OPEC is one of the best examples. OPEC， the Organization of Petroleum Exporting Countries， is an international organization of eleven developing countries that are heavily reliant on oil revenues as their main source of income. Since oil revenues are so vital for the economic development of these nations， they aim to bring stability and harmony to the oil market by adjusting their oil output to help ensure a balance between supply and demand. In the long run， the stabilized out-put help to cease the problem of over-refining and over utilization of oil energy.
Nowadays， developed countries already masters the technology of using more efficiency and economical energy resources， such as water and solar energy， while the traditional and wasted energy still dominates in the developing countries. International cooperation enables the technology transfer between developed countries and developing countries and devotes to the benefit of entire human beings. A worldwide leader can speed up the decision-making progress and enhance the solidarity among the member countries.