SIOUX FALLS, S.D. (AP) — Two companies seeking to build thousands of miles of pipeline across the Midwest are promising the effort will aid rather than hinder the fight against climate change. Some environmental groups remain skeptical. The pipelines would stretch from North Dakota to Illinois, potentially transforming the Corn Belt into one of the world’s largest corridors for a technology called carbon capture and storage. The projects would capture the greenhouse gas carbon dioxide at ethanol refineries and transport it to sites where it could be buried thousands of feet underground beneath deep geological formations. But that isn’t stopping some conservationists from opposing it, raising the chances that the pipelines become another pitched battle between energy companies and environmentalists.