Today, options to reduce the climate impacts of high-speed passenger transport over hundreds of kilometres are limited to using low-carbon synthetic fuels in aviation and high-speed trains. In the future, alternatives like battery electric airplanes might be available. Further, vehicles operating in near-vacuum tubes, so-called “hyperloop systems”, could represent an alternative. Our first-of-its-kind environmental life cycle assessment (LCA), considering its construction, operation, and end-of-life, shows that such a hyperloop system is energy-efficient and can exhibit very low greenhouse gas emissions (<8 g CO₂/pkm) if low-carbon sources provide electricity for its operation and relatively high occupation rates can be realised. The environmental performance of a hyperloop system can be regarded as very similar to that of a train offering the same transport service. Compared to air travel, environmental burdens can be substantially reduced (<5% impact on climate change compared to conventional aircraft). This fundamental finding holds despite uncertainties regarding technical properties and design choices, which reflect the current development status of the hyperloop.