A Forward Looking Version of the MIT Emissions Prediction and Policy Analysis (EPPA) Model

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).This paper documents a forward looking multi-regional general equilibrium model developed from the latest version of the recursive-dynamic MIT Emissions Prediction and Policy Analysis (EPPA) model. The model represents full inter-temporal optimization (perfect foresight), which makes it possible to better address economic and policy issues such as borrowing and banking of GHG allowances, efficiency implications of environmental tax recycling, endogenous depletion of fossil resources, international capital flows, and optimal emissions abatement paths among others. It was designed with the flexibility to represent different aggregations of countries and regions, different horizon lengths, as well as the ability to accommodate different assumptions about the economy, in terms of economic growth, foreign trade closure, labor leisure choice, taxes on primary factors, vintaging of capital and data calibration. The forward-looking dynamic model provides a complementary tool for policy analyses, to assess the robustness of results from the recursive EPPA model, and to illustrate important differences in results that are driven by the perfect foresight behavior. We present some applications of the model that include the reference case and its comparison with the recursive EPPA version, as well as some greenhouse gas mitigation cases where we explore economic impacts with and without inter-temporal trade of permits.This research was supported by the U.S Department of Energy, U.S. Environmental Protection Agency, U.S. National Science Foundation, U.S. National Aeronautics and Space Administration, U.S. National Oceanographic and Atmospheric Administration; and the Industry and Foundation Sponsors of the MIT Joint Program on the Science and Policy of Global Change: Alstom Power (USA), American Electric Power (USA), A.P. Møller-Maersk (Denmark), Cargill (USA), Chevron Corporation (USA), CONCAWE & EUROPIA (EU), DaimlerChrysler AG (USA), Duke Energy (USA), Electric Power Research Institute (USA), Electricité de France, Enel (Italy), Eni (Italy), Exelon Power (USA), ExxonMobil Corporation (USA), Ford Motor Company (USA), General Motors (USA), Iberdrola Generacion (Spain), J-Power (Japan), Merril Lynch (USA), Murphy Oil Corporation (USA), Norway Ministry of Petroleum and Energy, Oglethorpe Power Corporation (USA), RWE Power (Germany), Schlumberger (USA),Shell Petroleum (Netherlands/UK), Southern Company (USA), StatoilHydro (Norway), Tennessee Valley Authority (USA), Tokyo Electric Power Company (Japan), Total (France), G. Unger Vetlesen Foundation (USA)

Green House Gas Mitigation Policy, Bio-fuels and Land-use Change- a Dynamic Analysis

Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy,

Unintended Environmental Consequences of a Global Biofuels Program

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/).Biofuels are being promoted as an important part of the global energy mix to meet the climate change challenge. The environmental costs of biofuels produced with current technologies at small scales have been studied, but little research has been done on the consequences of an aggressive global biofuels program with advanced technologies using cellulosic feedstocks. Here, with simulation modeling, we explore two scenarios for cellulosic biofuels production and find that both could contribute substantially to future global-scale energy needs, but with significant unintended environmental consequences. As the land supply is squeezed to make way for vast areas of biofuels crops, the global landscape is defined by either the clearing of large swathes of natural forest, or the intensification of agricultural operations worldwide. The greenhouse gas implications of land-use conversion differ substantially between the two scenarios, but in both, numerous biodiversity hotspots suffer from serious habitat loss. Cellulosic biofuels may yet serve as a crucial wedge in the solution to the climate change problem, but must be deployed with caution so as not to jeopardize biodiversity, compromise ecosystems services, or undermine climate policy.This study received funding from the MIT Joint Program on the Science and Policy of Global Change, which is supported by a onsortium of government, industry and foundation sponsors

Assessment of U.S. Cap-and-Trade Proposals

The MIT Emissions Prediction and Policy Analysis model is applied to synthetic policies that match key attributes of a set of cap-and-trade proposals being considered by the U.S. Congress in spring 2007. The bills fall into two groups: one specifies emissions reductions of 50% to 80% below 1990 levels by 2050; the other establishes a tightening target for emissions intensity and stipulates a time-path for a "safety valve" limit on the emission price that approximately stabilizes U.S. emissions at the 2008 level. Initial period prices are estimated between $7 and$50 per ton CO2-e with these prices rising by a factor of four by 2050. Welfare costs vary from near zero to less than 0.5% at the start, rising in the most stringent case to near 2% in 2050. If allowances were auctioned these proposals could produce revenue between $100 billion and$500 billion per year depending on the case. Outcomes from U.S. policies depend on mitigation effort abroads, and simulations are provided to illuminate terms-of-trade effects that influence the emissions prices and welfare effects, and even the environmental effectiveness, of U.S. actions. Sensitivity tests also are provided of several of key design features. Finally, the U.S. proposals, and the assumptions about effort elsewhere, are extended to 2100 to allow exploration of the potential role of these bills in the longer-term challenge of reducing climate change risk. Simulations show that the 50% to 80% targets are consistent with global goals of atmospheric stabilization at 450 to 550 ppmv CO2 but only if other nations, including the developing countries, follow suit.

U.S. Greenhouse Gas Cap-and-Trade Proposals: Application of a Forward-Looking Computable General Equilibrium Model

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 develop a forward-looking version of the MIT Emissions Prediction and Policy Analysis (EPPA) model, and apply it to examine the economic implications of proposals in the U.S. Congress to limit greenhouse gas (GHG) emissions. We find that the abatement path and CO2-equivalent (CO2-e) price in the forward-looking model are quite similar to that of the recursive model, implying that the simulation of banking behavior in the recursive model by forcing the CO2-e price to rise at the discount rate approximates fairly well the banking result obtained with the forward-looking model. We find, however, that shocks in consumption path are smoothed out in the forward-looking model and that the lifetime welfare cost of GHG policy is lower than in the recursive model, results we would expect to find given that the forward-looking model can fully optimize over time. The forward-looking model allows us to explore issues for which it is uniquely well-suited, including revenue-recycling, early action crediting, and the role of a technology backstop. We find (1) capital tax recycling to be more welfare-cost reducing than labor tax recycling because of its long term effect on economic growth, (2) potentially substantial incentives for early action credits relative to emission levels in years after a policy is announced but before it is implemented that, however, when spread over the full horizon of the policy do not have a substantial effect on lifetime welfare cost or the CO2-e price, and (3) strong effects on estimates of near-term welfare costs depending on exactly how a backstop technology is represented, indicating the problematic aspects of focusing on short-term welfare costs in a forward-looking model unless there is some confidence that the backstop technology is realistically represented.This study received support from the MIT Joint Program on the Science and Policy of Global Change, which is funded by a consortium of government, industry and foundation sponsors

Balanço de energia na cana-de-açucar irrigada no Submédio São Francisco.

Este trabalho objetivou quantificar fluxo de calor latente e os demais componentes do balanço de energia com base na razão de Bowen (BERB). O estudo foi conduzido de fevereiro/2006 a maio/2007 em um cultivo de cana-de-açúcar variedade RB 92-576 (cana planta), em uma área pertencente Agroindústria do Vale do São Francisco, Juazeiro - BA

Estimativas de parâmetros genéticos de acessos de Myrciaria dubia por marcadores fenotípicos.

O camucamuzeiro (Myrciaria dubia), pertencente à família Myrtaceae, é uma espécie nativa da Amazônia que está em processo de domesticação. O objetivo deste trabalho foi estimar parâmetros genéticos de acessos de camucamuzeiro do Banco Ativo de Germoplasma da Embrapa Amazônia Oriental, por meio de marcadores fenotípicos. Foram avaliados 4? acessos, por meio da amostragem de 40 frutos maduros (epicarpo totalmente roxo) por acesso, nos quais foram mensurados sete caracteres? massa de fruto, comprimento de fruto, diâmetro de fruto, peso da casca, espessura da casca, número de sementes e peso de sementes. Os caracteres, massa de frutos e espessura da casca contribuíram com mais de ?0% para a dissimilaridade. A herdabilidade foi alta para todos os caracteres com destaque para a massa e o diâmetro de fruto, que também apresentaram maiores correlações genéticas. Verificou-se que há variabilidade entre os acessos do BAG de camucamuzeiro e que devido às correlações significativas entre as variáveis podem-se adotar métodos de seleção indireta como ferramenta auxiliar no processo de domesticação e melhoramento desta espécie

Atividade alelopática de extratos brutos de três espécies de Copaifera (Leguminosae-Caesalpinioideae).

Nos últimos anos, atenção especial foi dada aos compostos químicos envolvidos na interação entre plantas, especialmente quando se sabe das possibilidades do seu uso em estratégia de manejo de plantas daninhas. A Amazônia, pela sua megabiodiversidade e abundância de espécies vegetais, pode oferecer excelente oportunidade para a descoberta de inovadoras moléculas químicas com potencial de uso na atividade agrícola. Dessa forma, neste trabalho analisou-se, comparativamente, a atividade potencialmente alelopática de três espécies de Copaifera, caracterizando-se as variações na intensidade dos efeitos alelopáticos em função da espécie doadora, da fração da planta e da polaridade dos constituintes químicos. Extratos hexânico e etanólico, preparados a 1,0% a partir de folhas, galhos e cascas de Copaifera duckei, C. martii e C. reticulata, foram testados sobre a germinação de sementes e o desenvolvimento da raiz das plantas daninhas malícia (Mimosa pudica) e mata-pasto (Senna obtusifolia). Observaram-se variações nas intensidades dos efeitos em função das variáveis estudadas. O extrato etanólico de folhas e o de galhos de C. martii e C. reticulata apresentaram alto potencial para inibir a germinação de sementes, sobretudo da espécie malícia. A espécie C. duckei evidenciou baixo potencial alelopático inibitório na germinação das duas espécies receptoras. Cascas, folhas e galhos de C. duckei apresentaram potencial inibitório mais expressivo sobre o desenvolvimento da raiz, com destaque para as folhas. Compostos químicos apolares e polares estão envolvidos na atividade alelopática da espécie C. duckei, com ênfase maior para os compostos apolares. Diferentemente, para C. martii e C. reticulata, compostos polares estão envolvidos, preferencialmente, na atividade inibitória evidenciada por essas espécies, notadamente aqueles localizados nas folhas e cascas. Comparativamente, a tendência observada foi de que a espécie receptora malícia demonstrou maior sensibilidade aos efeitos alelopáticos dos extratos, especialmente no bioensaio de germinação

Deep Learning Algorithms Improve Automated Identification of Chagas Disease Vectors

This is a pre-copyedited, author-produced version of an article accepted for publication in Journal of Medical Entomology following peer review. The version of record is available online at: https;//doi.org/https://doi.org/10.1093/jme/tjz065Vector-borne Chagas disease is endemic to the Americas and imposes significant economic and social burdens on public health. In a previous contribution, we presented an automated identification system that was able to discriminate among 12 Mexican and 39 Brazilian triatomine (Hemiptera: Reduviidae) species from digital images. To explore the same data more deeply using machine-learning approaches, hoping for improvements in classification, we employed TensorFlow, an open-source software platform for a deep learning algorithm. We trained the algorithm based on 405 images for Mexican triatomine species and 1,584 images for Brazilian triatomine species. Our system achieved 83.0 and 86.7% correct identification rates across all Mexican and Brazilian species, respectively, an improvement over comparable rates from statistical classifiers (80.3 and 83.9%, respectively). Incorporating distributional information to reduce numbers of species in analyses improved identification rates to 95.8% for Mexican species and 98.9% for Brazilian species. Given the ‘taxonomic impediment’ and difficulties in providing entomological expertise necessary to control such diseases, automating the identification process offers a potential partial solution to crucial challenges