Many countries keep their reserves a secret, meaning the price of oil is based on a huge amount of guesswork. Peak oil, if it even exists , is very much a moving target . But so, it turns out, is measuring how much oil is already above ground, sitting in the holds of ships and in storage facilities around the world. It’s not that humanity is fundamentally incapable of measuring how much oil we are extracting—it’s that many countries don’t report their inventories. Take China, for example, which has been buying up far more oil than it appears to be using. As the Wall Street Journal reports , analysts think that 160 million barrels of surplus, enough to supply the country for two weeks, has gone to one of two places: either commercial storage, or to build up the nation’s strategic oil reserves. If it’s the latter, China’s demand […]