Prince Turki went on to elaborate that the Kingdom opposes extending financial assistance to energy sources such as coal or nuclear energy while high taxes are imposed on petroleum. Saudi Arabia, he affirmed, has raised its productive capacity, and is participating in the process of oil refining, in addition to building huge oil tankers. Billions of dollars have been invested in the petroleum industry globally in order to render petroleum products harmless to the environment; coal, on the other hand pollutes the environment, and nuclear energy is fraught with danger.