| 1 | Other sources, untapped as yet, include Greenland. | |
| 2 | More rain and snow fall on Greenland in the winter. | |
| 3 | Denmark also has 2 autonomous provinces - the Faroe Islands and Greenland. | |
| 4 | Similar surveys have been conducted in Greenland, Iceland and Alaska. | |
| 5 | But the presence of ammonium in Greenland ice cores at both times is accepted. |