Daiju Narita

Economic costs of ocean acidification: a look into the impacts on global shellfish production

Ocean acidification is increasingly recognized as a major global problem. Yet economic assessments of its effects are currently almost absent. Unlike most other marine organisms, mollusks, which have significant commercial value worldwide, have relatively solid scientific evidence of biological impact of acidification and allow us to make such an economic evaluation. By performing a partial-equilibrium analysis, we estimate global and regional economic costs of production loss of mollusks due to ocean acidification. Our results show that the costs for the world as a whole could be over 100 billion USD with an assumption of increasing demand of mollusks with expected income growths combined with a business-as-usual emission trend towards the year 2100. The major determinants of cost levels are the impacts on the Chinese production, which is dominant in the world, and the expected demand increase of mollusks in today’s developing countries, which include China, in accordance with their future income rise. Our results have direct implications for climate policy. Because the ocean acidifies faster than the atmosphere warms, the acidification effects on mollusks would raise the social cost of carbon more strongly than the estimated damage adds to the damage costs of climate change.

Uncertainty in Integrated Assessment Models of Climate Change: Alternative Analytical Approaches

Uncertainty plays a key role in the economics of climate change, and the discussions surrounding its implications for climate policy are far from settled. We give an overview of the literature on uncertainty in integrated assessment models of climate change and identify some future research needs. In the paper, we pay particular attention to three different and complementary approaches that model uncertainty in association with integrated assessment models: the discrete uncertainty modeling, the most common way to incorporate uncertainty in complex climate-economy models: the real options analysis, a simplified way to identify and value flexibility: the continuous-time stochastic dynamic programming, which is computationally most challenging but necessary if persistent stochasticity is considered.

Economic costs of extratropical storms under climate change: an application of FUND

Extratropical cyclones have attracted some attention in climate policy circles as a possible significant damage factor of climate change. This study conducts an assessment of economic impacts of increased storm activities under climate change with the integrated assessment model FUND 3.5. In the base case, the direct economic damage of enhanced storms due to climate change amounts to US

Environmental tipping points significantly affect the cost−benefit assessment of climate policies

2.8 billion globally (approximately 38% of the total economic loss of storms at present) at the year 2100, while its ratio to the world GDP is 0.0009%. The paper also shows various sensitivity runs exhibiting up to 3 times the level of damage relative to the base run.

Risk‐Averse Mitigation Decisions in an Unpredictable Climate System

Significance Most current cost−benefit analyses of climate change suggest global climate policy should be relatively weak. However, relatively few studies account for the market or nonmarket impacts of passing environmental tipping points that cause abrupt and irreversible damages. We use a stochastic dynamic model of the climate and economy to quantify the effect of tipping points on climate change policy. We show that environmental tipping points can profoundly alter cost−benefit analysis, justifying a much more stringent climate policy, which takes the form of a higher immediate price on carbon. Most current cost−benefit analyses of climate change policies suggest an optimal global climate policy that is significantly less stringent than the level required to meet the internationally agreed 2 °C target. This is partly because the sum of estimated economic damage of climate change across various sectors, such as energy use and changes in agricultural production, results in only a small economic loss or even a small economic gain in the gross world product under predicted levels of climate change. However, those cost−benefit analyses rarely take account of environmental tipping points leading to abrupt and irreversible impacts on market and nonmarket goods and services, including those provided by the climate and by ecosystems. Here we show that including environmental tipping point impacts in a stochastic dynamic integrated assessment model profoundly alters cost−benefit assessment of global climate policy. The risk of a tipping point, even if it only has nonmarket impacts, could substantially increase the present optimal carbon tax. For example, a risk of only 5% loss in nonmarket goods that occurs with a 5% annual probability at 4 °C increase of the global surface temperature causes an immediate two-thirds increase in optimal carbon tax. If the tipping point also has a 5% impact on market goods, the optimal carbon tax increases by more than a factor of 3. Hence existing cost−benefit assessments of global climate policy may be significantly underestimating the needs for controlling climate change.

The economic impacts of ocean acidification

Risk aversion plays a central role in the decisions made in the face of uncertainties, and climate-change mitigation should be no exception. However, the interlinkage of risk aversion and climate-change uncertainties has hardly been investigated numerically, in part because of the computational difficulties of stochastic optimization. In this paper, we apply the numerical techniques of stochastic optimization to the economic modeling of climate change, with the aim of modeling the decision preferences of a risk-conscious agent in the face of unpredictable climate change. The model underlines the critical role played by the risk-aversion parameter in determining the effects of uncertainties on mitigation, not only in level but also in sign.

Economic Optimality of CCS Use: A Resource-Economic Model

Ocean acidification caused by the increased uptake of atmospheric carbon dioxide by the oceans is likely to have serious impacts on marine organisms that make shells and exoskeletons from calcium carbonate. The consequences for the provision of marine ecosystem services such as fisheries and services generated by coral reefs are uncertain but potentially severe. In this chapter we set out a framework for the economic assessment of impacts from ocean acidification. We review the existing economic literature on ocean acidification, which is nascent and sparse. To date only a partial set of the potentially impacted ecosystem services have been assessed with a focus on the direct use values that can be more easily addressed. Gaps in the current knowledge are identified and avenues for future research are discussed. Comparing the existing impact estimates for ocean acidification with those for climate change show them to be an order of magnitude lower. Due to the relatively proximate impacts of ocean acidification, however, the implications for optimal mitigation of carbon dioxide emissions may be substantial.

Embedding CCS infrastructure into the European electricity system: A policy coordination problem

CCS (carbon dioxide capture and storage) is an issue which has received increasing attention in the debate on climate change over the last several years because of its relative technical simplicity and very large potential in reducing carbon dioxide emissions. The absence of secondary benefits and uncertainties associated with this approach, however, would require analysts to conduct fine cost-benefit comparisons vis-a-vis other mitigation options. The paper is to provide a perspective on future cost-benefit discussions of CCS by highlighting the optimality of CCS use viewed as a non-renewable resource with a limited capacity. Scarcity of CCS (storage) capacity should involve a shadow price which could raise CCS’s effective price – this is a fair assumption given the technological assessments of CCS so far, but no economic study has explicitly investigated this characteristic before. By using a simple analytical dynamic optimization model, we examine the optimal paths of CCS use, CCS’s real price inclusive of the shadow price, and their difference from the operational price. A particular implication of the model is that if all else is equal, the shadow price of CCS could make the technology relatively less attractive than renewable energy due to CCS’s reliance on scarce reservoirs and the resultant shadow value. This serves as a justification for giving differentiated incentives to different CO2 reduction options: more precisely, more encouragement should be given to renewable energy in comparison to CCS.

Economic impact of ocean acidification on shellfish production in Europe

Carbon dioxide capture and storage (CCS) has recently been receiving increasing recognition in policy debates. Various aspects of possible regulatory frameworks for its implementation are beginning to be discussed in Europe. One of the issues associated with the wide use of CCS is that it requires the establishment of a carbon dioxide (CO2) transport network, which could result in the spatial restructuring of power generation and transmission systems. This poses a significant coordination problem necessitating public planning and regulation. This paper provides a survey over multiple research strands on CCS, particularly energy system modeling and spatial optimization, pertaining to the efficient installment of CCS-related infrastructure throughout Europe. It integrates existing findings and highlights the factors that determine policy coordination needs for a potential wide implementation of CCS in the next decades.

The household production function approach to valuing climate: the case of Japan

Ocean acidification (OA) is increasingly recognized as a major global problem. Despite the scientific evidence, economic assessments of its effects are few. This analysis is an attempt to perform a national and sub-national assessment of the economic impact of OA on mollusc production in Europe. We focus on mollusc production because the scientific evidence on the biological impact on calcifying organisms is ample relative to other types of marine organisms. In addition, Europe and its regions are significant producers of marine molluscs. By performing a partial-equilibrium analysis, we show that the highest levels of overall impact are found in the countries with the largest current production, such as France, Italy and Spain. For Europe as a whole, the annual impact will be over 1 billion USD in 2100. Due to the different production foci of the individual countries and their regions, the distribution of the impact is extremely uneven across countries and their respective regions, with the most affected sub-national regions being those on the Atlantic coast of France, which is an important region for oyster production.