"The rapidly increasing greenhouse gas emissions (GHG) in the world have been proven to contribute to climate change, with dramatic harmful consequences to human communities and many non human animal and plant species. This has led policy makers in many countries to attempt curbing national emissions. The fact that developed and developing countries have different resources, capability and responsibilities (through either burden sharing or effort sharing), and yet are required to cooperate closely if they want to avoid the harmful consequences of climate change, complicates mitigation efforts. Despite this complexity, decisions need to be made and tools developed to aid decision makers. Various information processing tools(such as multi criteria analysis)are used to aid decision making, the most widely used being marginal abatement cost(MAC)curves. MAC curves analyse the mitigation options available to a region or country, the emission reduction potential that would result, and the marginal abatement costs associated with their implementation. The marginal abatement cost is the cost of eliminating an additional unit of emissions. MAC curves are used to compare the cost effectiveness of different mitigation options. These curves show the set of mitigation options available to an economy to achieve increased levels of emissions reduction."