As she sat down to pen her first email to BP’s 100,000 staff, Meg O’Neill opted against sparing the radical rhetoric. To the American oil and gas thoroughbred, who had just become the first ever female chief executive of a British energy major, there was only one course available to her new employer should it wish to avoid extending its more-than-decade-long spell of financial mediocrity. “Right now, we’re operating in an environment of significant complexity: geopolitical tension; conflict; rapid technological change; and…