Norway will nearly double its carbon tax on oil companies, a new budget plan revealed on Monday. They plan to raise the carbon tax on the offshore petroleum industry by about $35 per ton in 2013. That would bring the tax up to around $72 per carbon-dioxide ton. The tax will support a new $1.75 billion fund to promote renewable energy and cuts in greenhouse gasses. The fund will also be used to assist developing nations to protect tropical rainforests. Norway has set a goal of reducing greenhouse emissions to 30 percent below its 1990 levels by 2020.