By Noah Browning LONDON (Reuters) -The global oil market is “walking a tightrope” between scarce supply and the possibility of a recession, the International Energy Agency (IEA) said on Wednesday, with higher prices and worsening economic conditions already taking a toll on demand. The cloudy outlook is reflected in volatile trading, with Brent crude falling 7% to below $100 a barrel on Tuesday as futures traders worried over an economic contraction but high physical oil prices still indicate strong demand for now. “Rarely has the outlook for oil markets been more uncertain. A worsening macroe…