Guardian: Saudi Arabia warned today that the world could be facing another oil shock, with prices back above the record highs of almost $150 a barrel within two to three years. The comments from the Saudi oil minister at an energy summit in Rome were echoed by the IMF, both blaming lower prices and the global recession for hampering investment in new capacity. Prices have fallen back from the peak they reached last year, largely because of the fall in demand in the downturn, and are …