Exhibit 12.1

Statement of Computation of Ratio of Earnings to Fixed Charges

	Year ended December 31,										Nine months ended September 30,
(in million, except ratios)	2011		2012		2013		2014		2015		2016
Fixed charges:
Interest expensed	$	2,355	$	2,500	$	2,553	$	2,579	$	2,820	$	2,407
Interest capitalized	277		238		197		204		331		153
Interest expensed & capitalized	2,632		2,738		2,750		2,783		3,151		2,560
Preferred stock dividend requirements of subsidiaries	18		18		48		53		47		37
Total fixed charges	2,650		2,756		2,798		2,836		3,198		2,597
Earnings available for fixed charges:
Earnings from continuing operations before income taxes	1,998		2,037		3,930		4,938		3,170		1,644
Add:
Fixed charges	2,650		2,756		2,798		2,836		3,198		2,597
Dividend income of equity investees	204		369		452		674		480		364
	4,852		5,162		7,180		8,448		6,848		4,605
Less:
Interest capitalized	277		238		197		204		331		153
Preferred stock dividend requirements of subsidiaries	18		18		48		53		47		37
Total earnings available for fixed charges	4,557		4,906		6,935		8,191		6,470		4,415
Ratio of earnings to fixed charges	1.7x		1.8x		2.5x		2.9x		2.0x		1.7x