The disastrous BP oil spill is now believed to be the worst environmental disaster in U.S. history.

Even worse than Exxon Valdez. Exxon Valdez stirs up strong memories. Who can forget the images of birds covered in black oil slick? Imagine an Exxon Valdez happening every year for 50 years. Pretty unimaginable.

Yet, this is what residents of Nigeria’s oil-producing Niger Delta have been living with for the last 50 years.

Experts estimate that some 13 million barrels of oil have been spilt in the Niger Delta since oil exploration began in 1958. This is the equivalent of one Exxon Valdez every year for 50 years.

Although the Obama administration has come under much criticism for not responding quickly enough, nor adequately, to the BP oil spill, there is no denying that top government officials, including the president himself, have felt compelled to speak about the spill and to insist that BP will be held accountable.