Airships have yet to reemerge as commercial transport, despite their numerous ecological, humanitarian, security, and business applications. A barrier for some business models is the regulation of lifting gasses. Regulations in many countries require airships to use helium to generate vertical movement, or lift. As supplies diminish, helium gas has become dramatically more expensive.
When the last batch of legal writers on airships were writing, helium was only eight times more expensive than hydrogen, but its non-flammable nature meant it was perceived as safer and therefore desirable. Hydrogen offers a potential business solution to the problem of rising fuel costs and carbon emissions, but the legal landscape for hydrogen as a lifting gas, around the world, is not well harmonized.
Business and governmental interest has resurfaced for airships because of increased scrutiny being given to aviation carbon emissions. The International Civil Aviation Organization (ICAO), a specialized agency of the United Nations in charge of international air navigation, has promulgated the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) regime. CORSIA “is the first global market-based measure for any sector and represents a cooperative approach that moves away from a “patchwork” of national or regional regulatory initiatives,” and instead into an international harmonization of initiatives to reduce carbon in international aviation.