More than 50 European and U.S. scientists have written to the president of the European Commission to urge him to go forward with a law that would label tar sands oil as 25 percent more polluting than other forms of oil. The law, which has been in limbo since it was approved by EU member states in 2009, has faced significant criticism from oil companies such as Total and BP. Canada—the world’s biggest producer of oil from tar sands—has headed the opposition to the law. According to Canada’s Natural Resources Minister Joe Oliver, oil from tar sands would be “stigmatized” by the EU law, and the country has even threatened a trade war with the EU over the proposed legislation. In the letter, the scientists combatted criticism of the law, confirming that it is scientifically sound and saying that the policy would ensure investment in cleaner fuels. For the full story, see and For more on the threat of a trade war, see