Some people worry about the amount of oil and gas that remain beneath Earth's surface; others' concern is about the amount of subsurface resources Earth's governments will allow access to. "Our Earth was endowed with 3 trillion barrels of conventional oil," Stuart McGill, senior vice president, ExxonMobil Corp., said at the annual Cambridge Energy Research Associates conference in Houston last month. "With unconventional, that has been pushed to 4 trillion barrels. Since the dawn of human history, we have only consumed 1 trillion barrels. The oil is there. It is the geopolitical forces that will decide the future." George Kirkland, executive vice president, upstream and gas, Chevron Corp., said the world has enough hydrocarbons to last many years based on technology and new frontiers that will step in to fill the gap in future supply and demand. "It is the role of the government to create an environment where energy companies can apply their resources robustly and reliably," he said. "The U.S. is sending mixed messages in terms of energy policy. In 2005, the energy policy encouraged exploration and production, and conservation. In 2006, Congress is considering the abolition of foreign tax credits, making us less competitive in the foreign marketplace." McGill added that the public's perception of the industry it relies on is of considerable importance to the future of the energy industry. "We in the industry have a duty to share information about the fundamental workings of our business, while those in government have a duty to act on that information," he said. "Oil by nature is a commodity, and prices in general reflect the market perception of the world balance of supply and demand at any given moment." The perception and reality of the way the economy of oil works is very different in that it cannot realistically be compared with any other economy because of its enormous scale, McGill said. "The resulting perception/reality gap leads to bad public policy," he said. Another gap in perception and reality is that the public sees energy companies' earnings as being far too much, but overlooks the fact that energy companies use today's earnings to make investments for the world's future energy needs, McGill said. "Another misperception is any nation can achieve energy independence," he said. "This is just not feasible for any time period relative to this discussion." Instead of energy independence, McGill called for energy interdependence: it is better for the economy, would remove barriers to trade and would reduce taxes and allow all of the world's economies to better react to the disruptions in supply that often occur. "The most effective policies will help create an investment environment that will stimulate competition," he said. "Providing the industry with more latitude will allow us to innovate, turning so-called unconventional resources into conventional ones. Resisting the temptation to tamper with the markets when prices go up will allow the markets to work."