The importance of ‘extremely unlikely’ events: tail risk and the costs of climate change

In assessing the risks associated with climate change, ‘tail risks’ (low‐probability extreme events) often play a much larger role than their probability alone might indicate. There are three main reasons for this: the linear relationship between sensitivity and warming; the convexity of the damage function; and the concavity of the utility function. Ignoring the upper tail of the distribution of possible outcomes will result in serious underestimates of the social cost of carbon dioxide (CO₂) emissions and of the socially optimal price for emissions.     

Agriculture's Likely Role in Meeting Canada's Kyoto Commitments*

Voluntary adoption of beneficial management practices will be the primary means by which farmers cut net greenhouse gas (GHG) emissions. The offset system will not be a major driver due to (a) the relatively low prices likely to be offered by large final emitters facing an emission cap, (b) discounts applied to those prices for temporary sequestration, (c) the transaction costs and risk premiums associated with signing carbon contracts, and (d) the low elasticity of supply of CO₂ abatement. Although Canadian farmers are likely to participate to only a limited extent in the carbon‐offset market, many will find it profitable to adopt one or more of the BMPs for reducing net GHG emissions. Canadian agriculture is likely to contribute significantly to net emission reductions by voluntarily sequestering carbon due to the adoption of zero till in the last decade, and possibly by cutting fertilizer levels in the next decade. The contribution will be mainly a response to meeting personal economic objectives rather than being induced by direct incentives through the offset program.     

Allocating provincial CO2 quotas for the Chinese national carbon program

In order to improve the efficiency of climate change initiatives China launched its national carbon market in December 2017. Initial CO2 quota allocations are a matter of significant concern. How should we allocate CO₂ emissions reduction responsibilities among Chinese provinces, assuming that provinces will not or cannot trade these responsibilities among themselves? In this paper, we allocate CO₂ quota from the perspective of cost minimisation. First, we estimate the national CO₂ marginal abatement cost (MAC) function and deduce the interprovincial MAC functions. Second, we build an allocation model with nonlinear programming for cost minimisation. Finally, we obtain the allocation results under the emissions reduction target by 2030. The results are as follows. (i) The national MAC was 134.3 Yuan/t (at the constant price of 1978) in 2011, with an overall upward trend from 1990 to 2011. (ii) The interprovincial MACs differ significantly and decline gradually from east to west. Hebei has the largest emissions reduction quota, and Shandong has the largest emissions quota by 2030. (iii) Compared with other criteria of per capita, gross domestic product (GDP), grandfathering and carbon intensity, the proposed approach is the most cost‐effective in achieving the reduction target, with cost savings of 37.7, 34.5, 47.9 and 33.87 per cent, respectively.     

Non‐Parametric Modelling of CO2 Emission Quota

Dutch glasshouse firms are facing the introduction of a system of tradable CO₂ emission quotas. This paper employs a non‐parametric method for modelling tradable CO₂ emissions of Dutch glasshouse firms. The method is capable of generating shifts in CO₂ emissions across the sample of firms. Moreover, changes in volumes of outputs produced and inputs used are computed. Results show that firms using a conventional heating technology will be net purchasers of CO₂ emissions, whereas firms using more advanced heating technologies will sell part of their emission quota.     

Climate change: a rational choice politics view*

Reduction in carbon dioxide emissions constitutes a global public good; and hence there will be strong incentives for countries to free ride in the provision of CO₂ emission reductions. In the absence of more or less binding international agreements, we would expect carbon emissions to be seriously excessive, and climate change problems to be unsolvable. Against this obvious general point, we observe many countries acting unilaterally to introduce carbon emission policies. That is itself an explanatory puzzle, and a source of possible hope. Both aspects are matters of ‘how politics works’– i.e. ‘public choice’ problems are central. The object of this paper is to explain the phenomenon of unilateral policy action and to evaluate the grounds for ‘hope’. One aspect of the explanation lies in the construction of policy instruments that redistribute strategically in favour of relevant interests. Another is the ‘expressive’ nature of voting and the expressive value of environmental concerns. Both elements – elite interests and popular (expressive) opinion – are quasi‐constraints on politically viable policy. However, the nature of expressive concerns is such that significant reductions in real GDP are probably not sustainable in the long term – which suggests that much of the CO₂ reduction action will be limited to modest reductions of a largely token character. In that sense, the grounds for hope are, although not non‐existent, decidedly thin.     

Policy options towards deforestation reduction in Cameroon: An analysis based on a systematic approach

This study advances measures that can combat deforestation in Cameroon. It also looks at possible carbon dioxide (CO₂) emission reductions and the effects on gross domestic product (GDP) and employment based on selected baseline scenarios based on reductions in deforestation. A systematic approach of analyzing the drivers, agents, socio-economic context, political context, spatial context of deforestation and specific and general deforestation reduction policies is used. The final step of the approach is to verify the repercussions of deforestation reduction on CO₂ emissions, employment and GDP. Monitoring population growth and arable production through intensification of production is promising. The general policies that this study postulates are enforcement, legal adherence, specification of tasks and quotas, collaboration, forest licensing and monitoring. More specific policies could be within the reduction of emissions from deforestation and forest degradation mechanism (REDD+) as well as diversification of livelihoods, mechanization, use of fertilizers and intensive cattle farming inter alia. Reductions in deforestation will reduce atmospheric CO₂, employment in the forestry sector and the share of forestry's contribution to GDP.     

The regional economic effects of a reduction in carbon emissions

Concern about climate change has led to policy to reduce CO₂ emissions although it is likely that policy will have differential regional impacts. While regional impacts will be politically important, very little analysis of them has been carried out. This paper contributes to the analysis of this issue by building a small model involving two regions, incorporating the right to emit CO₂ as a factor of production with the level of permitted emissions set by the national government. We argue that there is likely to be pressure on governments to use other policies to offset the possible adverse regional economic consequences of the pollution‐reduction policy; we also consider a range of such policies. Using numerical simulation, we find that a 10 per cent reduction has relatively small but regionally differentiated economic effects. Standard fiscal policies are generally ineffective or counterproductive while labour market policies are more useful in offsetting the adverse effects.     

The Impact of FDI on CO2 Emissions in Latin America

This paper uses panel Granger causality tests to study the relationship between sector-specific foreign direct investment (FDI) and CO₂ emissions. Using a sample of 18 Latin American countries for the period 1980–2007, we find causality running from FDI in pollution-intensive industries (“the dirty sector”) to CO₂ emissions per capita. This result is robust to controlling for other factors associated with CO₂ emissions and using the ratio of CO₂ emissions to GDP. For other sectors, we find no robust evidence that FDI causes CO₂ emissions.     

Marginal Abatement Cost Curves for UK Agricultural Greenhouse Gas Emissions

This article addresses the challenge of developing a ‘bottom‐up’ marginal abatement cost curve (MACC) for greenhouse gas (GHG) emissions from UK agriculture. An MACC illustrates the costs of specific crop, soil and livestock abatement measures against a ‘business as usual’ scenario. The results indicate that in 2022 under a specific policy scenario, around 5.38 Mt CO₂ equivalent (e) could be abated at negative or zero cost. A further 17% of agricultural GHG emissions (7.85 Mt CO₂e) could be abated at a lower unit cost than the UK Government’s 2022 shadow price of carbon [£34 (tCO₂e)^?1]. The article discusses a range of methodological hurdles that complicate cost‐effectiveness appraisal of abatement in agriculture relative to other sectors.     

Green Light for Green Agricultural Policies? An Analysis at Regional and Global Scales

This paper analyses the effects of introducing biodiversity‐targeted ecological focus area (EFA) requirements on all farms with arable land in the EU by quantifying their global, regional, economic and environmental impacts in a mutually consistent way. To capture these impacts, different spatial scales need to be considered – ranging from on‐farm decisions regarding the EFA in the EU, to supply response around the world. In order to address this challenge, we combine the supply side of the CAPRI model, which offers high spatial, farm and policy resolution in the EU, with the GTAP model of global trade and land use. Both models are linked through a multi‐product, restricted‐revenue function for the EU crop sector. The results predict improved environmental status in the high‐yielding regions of the EU. However, output price increases lead to intensification in the more marginal areas of the EU where little or no additional land is taken out of production. The decrease in arable land in the EU is partially compensated by an increase of crop land, as well as increased fertiliser applications, in other regions of the globe. Thus, the improvement of environmental status in the EU comes at the price of global intensification, as well as the loss of forest and grassland areas outside the EU. Overall, we find that every hectare of land that is taken out of production in the EU increases greenhouse gas emissions in the rest of the world by 20.8 tonnes CO₂ equivalent.     

Intra-Country Health Inequalities and Air Pollution in Developing Countries

In the health economics literature, many studies have assessed the association between environmental degradation and health outcomes. This paper extends this literature by investigating how the presence of air pollution might explain health inequalities both between and within developing countries. We argue that differential exposure to air pollution between asset classes, differential ability to prevent the negative health effects of environment degradation, differential capacity to respond to disease caused by pollutants, and particular susceptibility of some groups to the effects of air pollution are all sufficient reasons for explaining a positive link between air pollution and asset-related health inequality. Using data from developing countries, our econometric results show that sulphur dioxide emissions (SO₂) and particulate matter (PM₁₀) partly explain the large disparities in infant and child mortalities between and within developing countries. In addition, we found that the institutions that are based on democratic principles, and which have low levels of corruption and high quality bureaucracy, are the most effective. That is, they are more responsive to the needs of the poor, they promote access to justice and public administration, and they deliver basic services to those most in need. As a result, they are able to more effectively mitigate the mortality effect of pollution for the poorest asset classes compared with that of the richest ones and thus reduce the health inequality it provokes.     

Modelling the transportation of primary aggregates in England and Wales: Exploring initiatives to reduce CO2 emissions

Millions of tonnes of aggregates are transported across England and Wales each year, which causes constant concerns in regard to CO₂ emissions. Much of that concern arises out of the long journeys from quarries to construction sites, and the fact that the main mode of transfer is by road. The aim of this paper is to describe the construction of a spatial decision support system (SDSS) to examine the impacts of scenarios to reduce the level of CO₂ emissions. The SDSS is made up of a GIS containing a set of spatial models (including a spatial interaction model and a microsimulation model) underpinned by a detailed transport network of road and rail routes across England and Wales. The spatial interaction models are first calibrated to reproduce the existing set of flows of aggregates between quarries and local authority districts. The distance decay component is the travel distance equivalent across the road and rail networks. Based on these flows, linear models can be set up to estimate the amount of CO₂ emissions associated with the existing set of flows. Then a series of what-if scenarios are set up which look at how changes in any part of the geography of production, the level of demand in certain areas or the transport process will impact the CO₂ emissions. The paper demonstrates the capability of the SDSS in responding to the various spatial policies applied in different stages of the supply chain of the aggregates markets.     

Logs or permits? Forestry land use decisions in an emissions trading scheme

Negative carbon emissions options are required to meet long-term climate goals in many countries. One way to incentivise these options is by paying farmers for carbon sequestered by forests through an emissions trading scheme (ETS). New Zealand has a comprehensive ETS, which includes incentives for farmers to plant permanent exotic forests. This research uses an economy-wide model, a forestry model and land use change functions to measure the expected proportion of farmers with trees at harvesting age that will change land use from production to permanent forests in New Zealand from 2014 to 2050. We also estimate the impacts on carbon sequestration, the carbon price, gross emissions, GDP and welfare. When there is forestry land use change, the results indicate that the responsiveness of land owners to the carbon price has a measured impact on carbon sequestration. For example, under the fastest land use change scenario, carbon sequestration reaches 29.93 Mt CO₂e by 2050 compared to 23.41 Mt CO₂e in the no land use change scenario (a 28% increase). Even under the slowest land use change scenario, carbon sequestration is 25.89 Mt CO₂e by 2050 (an 11% increase compared with no land use change). This is because, if foresters decide not to switch to permanent forests in 1 year, carbon prices and ultimately incentives to convert to permanent forests will be higher in future years.     

Dairy sheep farms in semi-arid rangelands: A carbon footprint dilemma between intensification and land-based grazing

In recent decades there have been significant changes in land use and production orientation in certain marginal agricultural areas in the southwest of Spain. The abandonment of rainfed cereal crops and their change of use as natural pastures grazed by milk sheep, have led to an improvement in the profitability of the farms, greater industrialisation and a positive impact on rural development.This paper calculates the carbon footprint (CF) of farms in the context of life cycle assessment with the objective to identify the system that accounts for the lowest CF while maintaining adequate levels of profitability and revitalising the rural environment. The data were obtained through surveys carried out on dairy sheep farms of different typologies, ranging from the semi-intensive farms with small grazing areas, to the extensive farms with large areas of natural pastures. Findings could help farmers evaluate the environmental impact of their activities, while at the same time provide consumers with valuable evidence to be used in further marketing actions.Greenhouse gas emissions vary from 1.77 to 4.09 Kg CO₂eq/kg of milk, where the lowest values correspond to the most intensive farms and the highest values to the most extensive and least productive farms. Enteric fermentation, followed by feeding, are the emissions with the greatest impact. Enteric fermentation reaches its maximum value (52.22 % of the total emissions) in the most extensive farms.On other hand, this study found that carbon sequestration varies between 0.09 and 2.04 kg of CO₂eq/kg of milk, a figure that can considerably reduce the carbon footprint calculation and justifies its inclusion in the Life Cycle Assessment.     

The right place to grow rice for the Japanese market: comparative analysis of greenhouse gas emissions of rice cultivation in Japan and the United States

One consequence of increasing agricultural trade is a shift of geographic location of agricultural activity to more economically productive countries. Whether or not the economic efficiency translates to environmental efficiency for agricultural goods is an open question. To examine environmental implications of shifting agricultural location, we analysed the life-cycle greenhouse gas (GHG) emissions of rice production in Japan and the US for the Japanese market in a comparative manner. This paper presents the life-cycle assessment of brown japonica rice. Our computation of GHG emissions of rice production in Japan and the US were 3.54 and 2.99?kgCO₂-eq kg-rice^?1, respectively. With respect to harvested area, the emissions were 18.4 in Japan and 27.8?tCO₂-eq ha^?1 in the US. For Japan to be environmentally competitive with the US production, fundamental restructuration of field size is necessary to increase yield. In conclusion, economic efficiency does not translate to environmental efficiency with the case of rice production. Importing rice is both economically and environmentally viable option for the Japanese market.     

Warming temperatures will likely induce higher premium rates and government outlays for the U.S. crop insurance program

Likely climate change impacts include damages to agricultural production resulting from increased exposure to extreme heat. Considerable uncertainty remains regarding impacts on crop insurance programs. We utilize a panel of U.S. corn yield data to predict the effect of warming temperatures on the mean and variance of yields, as well as crop insurance premium rates and producer subsidies. While we focus on corn, we demonstrate that the subsidy impacts are likely to carry over to other major program crops. We find that warming decreases mean yields and increases yield risk on average, which results in higher premium rates. Under a 1°C warming scenario, we find that premium rates at the 90% coverage level will increase by 39% on average; however, there is considerable statistical uncertainty around this average as the 95% confidence interval spans from 22% to 61%. We also find evidence of extensive cross‐sectional differences as the county‐level rate impacts range from a 10% reduction to a 63% increase. Results indicate that exposure to extreme heat and changes in the coefficient of variation are large drivers of the impacts. Under the 1°C warming scenario, we find that annual subsidy payments for the crop insurance program could increase by as much as $1.5 billion, representing a 22% increase relative to current levels. This estimate increases to 3.7 billion (57%) under a 2°C warming scenario. Our results correspond to a very specific counterfactual: the marginal effect of warming temperatures under current technology, production, and crop insurance enrollments. These impacts are shown to be smaller than the forecasted impacts under a commonly used end‐of‐century general circulation model for even the most optimistic CO₂ emissions projection.     

Agriculture and global climate stabilization: a public good analysis

The stabilization of global climate presents one of the most complex problems in public good provision the world has faced. Continuation of “business as usual” policies, leading to warming of more than 2 degrees over the next year, will produce significant damage to agricultural systems and catastrophic damage to the natural ecosystems that ultimately support agriculture. The best solution to the public goods problem is a “contract and converge” agreement in which the ultimate outcome is a common global entitlement to CO₂ emissions per person.     

Managing increasing environmental risks through agrobiodiversity and agrienvironmental policies

Agrobiodiversity can provide natural insurance to risk‐averse farmers by reducing the variance of crop yield, and to society at large by reducing the uncertainty in the provision of public‐good ecosystem services, for example, CO₂ storage. We analyze the choice of agrobiodiversity by risk‐averse farmers who have access to financial insurance, and study the implications for agrienvironmental policy design when on‐farm agrobiodiversity generates a positive risk externality. While increasing environmental risk leads private farmers to increase their level of on‐farm agrobiodiversity, the level of agrobiodiversity in the laissez‐faire equilibrium remains inefficiently low. We show how either one of the two agrienvironmental policy instruments can cure this risk‐related market failure: an ex ante Pigouvian subsidy on on‐farm agrobiodiversity and an ex post payment‐by‐result for the actual provision of public environmental benefits. In the absence of regulation, welfare may increase rather than decrease with increasing environmental risk, if the agroecosystem is characterized by a high natural insurance function, low costs, and large external benefits of agrobiodiversity.     

A detailed greenhouse gas budget for palm oil production

We have evaluated the global warming impact of palm oil production in a model that simulates the operations of a typical palm oil mill that processes fruit from a nucleus estate and outgrowers. It estimates carbon sequestration in the crop and in mill products and by-products, and balances this against the major sources of greenhouse gases (GHGs), all converted to carbon dioxide equivalents (CO₂-e) over the 25-year lifespan of the crop. The model shows that most carbon sequestration occurs in the standing crop, with smaller amounts in mill products and by-products. Land-use conversion plays a dominant role in the GHG budget, with planting of oil palm after logged forest or rubber leading to a net loss of carbon, and to a net gain following grassland. In the default oil-palm-to-oil-palm case the carbon lost from cleared palms is balanced by sequestration in the current crop. Methane from mill effluent and nitrous oxide from N fertilizers are the next most important emission sources. The default replant case gives net emissions of 0.86t CO₂-e per t crude palm oil, but these can be reduced to very low values, mainly through conversion of methane and surplus fuel in the mill to energy.     

Agriculture,trade openness and emissions: an empirical analysis and policy options

This article investigates the impact of sectoral production allocation, energy usage patterns and trade openness on pollutant emissions in a panel consisting of high‐, medium‐ and low‐income countries. Extended STIRPAT (Stochastic Impact by Regression on Population, Affluence and Technology) and EKC (Environmental Kuznets Curve) models are conducted to systematically identify these factors driving CO2 emissions in these countries during the period 1980–2010. To this end, the study employs three different heterogeneous, dynamic mean group‐type linear panel models and one nonlinear panel data estimation procedure that allows for cross‐sectional dependence. While affluence, nonrenewable energy consumption and energy intensity variables are found to drive pollutant emissions in linear models, population is also found to be a significant driver in the nonlinear model. Both service sector and agricultural value‐added levels play a significant role in reducing pollution levels, whereas industrialisation increases pollution levels. Although the linear model fails to track any significant impact of trade openness, the nonlinear model finds trade liberalisation to significantly affect emission reduction levels. All of these results suggest that economic development, and especially industrialisation strategies and environmental policies, need to be coordinated to play a greater role in emission reduction due to trade liberalisation.