Iceland this month signaled plans to move toward carbon-free domestic flights by the end of the decade, while Sweden's Heart Aerospace aims to deliver an electric plane specifically designed to ply routes linking remote Scandinavian settlements within six years.

Coordinating the region's initiatives is the Nordic Network for Electric Aviation, founded last year and tying together airport authorities and five airlines including Finnair Oyj, Icelandair Group and SAS AB, alongside Heart and other technology innovators. The emphasis on cleaner flights follows Norway's strides toward banishing the combustion engine, with more than half the cars sold there now electric.