Originally Posted by number_6

In actuality the UAE has the 4th largest known oil reserves in the world and at current production rates the proven oil reserves would last 150 years. The urban legend that Dubai will run out of oil within a decade or 2 is from the situation in 1991, when the then-proven oil reserves were sufficient until 2016. They've found quite a bit of oil since then.

The ruler of UAE also happens to own much of the oil, Emirates airlines and quite a bit of the real estate. Leading to the plan to make Emirates one of the biggest airlines in the world (look at their airplane orders for the next decade, more than all US airlines combined at the moment) and use the oil money to develop a dominant tourism, trade and commerce industry. Plus act as a tax haven for celebrities, with real estate to match. In that context their airport construction, including a few hundred million throw away dollars, is a drop in the bucket. Given the incredibly high valuations of airports in today's world, that seems like a great investment and not money down the drain (BAA, the company that runs LHR/LGW and a couple of other airports, is valued at USD 14 billion, for example).