The following table describes changes to the Corporation’s asset retirement obligations:
| 2013 | 2012 | |||||||
| (In millions) | ||||||||
|
Asset retirement obligations at January 1 |
$ | 2,661 | $ | 2,071 | ||||
|
Liabilities incurred |
42 | 186 | ||||||
|
Liabilities settled or disposed of |
(576 | ) | (324 | ) | ||||
|
Accretion expense |
129 | 135 | ||||||
|
Revisions of estimated liabilities |
573 | 529 | ||||||
|
Foreign currency translation |
(57 | ) | 64 | |||||
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Asset retirement obligations at December 31 |
2,772 | 2,661 | ||||||
|
Less: Current obligations |
523 | 449 | ||||||
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Long-term obligations at December 31 |
$ | 2,249 | $ | 2,212 | ||||
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