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Anthropogenic emissions of greenhouse gases, especially carbon dioxide (CO2), are primarily responsible for the roughly 0.8 °C global temperature increase since the industrial revolution. With industrial activity and population expected to increase for the rest of the century, the projected large increases in greenhouse gas emissions are expected to result in additional, potentially substantial, global warming. Using a powerful, PC-based global climate model, global warming is projected for two business-as-usual cases, as well as simple, yet instructive, scenarios in which major programs are initiated to limit CO2 emissions. The paper provides a brief overview of 1) the forces driving CO2 emission increases, 2) how different CO2 emission trajectories could affect temperature this century, 3) required mitigation technologies with a focus on power generation mitigation options, and 4) R&D priorities. While various aspects of this subject are addressed extensively in the scientific literature,, this paper aims to provide a succinct integration of information about the projected warming of the earth in the decades ahead, the emission reductions that may be needed to constrain this warming to tolerable levels, and the potentially available technologies to help achieve these emission reductions. [ABSTRACT FROM AUTHOR]

Biofuels are fuels produced from biomass, mostly in liquid form, within a time frame sufficiently short to consider that their feedstock (biomass) can be renewed, contrarily to fossil fuels. This paper reviews the current and future biofuel technologies, and their development impacts (including on the climate) within given policy and economic frameworks. Current technologies make it possible to provide first generation biodiesel, ethanol or biogas to the transport sector to be blended with fossil fuels. Still under-development 2nd generation biofuels from lignocellulose should be available on the market by 2020. Research is active on the improvement of their conversion efficiency. A ten-fold increase compared with current cost-effective capacities would make them highly competitive. Within bioenergy policies, emphasis has been put on biofuels for transportation as this sector is fast-growing and represents a major source of anthropogenic greenhouse gas emissions. Compared with fossil fuels, biofuel combustion can emit less greenhouse gases throughout their life cycle, considering that part of the emitted CO2 returns to the atmosphere where it was fixed from by photosynthesis in the first place. Life cycle assessment (LCA) is commonly used to assess the potential environmental impacts of biofuel chains, notably the impact on global warming. This tool, whose holistic nature is fundamental to avoid pollution trade-offs, is a standardised methodology that should make comparisons between biofuel and fossil fuel chains objective and thorough. However, it is a complex and time-consuming process, which requires lots of data, and whose methodology is still lacking harmonisation. Hence the life-cycle performances of biofuel chains vary widely in the** literature. Furthermore, LCA is a site- and time-independent tool that cannot take into account the spatial and temporal dimensions of emissions, and can hardly serve as a decision-making tool either at local or regional levels. Focusing on greenhouse gases, emission factors used in LCAs give a rough estimate of the potential average emissions on a national level. However, they do not take into account the types of crop, soil or management practices, for instance. Modelling the impact of local factors on the determinism of greenhouse gas emissions can provide better estimates for LCA on the local level, which would be the relevant scale and degree of reliability for decision-making purposes. Nevertheless, a deeper understanding of the processes involved, most notably N2O emissions, is still needed to definitely improve the accuracy of LCA. Perennial crops are a promising option for biofuels, due to their rapid and efficient use of nitrogen, and their limited farming operations. However, the main overall limiting factor to biofuel development will ultimately be land availability. Given the available land areas, population growth rate and consumption behaviours, it would be possible to reach by 2030 a global 10% biofuel share in the transport sector, contributing to lower global greenhouse gas emissions by up to 1 GtCO2 eq per year (IEA, 2006), provided that harmonised policies ensure that sustainability criteria for the production systems are respected worldwide. Furthermore, policies should also be more integrative across sectors, so that changes in energy efficiency, the automotive sector and global consumption patterns converge towards drastic reduction of the pressure on resources. Indeed, neither biofuels nor other energy source or carriers are likely to mitigate the impacts of anthropogenic pressure on resources in a range that would compensate for this pressure growth. Hence, the first step is to reduce this pressure by starting from the variable that drives it up, i.e. anthropic consumptions. [ABSTRACT FROM AUTHOR]

The article focuses on policy for energy and sustainable development in developing countries. Energy became a major international issue in the 1970's, following the oil crisis. More recently, global climate change induced by excessive greenhouse gas accumulation in the atmosphere has emerged as a potential problem that further complicates energy issues. In this paper, researchers focus on energy related environmental issues in the developing countries. The development related energy needs of the Third World countries, the potential for better energy management, barriers to reducing greenhouse gas emissions and policies that can improve the performance of developing countries are discussed.