Question: the pre-industrial level of co2 in the atmosphere in ppmv is about
[{'answer': '260 -- 280 ppmv'}, {'provenance': [{'wikipedia_id': '11251601', 'title': "Carbon dioxide in Earth's atmosphere", 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 1127, 'bleu_score': 0.882910591524621, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11580586026791347667}, 'section': 'Section::::Past concentration.:Measuring ancient-Earth carbon dioxide concentration.\n'}]}]