Regional Analysis

Power Ahead: Meeting Ethiopia's Energy Needs Under a Changing Climate

Ethiopia is powering ahead with an energy development strategy that is highly reliant on abundant hydropower potential. A changing climate may pose a challenge to meeting expected targets. Bridging the modeling gaps between climate, energy, and economics, and effectively transforming climate changes into economic measures, is an emerging interdisciplinary field as nations attempt to position themselves for an uncertain future. Such a framework is adopted here to assess energy production and adaptation costs for four climate change scenarios over 2010–2049. Scenarios that favor a drying trend countrywide may lead to losses of 130–200 terawatt-hours over the 40-year period, translating to adaptation costs of US$2–4 billion, compared with a no climate change scenario. Even given these potential losses, energy development utilizing hydropower appears economically reasonable from this deterministic, sector-independent evaluation. This development is desperately needed, independent of future climate change trends, with the hope of appreciably reducing vulnerability to variability.

Probabilistic forecast for climate change over Northern Eurasia

In this study, we investigate possible climate change over Northern Eurasia and its impact on hydrological and carbon cycles. Northern Eurasia is a major player in the global carbon budget because of boreal forests and wetlands. Permafrost degradation associated with climate change could result in wetlands releasing large amounts of carbon dioxide and methane. Changes in the frequency and magnitude of extreme events, such as extreme precipitation, are likely to have substantial impacts on Northern Eurasia ecosystems. For this reason, it is very important to quantify the possible climate change over Northern Eurasia under different emissions scenarios, while accounting for the uncertainty in the climate response.

Probabilistic Projections of 21st Century Climate Change over Northern Eurasia

We present probabilistic projections of 21st century climate change over Northern Eurasia using the Massachusetts Institute of Technology (MIT) Integrated Global System Model (IGSM), an integrated assessment model that couples an earth system model of intermediate complexity with a two-dimensional zonal-mean atmosphere, to a human activity model. Regional climate change is obtained by two downscaling methods: a dynamical downscaling, where the IGSM is linked to a three-dimensional atmospheric model; and a statistical downscaling, where a pattern scaling algorithm uses climate-change patterns from 17 climate models. This framework allows for key sources of uncertainty in future projections of regional climate change to be accounted for: emissions projections; climate system parameters (climate sensitivity, strength of aerosol forcing and ocean heat uptake rate); natural variability; and structural uncertainty. Results show that the choice of climate policy and the climate parameters are the largest drivers of uncertainty. We also find that different initial conditions lead to differences in patterns of change as large as when using different climate models. Finally, this analysis reveals the wide range of possible climate change over Northern Eurasia, emphasizing the need to consider all sources of uncertainty when modeling climate impacts over Northern Eurasia.

Quantifying Emissions of Greenhouse Gases from South Asia Through a Targeted Measurement Campaign

Methane (CH4), nitrous oxide (N2O) and sulfur hexafluoride (SF6) are powerful greenhouse gases with global budgets that are well-known but regional distributions that are not adequately constrained for the purposes of mitigation and policy initiatives. Quantifying emissions using inverse approaches at the national scale requires measurements that specifically target the region of interest. Primarily due to the lack of atmospheric measurements from the region, emissions estimates of these greenhouse gases from India have largely been missing.

New in situ measurements of atmospheric mole fractions from a Himalayan station in Darjeeling, India (27.03N, 88.26E, 2200 meters above sea level) have been collected from December 2011 for CH4 and March 2012 for N2O and SF6 to February 2013 using high-precision instrumentation that is linked to the Advanced Global Atmospheric Gases Experiment (AGAGE). These measurements comprise the rest high-frequency dataset of these gases collected in India and are used for measurement-based assessment of emissions. Several features are identified. In SF6, the signal associated with Northern Hemispheric background is typically present. CH4 and N2O mole fractions are almost always enhanced over the background, suggesting strong regional sources. Additionally, a diurnal signal resulting from thermally driven winds is seasonally present.

A particle dispersion model is used to track `air histories' of measurements, quantifying the sensitivity of concentrations at Darjeeling to surface emissions. The effect of topography on the derived air histories is investigated to test the robustness of the model in simulating transport in this complex environment. The newly acquired data set is used to investigate the ability of the model to reproduce signals that stem from the mesoscale diurnal winds. The sensitivities of meteorological resolution and particle release height are investigated to better quantify some of the uncertainties associated with this chemical transport model.

A Quasi-Newton inverse method is used to estimate emissions at monthly resolution. CH4, N2O and SF6 emissions from India are found to be 44.354:2 38:5 Tg yr1 , 8251045 707 GgN yr1 and 221241 205 kton yr1 , respectively. Significant uncertainty reduction is seen on emissions from India during the summer when the monsoon results in high sensitivity over the subcontinent

Quantifying Regional Economic Impacts of CO2 Intensity Targets in China

To address rising energy use and CO2 emissions, China’s leadership has enacted energy and CO2 intensity targets under the Twelfth Five-Year Plan (2011–2015), which are defined at both the national and provincial levels. We develop a computable general equilibrium (CGE) model with global coverage that disaggregates China’s 30 provinces and includes energy system detail, and apply it to assess the impact of provincial CO2 emissions intensity targets. We compare the impact of the provincial targets approach to a single national target for China that achieves the same reduction in CO2 emissions intensity at the national level. We find that at the national level, the national target results in 25% lower welfare loss relative to the provincial targets approach. Given that the regional distribution of impacts has been an important consideration in the target-setting process, we focus on the changes in provincial level CO2 emissions intensity, CO2 emissions, energy consumption, and economic welfare. We observe significant heterogeneity across provinces in terms of the energy system response as well as the magnitude and sometimes sign of welfare impacts. We further model the current policy of fixed end-use electricity prices in China and find that national welfare losses increase. Assumptions about capital mobility have a substantial impact on national welfare loss, while assumptions about natural gas resource potential does not have a large effect.

Regulatory and Technical Barriers to Wind Energy Integration in Northeast China

China leads the world in installed wind capacity, which forms an integral part of its long-term goals to reduce the environmental impacts of the electricity sector. This primarily centrally-managed wind policy has concentrated wind development in a handful of regions, challenging regulatory frameworks and grid architectures to cost-effectively integrate wind. In 2013, according to official statistics, wind accounted for 2.7% of national generation, while the rate of curtailment (available wind not accepted by the grid operator onto the system) reached 12%.

Wind integration challenges have arisen in China for technical, economic and institutional reasons. From a technology standpoint, the variability and unpredictability of wind resources interact with technical limits of conventional generators, resulting in efficiency losses and grid stability concerns. Existing coal-based electricity and district heating installations play a large role in grid integration challenges because of the inflexible operation of coal plants relative to natural gas and hydropower, and the “must-run” nature of cogeneration units supplying residential heat. A competing set of hypotheses to explain current rates of wind spillage focus on institutional imperfections in China’s power sector, such as poorly designed market incentives, inadequate oversight, and a mixture of conflicting policies that are the result of an incomplete transition to a market-driven electricity system.

A unit commitment and dispatch optimization was developed to understand the underlying technical factors leading to wind curtailment in northeastern China. It incorporates electricity output restrictions from exogenous district heating demands, a hydro-thermal coordination component considering inter-seasonal storage, and transmission between adjacent provincial nodes. Averaging over six historic wind profiles, a curtailment rate of 6.6% was observed in the reference case from various forms of inflexibility and insufficient demand. The impacts of several technology-based solutions on total cost, coal use and wind curtailment, were also examined: more flexible operation of coal units, temporary heat storage and minimum cogeneration outputs that vary with heat load.

Contributing to the existing body of qualitative work on the effects of these factors, this thesis developed a straightforward methodology to assess the relative contribution of regulatory and technical causes. Two important institutional arrangements – the decentralization of dispatch to individual provinces and minimum generation quotas allocated to all coal generators – were quantified in an optimization framework, and found to be significant contributors of power system operational inflexibility.

Rising methane emissions in response to climate change in Northern Eurasia during the 21st century

We used a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to examine the methane (CH4) exchanges between terrestrial ecosystems and the atmosphere in Northern Eurasia from 1971 to 2100. Multiple model simulations using various wetland extent datasets and climate change scenarios were conducted to assess the uncertainty of CH4 fluxes, including emissions and consumption. On the basis of these simulations we estimate the current net emissions in the region to be 20–24 Tg CH4 yr − 1 (1 Tg = 1012 g), two-thirds of which are emitted during the summer. In response to climate change over the 21st century, the annual CH4 emissions in the region are projected to increase at a rate of 0.06 Tg CH4 yr − 1, which is an order of magnitude greater than that of annual CH4 consumption. Further, the annual net CH4 emissions are projected to increase by 6–51% under various wetland extent datasets and climate scenarios by the end of the 21st century, relative to present conditions. Spatial patterns of net CH4 emissions were determined by wetland extent. Net CH4 emissions were dominated by wetlands within boreal forests, grasslands and wet tundra areas in the region. Correlation analyses indicated that water table depth and soil temperature were the two most important environmental controls on both CH4 emissions and consumption in the region. Our uncertainty analyses indicated that the uncertainty in wetland extent had a larger effect on future CH4 emissions than the uncertainty in future climate. This study suggests that better characterization of the spatial distribution and the natural diversity of wetlands should be a research priority for quantifying CH4 fluxes in this region.

Shale Gas in China: Can We Expect a "Revolution"?

Natural gas in China has a substantial potential to grow from its current small share of the total energy use. The growth will contribute to lower air pollution and carbon emissions. Shale gas resources provide an opportunity for expansion and their development reduces dependence on energy imports. We estimate the costs of shale gas supply in China and use the MIT Emissions Predictions and Policy Analysis (EPPA) model to consider the impact of shale gas development on production, consumption, and international trade in natural gas. China’s shale gas production is assessed to be more expensive in comparison to the current shale gas production in the U.S. The large shale resource might be a potential game changer in terms of energy production and consumption in China. However, even with favorable economic conditions, a substantial development of this resource might take a considerable amount of time.

Synergy between Pollution and Carbon Emissions Control: Comparing China and the U.S.

We estimate the potential synergy between pollution and climate control in the U.S. and China, summarizing the results as emissions cross-elasticities of control. We set a range of NOx and SO2 targets, and record the ancillary reduction in CO2 to calculate the percentage change in CO2 divided by the percentage change in NOx (SO2) denoted as ECO2,NOx (ECO2,SO2). Then we conduct the opposite experiment, setting targets for CO2 and recording the ancillary reduction in NOx and SO2 to compute ENOx,CO2 and ESO2,CO2. For ECO2,NOx and ECO2,SO2 we find low values (0.06"’0.23) in both countries with small (10%) reduction targets that rise to 0.40"’0.67 in the U.S. and 0.83"’1.03 in China when targets are more stringent (75% reduction). This pattern reflects the availability of pollution control to target individual pollutants for smaller reductions but the need for wholesale change toward non-fossil technologies when large reductions are required. We trace the especially high cross elasticities in China to its higher dependence on coal. These results are promising in that China may have more incentive to greatly reduce SO2 and NOx with readily apparent pollution benefits in China, that at the same time would significantly reduce CO2 emissions. The majority of existing studies have focused on the effect of CO2 abatement on other pollutants, typically finding strong cross effects. We find similar strong effects but with less dependence on the stringency of control, and stronger effects in the U.S. than in China.

Synergy between Pollution and Climate Control: Comparing China and the United States

In this study, we estimate potential synergy between pollution and climate control in the U.S. and China and conduct a cross-country comparison. When measured as cross-emissions elasticity, ancillary CO2 abatement from unit % reduction of NOx and SO2 emissions is substantially greater in China under stringent targets, though comparable between the two countries under moderate targets. In contrast, NOx and SO2 abatement from unit % reduction of CO2 emissions is much greater in the U.S. than in China, regardless of the stringency of the policy shock. These results are primarily driven by China’s higher dependence on coal, as coal has larger unit emission-reduction effects than other fossil fuels and its intensive use creates more room for less costly fuel-switching and abatement options. In addition, pollution-abatement co-benefits of carbon mitigation tend to be greater than carbon-mitigation co-benefits of NOx and SO2 reduction in the U.S., while the opposite is the case for China. The relatively low pollution-abatement effects of carbon mitigation policy in China are primarily due to the expanded role of carbon capture and storage technology, which keeps coal from being crowded out of the energy market by reducing its carbon emission factors, but without affecting NOx and SO2 emissions. Our study suggests that some countries like China may consider it more appealing to pursue the synergy from a pollution-control perspective than from a carbon-mitigation standpoint, given the former’s greater synergistic effects. In this sense, future co-benefit studies need to pay more attention to carbon co-benefits of pollution abatement—the opposite logic of the currently dominant focus.

MIT Global Change

Regional Analysis

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