Exhibit 12

RATIO OF EARNINGS TO FIXED CHARGES

December 31, 2015

	Years Ended December 31,
	2015			2014			2013			2012			2011
	(Millions, except ratio amounts)
Earnings (loss) from continuing operations before income taxes	$	(21,268	)	$	4,059		$	149		$	(317	)	$	4,290
Capitalized interest, net of amortization		17			(13	)		(4	)		(2	)		(26	)
		(21,251	)		4,046			145			(319	)		4,264
Fixed charges:
Interest expensed and capitalized		585			606			493			454			424
Estimate of interest within rental expense		29			20			8			14			14
Total fixed charges		614			626			501			468			438
Earnings available (insufficient) for payment of fixed charges	$	(20,637	)	$	4,672		$	646		$	149		$	4,702
Ratio of earnings to fixed charges		N/A		$	7.46		$	1.29			N/A		$	10.74
Insufficient earnings to fixed charges	$	21,251			N/A			N/A		$	319			N/A

N/A    Not applicable.