Assessing the carbon footprint of road projects and related sustainability initiatives in Abu Dhabi - technical report I: literature review

Energy consumption and the CO2 emission rates in the world are increasing dramatically. Climate change has emerged as an important threat to economic development, environment, and public health. Greenhouse gases are the gases that trap heat in our atmosphere, creating what we call the 'greenhouse effect', that leads to warming the planet Earth. Human activities are contributing several types of greenhouse gases to the atmosphere. The six GHGs identified by the Kyoto Protocol are Carbon Dioxide (CO2), Methane (CH4), Nitrous oxide (N2O), Hydrofluorocarbons (HFC), Perfluorinated compounds (PFC), and Sulfur hexafluoride (SF6). Each one of these gases can stay in the atmosphere for different amounts of time that can range from a few years to thousands of years. According to the International Panel for Climate Change (IPCC), the total GHG emissions back in 2010 was 49.5 GtCO2eq. The transportation sector is one of the major contributors to global climate change through emissions of CO2 and other GHGs. About 23% of energy-related CO2 emission is contributed by the transportation sector. About 72% of the total direct and indirect GHGs emissions of the transportation sector is caused by roads, making it the top contributing sub-sector in the transportation sector. In the Abu Dhabi Emirate, the total GHG emissions in 2010 were 99,101 Gg CO2 eq. The transportation sector accounted for about 19% of the total emissions and about 63% of the transportation emissions were originated from roads. One of the major strategies to decrease air pollution is to reduce carbon footprint, which can be defined as the total amount of CO2 and other GHGs emitted over the full life cycle of a product or project. As such, for road projects, carbon footprint should be calculated for its life cycle. Sources of carbon emission in road include construction materials, fuel consumption, removal of vegetation and uses of machinery and vehicles. Even though roads often bring major economic and social benefits, they can have a considerable negative impacts on both the community and the surrounding natural environment. These methodologies of CO2 emissions estimation can be divided into three groups. The first and most important group consists of standards and standard-like guidelines that are widely accepted and used. The second group comprises guidelines that focus especially on transport or logistics, but they are often to some extent limited, for example limited to national, regional or mode-specific context. The third group covers industry-led schemes and programs that provide guidelines for a specific branch of industry as how to calculate the carbon footprint. After a careful study of each one of these groups and how some other countries utilized them in their carbon footprint calculation, a selection of one of those groups was made and a modification process took place to allow us to use the method in the Abu Dhabi Emirate. It also helped in determining the best available carbon footprint calculating tool. International cooperation and local action are necessary to mitigate the CO2 emissions. The Government of the United Arab Emirates joined the forces with the international movement towards a clean, sustainable, and environmentally friendly world. The UAE is now fully committed to the United Nations Framework Convention on Climate Change, and creating new laws and regulations to be able to do so. This project is part of the UAE efforts towards making its roads more environmentally sustainable