In year 2000 (t = 0), world reserves of natural gas were roughly 6112 trillion cubic feet In that same year, world consumption of natural gas was roughly 99-6 trillion cubic feet, and was growing exponentially at about 3.1% per year. If demand continues to grow at given rate, and no new reserves of natural gas are found, in what year will world reserves of resource be depleted? World reserves depleted in year.