A carbon tax, applicable to all hydrocarbon compounds, was inaguarated in December 1998 (Law 448/1998). The Law established the value of the excise taxes for 1999 (0.52 ? per metric ton of coal, petroleum coke and ?orimulsion? used in combustion plants) and those for 2005, to be reached progressively. The increases between 1999 and 2004 were to be decided on a yearly basis by the Government and set by decrees of the President of the Ministers Cabinet. In September 2000, Decree 268/2000 suspended the CO2 tax increases. A 30 December 2004 law, Number 311, canceled the provision entirely.