BP in 2020 set out its ambition to become a net zero company "by 2050 or sooner."BP shares dropped on Tuesday after the firm flagged it expects to post an impairment of up to $2 billion in the second quarter and warned of lower refining margins weighing on its results.BP shares dropped 3% in early market trading at 08:18 a.m. London time.In a Tuesday statement, the company said it anticipates weak refining margins and oil trading performance will weigh on its second-quarter results, due out on 30 July. The ...