Big Oil firms expect global oil demand to stop growing at some point early next decade. But the decline will be very slow and gradual and will look more like a plateau than a downward spiral. The world’s biggest international oil and gas companies have started to acknowledge that demand growth could slow or stop within a decade. But these firms keep pumping oil and gas more than they did earlier this decade as they expect that oil demand – regardless of a peak – isn’t going anywhere. Big Oil’s…