How does the melting ice cap affect the extraction of oil, natural gas and minerals

During the summer of 2012, it was reported that the Arctic Ocean melted to the lowest level since the satellites began keeping track of ice over the North Pole in 1979.

While this threatens the environmental activists, the thirsty oil industry saw the event as another opportunity, as the US Geological Survey stated that there may be more than 90 billion barrels of recoverable oil buried in the Arctic. The amount is said to cover about 13% of the world's estimated undiscovered reserves. 

As ironic as it gets, burning of fuel oils led to climate change, which in turn contributed greatly to the melting of the ice caps. And now, the various oil companies have sent their drilling ships northward to drill, produce and burn more oil, that would eventually make our climate even warmer. 

If the experiment was perfomed more then once and you get the same results