The impact of uncertainty in the rate of heat and carbon uptake by the deep ocean on climate response to increases in greenhouse gas concentrations is studied by means of numerical simulations with the two-dimensional climate-chemistry model developed in the framework of the MIT Global Change Joint Program. This model incorporates parameterizations of most physical processes, includes fully interactive atmospheric chemistry and calculates carbon uptake by the ocean and, therefore, simulates the main nonlinear interactions taking place in the climate system. At the same time, it is much more computationally efficient than coupled atmosphere-ocean general circulation models. Results of the simulations with calculated CO2 concentrations are compared with those of simulations with a prescribed CO2 increase. This comparison shows that the uncertainty in the increase in global mean surface temperature due to uncertainty in the rate of oceanic heat uptake is enhanced by taking into account the related uncertainty in oceanic carbon uptake, while the uncertainty in sea level rise is decreased. / Includes bibliographical references (p. 5). / 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 provides a comparative analysis of the economic and political interests influencing the progress of climate negotiation. The primary focus is on the U.S., France, Germany, U.K., Belgium, Netherlands, and the E.U. itself. A discussion of the drivers of policy and differing responses on a national basis is presented to highlight the larger influences at work. The driving factors range across economic and political interests, public concern, bureaucratic goals, scientific evidence, non-governmental organizations, energy industries, and are relevant in each country to varying degrees. Also included is a personal forecast of what can be expected to emerge in the next few months as the current negotiations reach their climax in Kyoto, Japan, in December 1997. / Includes bibliographical references. / 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/)

Through a brief look at the science and economics of climate, the authors show that if climate change turns out to be a serious threat, an effective response will require a substantial and very long-term global effort. Today's focus on near-term emissions reductions will be counter-productive if it delays development of the institutions and policy architectures that would be necessary to mount and sustain such an effort over much of the next century. The authors discuss three legacies that our generation could leave that would make this struggle to devise a global response easier: (1) an international climate agreement that could, if necessary, reduce greenhouse gas emissions substantially, at least cost, while being responsive both to changes in our scientific understanding and to evolving political and economic conditions, (2) enhanced technical options that could, if necessary, ease the task of maintaining economic growth while controlling greenhouse gas emissions, and (3) an international system that could, if necessary, transfer substantial sums to developing countries to assist their participation in an emissions control effort. Building these legacies is a huge challenge, but this task merits at least the same sense of urgency that has motivated pre-Kyoto negotiations about short-term CO2 emissions reductions. / 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/).

We have derived a parameterization consisting of a set of analytical expressions that approximate the predictions by the CIT Urban Airshed Model for the net export to the environment (i.e., effective emissions) of several chemical species, as functions of fourteen input parameters. For each species, effective emissions are a function of actual urban emissions of this and other species and of other urban domain properties such as meteorology. Effective emissions may be "aged" emissions of primary pollutants or actual production of secondary pollutants. To develop the parameterization we have applied the probabilistic collocation method, which uses the probability density functions of the inputs to generate a set of orthogonal polynomials. These polynomials are then used as the basis for a polynomial chaos expansion that approximates the actual response of the CIT model to its inputs. We assume that seasonal variations can be represented by sinusoidal functions. The parameterization provides a computationally very efficient simulation of the actual model behavior. We have compared the outputs of the parameterization with the outputs of the CIT model, and we conclude that it gives a quite good approximation for effective emissions, at least in the regions of highest probability of the input parameters. This parameterization is applicable to detailed uncertainty and sensitivity analyses and enables computationally efficient inclusion of urban-scale processes as sub-grid scale phenomena in global-scale models. / Includes bibliographical references (p. 29-30). / 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/). / Funded by the Comissió Interdepartmental de Recerca i Innovació Tecnològica (CIRIT), Catalunya, Spain and supported by the U.S. National Science Foundation. 95-23616.

This paper is based on a Master of Science thesis submitted to the MIT Technology and Policy Program in May, 1997, and also appeared as Working Paper 97-003 in the MIT Center for Energy and Environmental Policy Research (CEEPR) series. / Includes bibliographical references (p. 29-31). / 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 in part by a grant from Tokyo Electric Power Company to the Joint Program on the Science and Policy of Global Change, and in part by the U.S. Environmental Protection Agency through Cooperative Agreement. no. CR820662-01-0

A cropland distribution model, which is based on climate, soil and topography, is applied to estimate the area and spatial distribution of global potential croplands under contemporary climate and to assess the effect of transient climate changes projected by the MIT Integrated Global System Model for assessment of climate change. The area of global potential croplands is about 32.91 x 10^6 km^2 under contemporary climate, and increases substantially over the period of 1977-2100 and differs among the three transient climate change predictions, being about +6.7% (2.20 x 10^6 km^2), +11.5% (3.78 x 10^6 km^2), and +12.5% (4.12 x 10^6 km^2) in 2100, respectively. Among twelve economic regions of the world, the Former Soviet Union and the Other OECD Countries regions have the largest increases in potential croplands, while developing countries have little increases in potential croplands. Spatial distribution of potential croplands changes considerably over time, dependent upon the transient climate change predictions. / Includes bibliographical references (p. 9-12). / 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/). / Supported by the Joint Program on the Science and Policy of Global Change at the Massachusetts Institute of Technology (CE-S-462041), and the National Institute of Global Environmental Changes of the Department of Energy. No:901214-HAR Supported by the Earth Observing Systems Program of NASA. NAGW-2669

Includes bibliographical references (p. 14-15). / 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/).

This paper analyzes the determinants of deforestation in the Brazilian Amazon. From a model of optimal land use, it derives and then estimates a deforestation equation on country-level data for the period 1978 to 1988. The data include a deforestation measure from satellite images, which is a great advance in that it allows improved within-country analysis. Evidence exists that: increased road density in a country leads to more deforestation in that country and in neighboring countries; government-subsidized development projects increase deforestation; greater distance from markets south of the Amazon leads to less deforestation; and better soil quality leads to more deforestation. The results for government provision of credit are mixed across specifications. The population density, although the primary explanatory variable in most previous empirical work, does not have a significant effect when all the variables motivated within the model are included. However, a quadratic specification yields a more robust population result: the first few people entering an empty country have significantly more impact than the same number of people added to a densely populated country. This result suggests the importance of the spatial distribution of population. / 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/). / Includes bibliographical references.

A multi-sector multi-region general equilibrium model of economic growth and emissions is used to explore the conditions that will determine the market penetration of CO2 capture and disposal technology. / Includes bibliographical references (p. 16). / 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/). / Support through a government-industry partnership including the U.S. Dept. of Energy. 901214-HAR, DE-F02-94ER61937, DE-F02-94ER61713 Support from U.S. Environmental Protection Agency. CR-820662-02 Support from a group of corporate sponsors from the United States, Europe and Japan, and the Electric Power Research Institute. W02141-23

The MIT Emissions Prediction and Policy Analysis (EPPA) model is applied to an exploration of the national emissions obligations that would be required to stabilize atmospheric CO2 concentrations at levels now under active discussion. The results indicate that the needed voluntary participation will be difficult to achieve, not least because nations at very different income levels would have to undertake similarly costly emissions restrictions. The need for more attention to the linkage between short-term policy proposals and long-term stabilization goals is highlighted. / Includes bibliographical references (p. 16). / 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/).