Experts in the airline industry estimate these eco-friendly options will contribute to roughly 65% of emission reductions.
Hydrogen may have lost the race to fuel electric cars but it looks a likely contender to replace fossil fuels in trucks, ships, planes and heavy industry.
Ambitious Danish project plans to deliver green hydrogen at scale.
Former Unilever CEO brands Ryanair one of the most unethical and polluting companies in Europe.
Could we finally have a solution to cut emissions from aviation in the shape of the hyperloop technology?