The air transport sector is enjoying an optimistic growth rate while at the same time eliciting growing concern, due to its environmental impact and its vulnerability with respect to energy security. These issues have put the sector at the forefront of the tide in achieving energy efficiency. Efforts have been made on every front to improve efficiency through better technology, optimized operation, as well as energy-saving infrastructure. What is the low-hanging fruit that the air transport sector can reach in terms of energy efficiency? What are the policy makers’ and private sector’s roles in achieving energy efficiency in air transport? These are the issues that this report would like to address in this energy- and finance-constrained economy. This report includes five chapters. Chapter 1 will introduce the air transport energy consumption outlook though the analysis of the growth of air services as well as consumption of fossil fuel-based energy. Chapter 2 will discuss air transport’s impact on the environment and the response and actions from the air transport sector. Chapter 3 will detail potential energy efficiency gains in aircraft design, air service operation, as well as infrastructure design. The role of the government and private sector in fostering and supporting those energy efficiency gains will also be discussed. Chapter 4 will enumerate policy options for countries with respect to air transport energy efficiency, focusing on fiscal measures. Finally, Chapter 5 presents an analysis of support and financing measures that can be taken by the World Bank and its member countries.