The use of biofuels in domestic transportation sector in the United States and European Union is attributed mainly to the binding mandates, Renewable Fuel Standard in the US and European Directive on the Promotion of Renewable Energy in the EU. The mandates have triggered production of first generation technologies that have been around for centuries and use food crops like corn or sugarcane as inputs and the second generation technologies that are still being developed but rely on cellulose or waste material. This raises important questions, what are the implications of policy mandates and biofuel production on land use change, global food crop prices and fuel blend technology as the binding mandates will rely mainly on first generation fuel technologies for the foreseeable future.

Most analysis of policy mandates and biofuel production technologies leave out the land use change impact assessment. To investigate the questions I focus on how the mandates in the US and EU interact with land use. I use a computable general equilibrium framework, the MIT Emissions Prediction and Policy Analysis (EPPA) model, which captures full economy-wide impacts of policy mandates and land use. I have developed a mechanism to integrate the first and second generation technologies, the transportation sector, and land use for policy impact analysis. I simulated the policy mandates through a permit trading system which is constrained by the blend wall technology of the underlying vehicle transportation fleet.

I find that the global biofuel crop land requirement over 2005 to 2030 time frame is 44 percent higher with the mandates. The land requirement is met primarily by the reallocation of non-biofuel crop land and partially by pasture, natural grass and harvested forest lands. The long term food crop prices increase by less than 1% per year with mandates as land productivity improvements dampen the impact of biofuel production on prices. In the case of global biofuel free-trade Brazil becomes the largest producer which reduces the deforestation in Brazil by 7 percent. I also find that fuel blend-wall acts as an implicit constraint on the domestic biofuel use as it limits the total vehicle fuel consumption.

We evaluate the impact of an economy-wide cap-and-trade policy on U.S. aviation taking the American Clean Energy and Security Act of 2009 (H.R.2454) as a representative example. We use an economywide model to estimate the impact of H.R. 2454 on fuel prices and economic activity, and a partial equilibrium model of the aviation industry to estimate changes in aviation carbon dioxide (CO2) emissions and operations. Between 2012 and 2050, with reference demand growth benchmarked to ICAO/GIACC (2009) forecasts, we find that aviation emissions increase by 130%. In our climate policy scenarios, emissions increase by between 97% and 122%. A key finding is that, under the core set of assumptions in our analysis, H.R. 2454 reduces average fleet efficiency, as increased air fares reduce demand and slow the introduction of new aircraft. Assumptions relating to the sensitivity of aviation demand to price changes, and the degree to which higher fuel prices stimulate advances in the fuel efficiency of new aircraft play an important role in this result.

The direct radiative forcing of black carbon (BC) aerosols is able to cause a significant change in tropical convective precipitation ranging from the Pacific and Indian Ocean to the Atlantic Ocean. This change occurs often well away from emission centers, demonstrating a "remote climate impact." The detailed mechanism of this change has been analyzed in this study. In the tropical Pacific region, the pattern of BC caused precipitation change is found to be similar to the pattern of precipitation anomaly corresponding to the El Niño/Southern Oscillation (ENSO) activities. The BC forced changes in the atmospheric circulation are represented by a strengthened Hadley cell in the Northern Hemisphere, a weakened one in the Southern Hemisphere, an enhancement of the Indian summer monsoon circulation, and a reduction of the lower level easterly wind in the central and east equatorial Pacific. The latter dynamic effect of BC is specifically similar to that of an El Niño event.

© 2007 American Geophysical Union

The emergence of U.S. shale gas resources to economic viability affects the nation’s energy outlook and the expected role of natural gas in climate policy. Even in the face of the current shale gas boom, however, questions are raised about both the economics of this industry and the wisdom of basing future environmental policy on projections of large shale gas supplies. Analysis of the business model appropriate to the gas shales suggests that, though the shale future is uncertain, these concerns are overstated. The policy impact of the shale gas is analyzed using two scenarios of greenhouse gas control—one mandating renewable generation and coal retirement, the other using price to achieve a 50% emissions reduction. The shale gas is shown both to benefit the national economy and to ease the task of emissions control. However, in treating the shale as a "bridge" to a low carbon future there are risks to the development of technologies, like capture and storage, needed to complete the task.

© 2012 IAEE