Let's briefly compare the Exxon and BP spills.
So when we talk about how BP's Oil Spill Bill Could Dwarf Exxon's Valdez Tab we should remember that BP's oil spill also dwarfed Exxon's. And is the assertion that the tab is bigger even true? Well, in nominal and real terms, yes.
Cost of the Exxon clean up: $2 billion (1989 dollars) or $3.58 billion (2010 dollars)*
Cost of the BP clean up: $6.1 billion (2010 dollars)
But if we standardize for size of the spill, BP's tab is far too low. Given that the BP spill is more than 15 times larger than the Exxon spill, we should also assume they should spend 15 times more on cleanup than Exxon did, or around $53.7 billion dollars -- $47.6 billion more than BP has spent.