With wholesale prices for natural gas doubling in the last year, environmental concerns are taking a back seat as energy companies make plans to build one, maybe two, pipelines to carry gas from beneath the Arctic Ocean to population centers. Native groups that once opposed development are now seeing economic opportunities. Greenpeace opposes the idea of gas pipelines, saying North Americans should instead invest the $10 billion or so it would take to build two pipelines in alternative energy sources like solar and wind. Other environmental groups see some advantage to increasing the continent’s supply of natural gas, which when burned produces much less carbon dioxide than coal and oil. Aboriginal leaders don’t much care for Greenpeace, blaming the group’s anti-fur campaigns for destroying their traditional hunting and trapping economies.