 percent. Third, equity weighting generally tends to reduce the SCC. Finally, the major open issue concerning the SCC continues to be the appropriate discount rate.

Influence of EDC Cracking Severity on the Marginal Costs of Vinyl Chloride Production

The selectivity of the EDC (1,2-dichloroethane) cracking process in vinyl chloride monomer (VCM) manufacturing strongly depends on the cracking severity and the EDC feed quality. A strong decline of selectivity is observed for EDC feed purities below 99.5 wt % or cracking rates above approximately 60%. The selectivity of the cracking process also deteriorates in the course of the plant’s operating time as a result of accelerated coke formation. Reduced selectivity in the process of EDC cracking results in increased marginal costs (additional costs per each additional tonne of VCM). This is especially relevant for a VCM plant running near full load. The marginal costs can be expressed as a function of the cracking rate and the resulting costs for processing the uncracked portion of EDC. With a new and simplified EDC cracking simulation model for the energy input and conversion, together with a simplified reaction model for the definition of the corresponding product spectrum, the cost impact of the aforementioned influences on the cracking process can be estimated in advance based on the current production rate and plant performance.

Pasture and forage crop systems for non-irrigated dairy farms in southern Australia. 1. Physical production and economic performance

The dairy industry in southern Australia relies on perennial ryegrass pasture to supply 60–70% of the diet of lactating cows. Improvements in the amount and quality of home-grown forage used for dairy cow feeding are critical for further productivity gains in the industry. A modeling approach was used to estimate the effects of changing the forage system on farm business profit. Base models (using 100% of farm area in perennial ryegrass pasture) were constructed for above-average (Top 40%) and high performing (Top 10%) farm types typical of two locations: Terang in southwest Victoria and Ellinbank in Gippsland, eastern Victoria. These models were then re-simulated using different forage base options such as: oversowing annual ryegrass, winter crops (annual ryegrass monoculture, winter cereal grown for whole crop silage), summer crops (grazing brassicas, maize), combinations of these (double cropping), or summer shoulder pasture (notionally based on tall fescue) on between 10% and 100% of farm area. Estimated total home-grown forage consumption ranged between 6.7 and 10.2 t DM/ha/year for Terang and 7.8 and 11.9 t DM/ha/year for Ellinbank. Within farm types at Terang, the amount of home-grown forage consumed explained between 30% and 45% of the variation in operating profit. The models predicted that profit improvements of $70–$100 per hectare per additional tonne of home-grown forage consumed are possible from changing the forage base. Oversowing annual ryegrass led to greater forage supply, but only at times when pasture availability was largely adequate to meet current herd requirements therefore additional feed was not used as cost-effectively as other options. By contrast, the summer shoulder pasture type shifted the seasonal distribution of forage supply further into summer compared to perennial ryegrass, and led to higher amounts of pasture in the diet and greater profitability. Double cropping systems also appeared capable of increasing operating profit and total home-grown forage consumption. Increasing home-grown forage consumption and profit by using some of the alternative pastures and forage crops investigated here requires better information on crop/pasture agronomy, management and feeding, and greater decision-making and management input compared to current systems.

Measuring the damages of air pollution in the United States

This paper measures the damages due to emissions of air pollution in the United States. An integrated assessment model is used to calculate the marginal damage associated with emitting an additional ton of pollution from nearly 10,000 sources in the U.S. The total damage produced by a source is the marginal damage of an emission, its shadow price, times the total tons emitted from a specific source. Adding total damages across all sources yields gross annual damages (GAD) which is a green accounting parallel to gross domestic product (GDP). GAD in 2002 varies between $71 billion and $277 billion (0.7–2.8% of GDP). The range of values depends largely on the value of health and the concentration–response function relating exposures to fine particulate matter (PM 2.5) to adult mortality rates. Source location also matters. Urban emissions constitute 52% of total emissions by weight yet they cause nearly three-quarters of the GAD.

Forage supply systems for dryland dairy farms in southern Australia

Continued improvements in home grown forage consumption are needed to support the long-term profitability of the dairy industry in southern Australia. Most home grown forage currently comes from perennial ryegrass pastures, which have significant limitations in the southern Australia environment. These limitations threaten future productivity gains, and we therefore consider opportunities for using other plant species. Data on the production of alternative perennial grasses, brassica summer crops, C4 summer crops and winter cereals grown for whole-crop silage are limited and generally show large variation in yields between sites and years. Simulation models suggest that, once the base ryegrass pasture is well-utilised, incorporating complementary forages can return $70 - $100/ha extra operating profit for every additional tonne of home grown forage DM consumed per ha. Double cropping (winter cereal or annual ryegrass followed by a summer crop of turnips or maize) and summer-active pastures such as tall fescue show particular promise. Further information is required on how to integrate these forages into whole farm feeding systems to realise the additional profit with manageable business and environmental risk. Keywords: dairy systems, forage production, pastures, forage crops, simulation models

The economic impact of the ACFM catch options for the Danish North Sea herring and industrial fisheries in 1999

Abstract A model to calculate the short-term economic net revenue to fisheries constrained by quotas on both target and catch species is presented and applied to the Danish herring- and industrial fisheries in 1999. For this year the ICES Advisory Committee on Fisheries Management (ACFM) presented seven management options for North Sea herring differing in the shares allocated to directed herring fishery for human consumption purposes and to by-catch in the industrial fisheries respectively. For each ACFM option the net revenues to each fleet segment are estimated in two scenarios: one assuming that the Danish fisheries are constrained by the EU regulations alone and one in which the fleets in addition to the EU regulations are constrained by additional national regulations on quota distribution on fleet segments. The results suggest that there is little difference (about 4%) in the net revenue accruing from the different ACFM options and that the total net revenue under combined EU and Danish regulation is about 8% less than would be possible under optimal effort allocation with the EU regulation alone. Furthermore, the added value of an additional tonne of herring on the overall human consumption quota is, under optimal effort allocation but still respecting the EU-Norway agreement, estimated to be about DKK 540 (€72).

The economic impact of the ACFM catch options for the Danish North Sea herring and industrial fisheries in 1999

A model to calculate the short-term economic net revenue to fisheries constrained by quotas on both target and catch species is presented and applied to the Danish herring- and industrial fisheries in 1999. For this year the ICES Advisory Committee on Fisheries Management (ACFM) presented seven management options for North Sea herring differing in the shares allocated to directed herring fishery for human consumption purposes and to by-catch in the industrial fisheries respectively. For each ACFM option the net revenues to each fleet segment are estimated in two scenarios: one assuming that the Danish fisheries are constrained by the EU regulations alone and one in which the fleets in addition to the EU regulations are constrained by additional national regulations on quota distribution on fleet segments. The results suggest that there is little difference (about 4%) in the net revenue accruing from the different ACFM options and that the total net revenue under combined EU and Danish regulation is about 8% less than would be possible under optimal effort allocation with the EU regulation alone. Furthermore, the added value of an additional tonne of herring on the overall human consumption quota is, under optimal effort allocation but still respecting the EU-Norway agreement, estimated to be about DKK 540 (€72).

The cost of sequestering carbon on private forest lands

The increase of carbon dioxide in the atmosphere and its possible greenhouse effect on global climate has become one of today's major environmental issues. Utility/coal companies which produce high levels of carbon dioxide are interested in mitigating their emissions by sequestering carbon in trees. This study proposed to investigate the amount of money that utility companies would have to pay private forest landowners to sequester additional tonnes of carbon in their forests. Analyses were conducted to calculate the annual financial compensation/incentives necessary to (1) compensate forest landowners who apply economically sub-optimal rotations to sequester maximum carbon; or (2) motivate private landowners to convert unstocked lands into productive forest lands to sequester carbon. Biological and financial analyses were conducted using Loblolly pine ( Pinus taeda) on a range of site indices. Applying the Faustmann formula, the amount of necessary compensation/incentive was calculated as the difference between the soil expectation value (SEV) of the economically optimal rotation and the SEV of the biologically optimal rotation which maximizes mean annual increment (MAI) of sawtimber and, therefore, maximizes carbon stored in the forest and in the long-lived wood products. Results indicate that the carbon sequestration difference between the MAI of the optimal economic rotation and that of the optimal carbon rotation may be up to 0.79 t of carbon per hectare. Planting unstocked land may store an additional 1.03–3.77 t of carbon per hectare per year. The annual compensation values tend to increase as real interest rates increase. The minimum annual compensation is $0.84 per hectare using an interest rate of 2.5% on site index 50 land. The maximum annual compensation is $72.79 per hectare using an interest rate of 12.5% on site index 90 land. The average costs of sequestering an additional tonne of carbon on lands already intensively managed vary from $4.18 to $181.27. The average costs of sequestering an additional tonne of carbon on unstocked land range from $0.74 to $27.32.

The advent of "green" computer design

Computer manufacturing and consumption are becoming a significant environmental concern. Some fundamental changes are beginning to take place in the computer industry. These changes aren't about MIPS or megabytes. They're about manufacturers in the computer industry beginning to look for ways to reduce the resources they consume and the waste they generate, and for ways to make their products more recyclable. This process is known as computer design. One factor driving green design is the fact that computer manufacturing and consumption is growing rapidly and is becoming a significant cause for environmental concern. For example, semiconductor manufacturing is very resource-intensive: making just one wafer requires substantial amounts of energy, photochemicals, acids, hydrocarbon based solvents, and other materials. Meanwhile, computers are also creating a waste disposal problem. Based on current consumption pattern, IBM estimates that discarded computers will occupy 2 million tons of US landfill space by 2000. Making components, etching circuit boards, and other manufacturing processes generate additional tons of waste. Green computer design addresses four primary issues: reducing the resources consumed and the waste generated when producing computers or components; developing cleaner manufacturing processes; minimizing the energy and other resources that computers consume; and enabling computers and components to be used (and thereby stay out of the waste stream) longer.

Limestone to Mitigate Lake acidification: macrozoobenthos response in treated and reference lakes

The littoral macrozoobenthos (MZB) of two low acid neutralizing capacity (ANC = ≤ 50.0 µeq l−1) northeastern Pennsylvania lakes (treatment and reference) were sampled each ice free season, 1984 through 1988, to evaluate response to limestone addition. Following addition of 100 tons agricultural limestone (CaCO3) to the treatment lake in February 1985, mean annual ANC rose from 20 µeq l−1 to 668 µeq l−1 then decreased. In October 1987, ANC in the treatment lake was decreasing, so 15 additional tons of limestone were added. Pre- limestoning there were few significant (p<0.05) differences between MZB assemblages in the two lakes, but 4 years post treatment the following differences (p<0.05) were detected in the treatment lake: more Chironomidae, Ephemeroptera, Odonata, Hyalella azteca, total MZB numbers and higher Mollusca wet weight than in the reference lake. From 1984 to 1988 in the treatment lake the annual means of the following community characteristics increased (p<0.05): totals of Chironomidae, Ephemeroptera (including Caenis spp.), Odonata, Trichoptera, Sphaeriidae, collectors and MZB numbers; Chironomidae and Ephemeroptera taxa richness and total taxa richness; total and Mollusca wet weight. However, the treatment lake ecosystem is neither self-sustaining nor stable because limestone must be added every 2 to 3 years to maintain ANC above 50 µeq l−1 In the reference lake annual means of ANC, specific conductance, calcium and magnesium decreased (p<0.05) while Secchi depth increased (p<0.05), suggesting continuing acidification.