Search

Governments worldwide are promoting the development of biofuels in order to mitigate the climate impact of using fuels. In this article, I discuss the impacts of biofuels on climate change, water use, and land use. I discuss the overall metric by which these impacts have been measured and then present and discuss estimates of the impacts. In spite of the complexities of the environmental and technological systems that affect climate change, land use, and water use, and the difficulties of constructing useful metrics, it is possible to make some qualitative overall assessments. It is likely that biofuels produced from crops using conventional agricultural practices will not mitigate the impacts of climate change and will exacerbate stresses on water supplies, water quality, and land use, compared with petroleum fuels. Policies should promote the development of sustainable biofuel programs that have very low inputs of fossil fuels and chemicals that rely on rainfall or abundant groundwater, and that use land with little or no economic or ecological value in alternative uses.

The combustion of fossil fuels is largely responsible for the problems of climate change, air pollution, and energy insecurity. A combination of wind, water, and solar power is the best alternative to fossil fuels, the authors write, because renewable energy sources have near-zero emissions of greenhouse gases and other air pollutants, no long-term waste disposal problems, and no risks of catastrophic accidents. Compared with nuclear energy and biomass energy, the authors find that wind, water, and solar power, alone, would not only be advantageous but also feasible to meet 100 percent of the world’s energy needs. They explain how renewable energy systems can be designed and operated to ensure that power generation reliably matches demand; they calculate that these energy sources would cost less than fossil fuels when all costs to society are considered; and they recommend policies for easing the transition to energy systems based entirely on wind, water, and solar power. [ABSTRACT FROM PUBLISHER]

Highlights • Plans developed to move all energy of 53 towns/cities to 100% clean, renewable. • Proposes electricity or direct heat only, where both from with wind-water-solar. • Transitioning reduces energy, health, and climate costs. • Transitioning creates more permanent, full-time jobs than lost. • Transitioning requires half the end-use energy as current system. Abstract Towns and cities worldwide emit significant pollution and are also increasingly affected by pollution’s health and climate impacts. Local decision makers can alleviate these impacts by transitioning the energy they control to 100% clean, renewable energy and energy efficiency. This study develops roadmaps to transition 53 towns and cities in the United States, Canada, and Mexico to 100% wind, water, and sunlight (WWS) in all energy sectors by no later than 2050, with at least 80% by 2030. The roadmaps call for electrifying transportation and industrial heat; using electricity, solar heat, or geothermal heat for water and air heating in buildings; storing electricity, cold, heat, and hydrogen; and providing all electricity and heat with WWS. This full transition in the 53 towns and cities examined may reduce 2050 air pollution premature mortality by up to 7000 (1700-16,000)/yr, reduce global climate costs in 2050 by $393 (221–836) billion/yr (2015 USD), save each person ∼$133/yr in energy costs, and create ∼93,000 more permanent, full-time jobs than lost. [ABSTRACT FROM AUTHOR]

Life cycle assessment (LCA) is generally described as a tool for environmental decision making. Results from attributional LCA (ALCA), the most commonly used LCA method, often are presented in a way that suggests that policy decisions based on these results will yield the quantitative benefits estimated by ALCA. For example, ALCAs of biofuels are routinely used to suggest that the implementation of one alternative (say, a biofuel) will cause an X% change in greenhouse gas emissions, compared with a baseline (typically gasoline). However, because of several simplifications inherent in ALCA, the method, in fact, is not predictive of real-world impacts on climate change, and hence the usual quantitative interpretation of ALCA results is not valid. A conceptually superior approach, consequential LCA (CLCA), avoids many of the limitations of ALCA, but because it is meant to model actual changes in the real world, CLCA results are scenario dependent and uncertain. These limitations mean that even the best practical CLCAs cannot produce definitive quantitative estimates of actual environmental outcomes. Both forms of LCA, however, can yield valuable insights about potential environmental effects, and CLCA can support robust decision making. By openly recognizing the limitations and understanding the appropriate uses of LCA as discussed here, practitioners and researchers can help policy makers implement policies that are less likely to have perverse effects and more likely to lead to effective environmental policies, including climate mitigation strategies. [ABSTRACT FROM AUTHOR]

Abstract: In this paper I discuss general conceptual issues in the estimation of the impacts of CO2 emissions from soils and biomass, over time, as a result of land-use change (LUC) due to increased demand for energy crops. The effect of LUC on climate depends generally on the magnitude and timing of changes in soil and plant carbon, and in particular on the timing and extent of the reversion of land to original ecosystems at the end of the bioenergy program. Depending on whether one counts the climate impacts of any reversion of land uses, and how one values future climate-change impacts relative to present impacts, one can estimate anywhere from zero to very large climate impacts due to land-use change (LUC). I argue that the best method is to estimate the net present value (NPV) of the impacts of climate change due to LUC. With this approach, one counts the reversion impacts at the end of the program and applies a continuous discounting function to future impacts to express them in present terms. In this case, the impacts of CO2 emissions from the initial LUC then are at least partially offset by the impacts of CO2 sequestration from reversion. [Copyright &y& Elsevier]

Examines the impact of transportation on global climate. Causes of global warming; Impact of climatic concerns on international transportation policies; Proposed tool for analyzing the impact of transportation and other energy systems on climate.

Abstract: "Indirect land use change for biofuels: Testing predictions and improving analytical methodologies" by S. Kim and B. Dale , presents a principal inference not supported by its results, that rests on a fundamental conceptual error, and that has no place in the current discussion of biofuels’ climate effects. The paper takes correlation between two variables in a system with many interacting factors to indicate (or contraindicate) causation, and draws a completely incorrect inference from observed sample statistics and their significance levels. [Copyright &y& Elsevier]