Under the Kyoto Protocol, reductions in emissions of several radiative gases can be credited against a carbon equivalent emissions cap. We investigate the economic implications of including other greenhouse gases and sinks in the climate change control policy using our revised and updated version of the Emissions Prediction and Policy Analysis (EPPA) model. In addition we amended our methane abatement curves based on different interpretations of estimates that substantial abatement of methane can be obtained at no cost. The inclusion of other greenhouse gases and CO2 sinks reduces the costs of achieving CO2 emissions reductions specified under the agreement. / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change Website. (http://mit.edu/globalchange/www/) / Includes bibliographical references (p. 7).

EPA's legal authority to regulate greenhouse gas emissions under the Clean Air Act is reviewed. While EPA clearly does not have the authority to implement the precise terms of the Kyoto Protocol, arguments could be put forward to support the Agency's claim that it has the authority to control such pollutants. However, the Clean Air Act's legislative history, a textual analysis of the Act, judicial precedents and political considerations all provide compelling arguments for the EPA to seek additional legislation before attempting to regulate greenhouse gases. Even a generous interpretation of existing provisions would prohibit trading in greenhouse gas emissions permits and therefore contradicts the Administration's own preferred approach to addressing climate change which favors employing market mechanisms to help reduce the costs of carrying out reductions. Moreover, the participation of developing countries in an emissions control regime, which has been stipulated by the Senate and endorsed by the Administration, would also remain unaffected since the Clean Air Act is only designed to address local and regional pollution. Concerns over backdoor implementation of the Kyoto Protocol and EPA's attempts to regulate emissions help explain the political attacks on the agency's efforts to pursue research, education, and non-regulatory solutions to the climate change problem. / Includes bibliographical references. / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)

Under the Kyoto Protocol, the world's wealthier countries assumed binding commitments to reduce greenhouse gas emissions. The agreement requires these countries to consider ways to minimize adverse effects on developing countries of these actions, transmitted through trade. Using a general equilibrium model of the world economy, we find that adverse effects fall mainly on energy-exporting countries, for some even greater than on countries that are assuming commitments. Removing existing fuel taxes and subsidies and using international permit trading would greatly reduce the adverse impacts and also reduce economic impacts on the countries taking on commitments. Another approach, preferential tariff reduction for developing countries, would benefit many developing countries, but would not target those most adversely affected. If instead, OECD countries directly compensated developing countries for losses, the required annual financial transfer would be on the order of $25 billion (1995 $US) in 2010. / Includes bibliographical references (p. 19-20). / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)

Changes in runoff from Greenland and Antarctica are often cited as one of the major concerns linked to anthropogenic changes in climate. The changes in mass balance, and associated changes in sea-level, of these two ice sheets are examined by comparing the predictions of the six possible combinations of two climate models and three methods for estimating melting and runoff. All models are solved on 20 and 40 km grids respectively for Greenland and Antarctica. The two temperature based runoff parameterizations give adequate results for Greenland, less so for Antarctica. The energy balance based approach, which relies on an explicit modelling of the temperature and density structure within the snow cover, gives similar results when coupled to either climate model. The Greenland ice sheet, for a reference climate scenario similar to the IPCC's IS92a, is not expected to contribute significantly to changes in the level of the ocean over the 21st century. The changes in mass balance in Antarctica are dominated by the increase in snowfall, leading to a decrease in sea-level of 4 cm by 2100. The range of uncertainty in these predictions is estimated by repeating the calculation with the simpler climate model for seven climate change scenarios. Greenland would increase the level of the oceans by 0 - 2 cm, while Antarctica would decrease it by 2.5 - 6.5 cm. The combined effect of both ice sheets lowers the sea-level by 2.5 - 4.5 cm over the next 100 years, this represents a 25% reduction of the sea-level rise estimated from thermal expansion alone. This surprisingly small range of uncertainty is due to cancellations between the effects of the two ice sheets. For the same reason, the imposition of the Kyoto Protocol has no impact on the prediction of sea-level change due to changes in Greenland and Antarctica, when compared to a reference scenario in which emissions are allowed to grow unconstrained. / Includes bibliographical references (p. 26-28). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/) / Supported by the Alliance for Global Sustainability, the MIT Joint Program on the Science and Policy of Global Change and NASA as part of the NASA GISS Interdisciplinary EOS Investigation NAG 5-7204

The six possible combinations of two climate models and three methods for calculating the melting of snow and ice are used to estimate current values of accumulation and ablation on the Greenland and Antarctic ice sheets. This allows the contrasting of high vs. low resolution climate input and to assess the reliability of simple temperature based parameterizations of melting when compared to a physical model of the seasonal evolution of the snow cover. In contrast to past efforts at modelling the mass balance of Greenland and Antarctica, the latter model allows an explicit calculation of the formation of meltwater, of the fraction of meltwater which refreezes and of runoff in the ablation region, this is not the case for the other two melt models. While the higher resolution GCM (ECHAM 4) does bring the estimation of accumulation closer to observations, it fails to give accurate results in its predictions of runoff. The simpler climate model (MIT 2D LO) overestimates accumulation in Antarctica but produces satisfactory estimates of runoff from the Greenland ice sheet. Both models reproduce some of the characteristics of the extent of the wet snow zone observed with satellite remote sensing, but the MIT model is closer to observations in terms of areal extent and intensity of the melting. The temperature dependent melting parameterizations generally require an accuracy in the climatic input beyond what is currently achieved to produce reliable. Because it is based on physical principles and relies on the surface energy balance as input, the snow cover model is believed to have the capability to respond adequately to the current climatic forcing as well as to future changes in climate. / Includes bibliographical references (p. 31-34). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/) / Supported by the Alliance for Global Sustainability, the MIT Joint Program on the Science and Policy of Global Change and NASA as part of the NASA GISS Interdisciplinary EOS Investigation NAG5-7204

Economic links among countries, through trade, will cause the effects of greenhouse-gas control measures taken by one set of nations to ripple through the international trade system, affecting countries that may not have agreed to share the burdens of control. So, for example, emission restrictions under the Kyoto Protocol will increase the cost to Annex B regions of using carbon-emitting fuels and raise the manufacturing cost of their energy-intensive goods, which may be exported in part to developing countries. The restrictions also will lower the global demand for these fuels and reduce their international prices. In addition, the emissions controls may depress the level of economic activity in countries under emissions restriction, lowering their demand for imports, some of which come from developing countries. In combination, these changes in trade volumes and prices can have complex consequences, harming some developing countries while benefiting others. This paper explores these consequences using a detailed Computable General Equilibrium (CGE) model of the world economy. / Includes bibliographical references (p. 26-28). / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/) / Supported in part by the U.S. Dept. of Energy 901214-HAR DE-FG02-94ER61937 DE-FG0293ER61713 Supported in part by the U.S. Environmental Protection Agency CR-820662002 Also supported by the Royal Norwegian Ministries of Energy and Industry and Foreign Affairs.

Continually increasing atmospheric concentrations of radiatively important chemical species such as CO2, CH4, N2O, tropospheric O3, and certain halocarbons most likely will cause future climate changes, which could in turn impact chemical reaction rates and thus lifetimes of many important chemical species. Complicated interactions between climate dynamics and atmospheric chemistry strongly suggest that a fully interactive, comprehensive chemistry-climate modeling system is needed to study the issue. This article reviews recent work in the new and challenging field of interactive chemistry-climate modeling, describing major efforts in model development and summarizing in detail applications of and results from these models. / Includes bibliographical references (p. 12-16). / Abstract in HTML and technical report in PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)

We find that, on an economic basis, nuclear power could make a substantial contribution for meeting the emissions target Japan agreed to in the Kyoto Protocol. It is unlikely however that the contribution would be as large as projected in official Japanese forecasts. The economic costs of the carbon constraint rise if siting, construction, and approval problems prevent the economically desirable level of expansion of nuclear power. We also evaluate the economic effects of subsidizing nuclear power to achieve the expansion projected in official forecasts. While the subsidy required is substantial, the economic welfare effects are relatively small because of second-best considerations. We use the EPPA model, a global computable general equilibrium model, in the analysis. Our estimates thus include the effects of changing world energy prices and terms of trade as they affect competitiveness of nuclear power and economic welfare. / Includes bibliographical references (p. 12). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)

This paper presents an investigation of the relations in China between farm output, the natural fertility of agricultural land, and the use of anthropogenic farm inputs. The methodology is presented as a potential increment to the analysis of the effects of climate change in agriculture. Variations of climate, soil and topographic conditions, and direct farm inputs across the prefectures of China are used to determine their effects on the output of particular crops. The study estimates crop production functions with conventional land, labor, fertilizer and mechanical inputs, and the net primary productivity (NPP) projections of the Terrestrial Ecosystems Model to reflect climatic conditions. Estimates of the NPP of the land in each prefecture are used to simulate the effects of climate and other natural growing conditions. The results suggest that there is substantial scope for increasing food production in China by increasing its irrigation of farm land and the use of farm inputs of fertilizer and mechanical power. / Includes bibliographical references (p. 15). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)

Years of hard bargaining have failed to produce a policy architecture to adequately address the complexities of climate change. Very likely, such a structure will have to be sought though improvement of the partial architecture developed to date within the Framework Convention on Climate Change. We identify key architectural features that have emerged in the Convention process, and then explore extensions that will be necessary if the current approach is to serve for the long term. An important task is to break the deadlock over accession of developing countries. To this end we propose further incorporation in the negotiations of concepts of burden sharing according to ability to pay that already seem to be embedded in the Convention. The implications of alternative versions of such an approach are illustrated with a set of simple model simulations. / Includes bibliographical references (p. 23-24). / Abstract in HTML and technical report in HTML and PDF available on the Massachusetts Institute of Technology Joint Program on the Science and Policy of Global Change website (http://mit.edu/globalchange/www/)