Angelo Costa Gurgel

Indirect Emissions from Biofuels: How Important?

Biofuel Backfire For compelling economical, geopolitical, and environmental reasons, biofuels are considered an attractive alternative to fossil fuels for meeting future global energy demands. Melillo et al. (p. 1397, published online 22 October), however, suggest that a few serious drawbacks related to land use need to be considered. Based on a combined biogeochemistry and economic model, indirect land use (for example, clearing forested land for food crops to compensate for increased biofuel crop production on current farmlands) is predicted to generate more soil carbon loss than directly harvesting biofuel crops. Furthermore, increased fertilizer use for biofuels will add large amounts of nitrous oxide—a more effective heat-trapping molecule than carbon dioxide—to the atmosphere. Policy decisions regarding land and crop management thus need to consider the long-term implications of increased biofuel production. Land-use changes associated with biofuel production are predicted to increase greenhouse gas emissions. A global biofuels program will lead to intense pressures on land supply and can increase greenhouse gas emissions from land-use changes. Using linked economic and terrestrial biogeochemistry models, we examined direct and indirect effects of possible land-use changes from an expanded global cellulosic bioenergy program on greenhouse gas emissions over the 21st century. Our model predicts that indirect land use will be responsible for substantially more carbon loss (up to twice as much) than direct land use; however, because of predicted increases in fertilizer use, nitrous oxide emissions will be more important than carbon losses themselves in terms of warming potential. A global greenhouse gas emissions policy that protects forests and encourages best practices for nitrogen fertilizer use can dramatically reduce emissions associated with biofuels production.

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

In 2007 the US Congress began considering a set of bills to implement a cap-and-trade system to limit the nations greenhouse gas (GHG) emissions. The MIT Integrated Global System Model (IGSM)—and its economic component, the Emissions Prediction and Policy Analysis (EPPA) model—were used to assess these proposals. In the absence of policy, the EPPA model projects a doubling of US greenhouse gas emissions by 2050. Global emissions, driven by growth in developing countries, are projected to increase even more. Unrestrained, these emissions would lead to an increase in global CO2 concentration from a current level of 380 ppmv to about 550 ppmv by 2050 and to near 900 ppmv by 2100, resulting in a year 2100 global temperature 3.5–4.5°C above the current level. The more ambitious of the Congressional proposals could limit this increase to around 2°C, but only if other nations, including developing countries, also strongly controlled greenhouse gas emissions. With these more aggressive reductions, the economic cost measured in terms of changes in total welfare in the United States could range from 1.5% to almost 2% by the 2040–2050 period, with 2015 CO2-equivalent prices between

Using land to mitigate climate change: hitting the target, recognizing the trade-offs.

30 and

Regional, multilateral, and unilateral trade policies on MERCOSUR for growth and poverty reduction in Brazil

55, rising to between

Life Cycle Greenhouse Gas Emissions of Sugar Cane Renewable Jet Fuel

120 and

Impactos da liberação comercial de produtos do agronegócio na rodada de Doha

210 by 2050. This level of cost would not seriously affect US GDP growth but would imply large-scale changes in its energy system.

An analysis of US greenhouse gas cap-and-trade proposals using a forward-looking economic model

Land can be used in several ways to mitigate climate change, but especially under changing environmental conditions there may be implications for food prices. Using an integrated global system model, we explore the roles that these land-use options can play in a global mitigation strategy to stabilize Earths average temperature within 2 °C of the preindustrial level and their impacts on agriculture. We show that an ambitious global Energy-Only climate policy that includes biofuels would likely not achieve the 2 °C target. A thought-experiment where the world ideally prices land carbon fluxes combined with biofuels (Energy+Land policy) gets the world much closer. Land could become a large net carbon sink of about 178 Pg C over the 21st century with price incentives in the Energy+Land scenario. With land carbon pricing but without biofuels (a No-Biofuel scenario) the carbon sink is nearly identical to the case with biofuels, but emissions from energy are somewhat higher, thereby results in more warming. Absent such incentives, land is either a much smaller net carbon sink (+37 Pg C - Energy-Only policy) or a net source (-21 Pg C - No-Policy). The significant trade-off with this integrated land-use approach is that prices for agricultural products rise substantially because of mitigation costs borne by the sector and higher land prices. Share of income spent on food for wealthier regions continues to fall, but for the poorest regions, higher food prices lead to a rising share of income spent on food.

Impactos da política americana de estímulo aos biocombustíveis sobre a produção agropecuária e o uso da terra

The authors estimate that the Free Trade Agreement of the Americas (FTAA), the EU-MERCOSUR agreement, and multilateral trade policy changes will all be beneficial for Brazil. The Brazilian government strategy of simultaneously negotiating the FTAA and the EU-MERCOSUR agreement, while supporting multilateral liberalization through the Doha Agenda, will increase the benefits of each of these policies. The authors estimate that the poorest households typically gain roughly three to four times the average for Brazil from any of the policies considerethe United States protects its most highly protected markets. Both the FTAA and the EU-MERCOSUR agreements are net trade-creating for the countries involved, but excluded countries almost always lose from the agreements. The authors estimate that multilateral trade liberalization of 50 percent in tariffs and export subsidies results in gains to the world more than four times greater than either the FTAA or the EU-MERCOSUR agreement. This shows the continued importance to the world trading community of the multilateral negotiations.

Brazilian trade policies: some observed and estimated effects of the 1990s liberalization

This study evaluated the life cycle GHG emissions of a renewable jet fuel produced from sugar cane in Brazil under a consequential approach. The analysis included the direct and indirect emissions associated with sugar cane production and fuel processing, distribution, and use for a projected 2020 scenario. The CA-GREET model was used as the basic analytical tool, while Land Use Change (LUC) emissions were estimated employing the GTAP-BIO-ADV and AEZ-EF models. Feedstock production and LUC impacts were evaluated as the main sources of emissions, respectively estimated as 14.6 and 12 g CO2eq/MJ of biofuel in the base case. However, the renewable jet fuel would strongly benefit from bagasse and trash-based cogeneration, which would enable a net life cycle emission of 8.5 g CO2eq/MJ of biofuel in the base case, whereas Monte Carlo results indicate 21 ± 11 g CO2eq/MJ. Besides the major influence of the electricity surplus, the sensitivity analysis showed that the cropland-pasture yield elasticity and the choice of the land use factor employed to sugar cane are relevant parameters for the biofuel life cycle performance. Uncertainties about these estimations exist, especially because the study relies on projected performances, and further studies about LUC are also needed to improve the knowledge about their contribution to the renewable jet fuel life cycle.

Avaliação de políticas comerciais em modelos de equilíbrio geral com pressuposições alternativas quanto aos retornos de escala

O presente trabalho mensura os impactos de reducoes multilaterais de barreiras comerciais aos produtos do agronegocio, atraves de um modelo aplicado de equilibrio geral. Os resultados sugerem que as discussoes da Rodada de Doha deveriam focalizar a reducao tarifaria como o principal tema da negociacao em torno dos produtos agropecuarios. Uma repeticao dos cortes tarifarios da Rodada do Uruguai frustraria o objetivo de acesso a mercados, devido a grande diferenca entre tarifas consolidadas e tarifas aplicadas em varios paises. A implementacao da formula suica de reducao tarifaria traz ganhos potenciais elevados para o Brasil e para o mundo.