Oil prices rose about 2% today over concerns of a global energy supply crunch. Severe cold weather across the U.S. is limiting crude oil output in North Dakota, as well hampering production in other states, said Phil Flynn, analyst with Price Future Group. Meanwhile Global oil production is higher while the growth outlook in China and Europe is mixed and data this week is expected to show U.S. economic growth has slowed considerably, he said. “Investors want to be bullish, but tepid data and a cautious narrative from policymakers keep them on the back foot,” said Tamas Varga of oil broker PVM. WTI traded down up $1.78 or 2.4% to close at $75.19. Brent traded up $1.50 or 1.9% to close at $80.06.