Carbon Constraints Research Articles

Macroeconomic Effects of CO 2 Emission Limits: A Computable General Equilibrium Analysis for China

The study analyzes the macroeconomic effects of limiting China's CO 2 emissions by using a time-recursive dynamic computable general equilibrium (CGE) model of the Chinese economy. The baseline scenario for the Chinese economy over the period to 2010 is first developed under a set of assumptions about the exogenous variables. Next, we analyze the macroeconomic implications of two less restrictive scenarios under which China's CO 2 emissions in 2010 will be cut by 20% and 30%, respectively, relative to the baseline, assuming that carbon tax revenues are retained by the government. Then, we compute the efficiency improvement of four indirect tax offset scenarios relative to the two tax retention scenarios above. Furthermore, a comparison with other studies for China, which include the well-known global studies based on GLOBAL 2100 and GREEN, is made in terms of both the baseline scenarios and carbon constraint ones. The study ends with some concluding remarks.

95/06582 Precautionary investment behaviour in the face of a carbon constraint: The role of the credibility of the policy debate

Efforts to improve the ease of self-assembly formation through non-covalent interaction has led to the development of zinc phthalocyanine (zinc-2,9,16,23-tetra-tert-butyl phthalocyanine, i.e., ZnPc) as a high potential photosensitizer molecule towards C60 pyrrolidine tris-acid ethyl ester (PyC60) in toluene and 1,2-dichlorobenzene (DCB). Steady state fluorescence experiment elicits efficient quenching of the fluorescence intensity of both H2- and ZnPc in presence of PyC60. The average value of binding constant for PyC60/H2–Pc and PyC60/ZnPc systems in toluene (DCB) are determined to be 9910 (13,460) and 12,710 (24,060) dm3 mol−1, respectively. Lifetime experiment yields ∼3 times larger magnitude of charge separated rate constant for the PyC60/ZnPc system compared to PyC60/H2–Pc in toluene. Photoinduced energy transfer between PyC60 and H2- (/ZnPc) has been evidenced with nanosecond laser photolysis method; transient absorption studies establish that energy transfer from TPyC60∗ to H2- and ZnPc occurs predominantly, as confirmed by the consecutive appearance of the triplet states of PyC60.

Buying Greenhouse Insurance: The Economic Costs of CO 2 Emission Limits.

In recent years a growing concern that the increasing accumulation of gases will lead to undesirable changes in global climate has resulted in a number of proposals, both in the United States and internationally, to set physical targets for reducing gas emissions. But what will these proposals cost? Based on the authors' earlier ground-breaking work, Buying Greenhouse Insurance outlines a way to think about greenhouse-effect decisions under uncertainty. It describes an insightful model for determining the economic costs of limiting carbon dioxide emissions produced by burning fossil fuels and provides a solid analytical base for rethinking public policy on the farreaching issue of global warming. Manne and Richels present region-by-region estimates of the costs that would underlie an international agreement. Using a computer model known as Global 2100, they analyze the economic impacts of limiting C02 emissions under alternative supply and conservation scenarios. The results clearly indicate that a reduction in emissions is not the sole policy response to potential climate change. Following a summary of the effect, its likely causes, and possible consequences, Manne and Richels take up issues that concern the public at large. They provide an overview of Global 2100, look at how the U.S. energy sector is likely to evolve under business-as-usual conditions and under carbon constraints, and describe the concept of greenhouse insurance. They consider possible global agreements, including an estimate of benefits that might result from trading in an international market in emission rights. They conclude with a technical description directed toward modeling specialists.

Buying Greenhouse Insurance: The Economic Costs of Carbon Dioxide Emission Limits.

In recent years a growing concern that the increasing accumulation of gases will lead to undesirable changes in global climate has resulted in a number of proposals, both in the United States and internationally, to set physical targets for reducing gas emissions. But what will these proposals cost? Based on the authors' earlier ground-breaking work, Buying Greenhouse Insurance outlines a way to think about greenhouse-effect decisions under uncertainty. It describes an insightful model for determining the economic costs of limiting carbon dioxide emissions produced by burning fossil fuels and provides a solid analytical base for rethinking public policy on the farreaching issue of global warming.Manne and Richels present region-by-region estimates of the costs that would underlie an international agreement. Using a computer model known as Global 2100, they analyze the economic impacts of limiting C02 emissions under alternative supply and conservation scenarios. The results clearly indicate that a reduction in emissions is not the sole policy response to potential climate change.Following a summary of the effect, its likely causes, and possible consequences, Manne and Richels take up issues that concern the public at large. They provide an overview of Global 2100, look at how the U.S. energy sector is likely to evolve under businessas-usual conditions and under carbon constraints, and describe the concept of greenhouse insurance. They consider possible global agreements, including an estimate of benefits that might result from trading in an international market in emission rights. They conclude with a technical description directed toward modeling specialists.Alan Manne is Professor of Operations Research at Stanford University. Richard Richels is Director of the Energy Analysis and Planning Department at the Electric Power Research Institute.

Photosynthetic carbon assimilation in aquatic macrophytes

In submerged aquatic macrophytes the relationship between net photosynthesis and carbon concentration in the water often follows a less gradual pattern than anticipated assuming simple Michaelis-Menten kinetics. This indicates that other factors than the activity of the carboxylation enzymes are important in the regulation of photosynthesis in these plants. At low external concentrations of inorganic carbon, photosynthesis is restricted by the slow rate of diffusion from the bulk medium to the site of carboxylation, whereas the maximum photosynthetic capacity appears to be set by the enzyme activity or the turnover of intermediates in the carbon reduction cycle, including adenosine triphosphate (ATP) and reducing agents. The potential for active transport of inorganic carbon across the plasmalemma may also be of importance in some instances. Different strategies, which could be seen as adaptations to ameliorate the carbon constraints, have evolved in submerged macrophytes. These could be separated into physiological and exploitation strategies. Among the former, the most widespread is use of HCO 3 − in photosynthesis. The rationale for this strategy is the rather high concentration of HCO 3 − in most freshwaters and in seawater. Bicarbonate use has been found in approximately 50% of the species tested. Other physiological adaptations involve use of C 4 acids in photosynthesis based on some kind of C 4 or crassulacean acid metabolism (CAM). These strategies, however, appear to be of only minor importance, C 4-like photosynthesis is found in a few freshwater and marine species and CAM is found mainly among the isoetids and in a few other species. The exploitation strategies all involve morphological features which allow the plants to avoid or reduce carbon limitation by exploiting alternative carbon sources in addition to those in the water. The most widespread is the development of floating or aerial leaves, which allow access to the atmospheric CO 2 pool, where CO 2 is more readily available owing to the higher diffusion rate and current velocity in air relative to water. Use of sediment-CO 2, another exploitation strategy, has been recognized in several species, especially from the isoetid group. These species all have an extensive lacunal system with longitudinal channels from the roots to the leaves, providing an efficient transport route for sediment-CO 2. In these species, sediment-derived CO 2 can be responsible for more than 90% of the total carbon uptake. Sediment-CO 2 concentrations are nearly always higher than the concentration in the water column; nevertheless, significant use of sediment-CO 2 is not found in elodeid species. It has been suggested that this is due to the long diffusion path, low shoot/root ratio and a high, inherent rate of photosynthesis in these species. The carbon extraction capacity, which reflects the extent to which the plants use HCO 3 − or C 4 acids in photosynthesis, is not a constant attribute among submerged macrophytes. However, some general trends are present. The extraction capacity is high most macroalgae, intermediate in elodeid freshwater species and low in isoetids and in elodeid species with the potential of exploiting CO 2 sources other than those in water. Accordingly, light-saturated photosynthesis in marine macroalgae is often carbon saturated at natural inorganic carbon concentrations, but rarely so among freshwater macrophytes. In addition to these apparently genetic differences in carbon extraction capacity among the plant groups, environmental conditions also influence the carbon uptake characteristics. When carbon is not limiting, i.e. at high CO 2 and low light, high extraction capacity and carbon affinity are suppressed. This response seems appropriate as the plants thereby reduce investment in carbon acquisition systems when not needed and instead allocate energy to increase assimilation of more limiting resources. Thus, it is apparent that submerged macrophytes possess a homeostatic capacity that reduces the effects of imbalance among resources needed. However, it is evident that aquatic macrophytes, in particular freshwater species, often have an excess capacity for carbon assimilation not realized at ambient conditions of inorganic carbon. The significance of this overcapacity is unclear, but it stresses the importance of inorganic carbon as a potential limiting factor for photosynthesis and possibly growth of submerged aquatic macrophytes.

C02 Emission Limits: An Economic Cost Analysis for the USA

This paper provides a cost-benefit analysis of controlling or decreasing CO2 emissions. It uses an analytical framework, called Global 2100, which is designed to evaluated C02 energy economy interactions and estimate the cost of a carbon emissions limit. It analyzes three demand parameters (potential GNP growth, elasticity of price induced substitution between capital-labour and energy, and the rate of autonomous energy efficiency improvements) which are crucial to the debate over energy and environmental futures. The paper discusses various energy sources which are either presently in use or will possibly be in use in the future, and analyzes their impact on cost-benefit analyses. Finally, the paper analyzes the results of carbon constraints and suggests that there is need for more research and development on the subject.

Carbon and helium isotopic constraints on the origin of volcanic carbon from subduction zones

Carbon and helium isotopic constraints on the origin of volcanic carbon from subduction zones