- Biogas sources
The Copenhagen Accord reiterates the international community’s commitment to ‘hold the increase on global temperature below 2 degrees Celsius’ to avoid dangerous climate change impacts. This presents an immense challenge for Asian countries currently experiencing rapid economic growth, coupled with greater energy consumption. There is evidence that climate change is affecting Asia through increases in the intensity and frequency of weather related events such as heat waves, tropical cyclones, drought, intense rainfall, flooding and severe dust storms.
Recent research suggests that black carbonBlack Carbon (BC) has emerged as a major contributor to global climate change, possibly second only to CO2 as the main driver of change. BC particles strongly absorb sunlight and give soot its black colour. BC is produced both naturally and by human activities as a result of the incomplete combustion of fossil fuels, biofuels etc. Primary sources include emissions from diesel engines, wood burning and forest fires. is influencing rainfall patterns and the Asian monsoon . Above a rise of two degrees in global temperature, extreme weather events are predicted to worsen, the availability and quality of water resources to reduce, crop yields to fall and heat stress and vector borne diseases to harm human health. Scientific studies indicate that low-lying coastal areas in Asia, including small islands, are more sensitive to the effects of sea-level rise and storm surge . Countries like Indonesia, the Philippines, Thailand and Vietnam could experience combined damage equivalent to more than 6% of their gross domestic product each year by the end of this century as a result of climate change .
Road transport is the fastest growing contributor of greenhouse gas emissions in Asia, mainly through the release of CO2 from the combustion of fossil fuels. Black carbon particles and ground level ozone are other potent climate warming agents associated with motor vehicle emissions. A growing source of greenhouse emissions in Asia is methaneMethane is the main component of natural gas, and is an important source of energy. However, it is also a potent greenhouse gas that remains in the atmosphere for approximately 9-15 years. Methane is over 20 times more effective in trapping heat in the atmosphere than carbon dioxide (CO2) over a 100-year period and is emitted from a variety of natural and human-influenced sources including landfills, natural gas and petroleum systems, agricultural activities, coal mining, stationary and mobile combustion and wastewater treatment. arising from the disposal of organic waste at landfill sites. Methane is twenty three times more powerful a greenhouse gas than CO2.
Strategies aimed at mitigating greenhouse gas and air pollution emissions could achieve more successful results in tackling climate change according to a recent UNEP report. Decarbonising road transportation through the use of biomethane as a low emission vehicle fuel can deliver such a solution in Asian cities.
Biomethane has the lowest lifecycle GHG emissions compared with other vehicle fuels and is considered carbon neutralAt best, carbon neutral means using only renewable energies that do not produce any carbon dioxide. However, it also refers to achieving net zero carbon emissions by balancing carbon dioxide released into the atmosphere from burning fossil fuels, for example petrol, with renewable energy that creates a similar amount of useful energy, so that the carbon emissions are compensated for. It can also refer to carbon offsetting, the practice of paying others to remove 100% of the carbon dioxide emitted from the atmosphere, for example by planting trees, or by purchasing carbon credits (any tradable certificate or permit representing the right to emit one tonne of carbon dioxide or its equivalent).. It produces lower CO2 and black carbon exhaust emissions compared to conventional fuels. The manufacture of biomethane involves capturing methane emission from landfill sites which would otherwise be released to the atmosphere. Unlike diesel and petrol, producing biomethane eliminates the requirement for energy intensive fuel extraction and refining processes. Furthermore the manufacture of biomethane avoids greenhouse gas emissions associated with changing land use to grow crops for producing liquid biofuelsThe two main types of liquid biofuel are biodiesel and bioethanol. Biodiesel can be blended with diesel and bioethanol is primarily blended with petrol. At present, the main vegetable oil used for biodiesel comes from oilseed rape, and bioethanol is produced from sugar beet or cereal grains..
 IPCC Fourth Assessment Report: Climate Change, 2007
 UNEP – Integrated Assessment of Black Carbon and Tropospheric Ozone, 2011
 Asian Development Bank, Reducing Carbon From Transport Projects, 2010