Towards a Safe Hydrogen Economy: An Absolute Climate Sustainability Assessment of Hydrogen Production

Policymakers and global energy models are increasingly looking towards hydrogen as an enabling carrier to decarbonize hard-to-abate sectors (projecting growth in consumption the magnitude of hundreds megatons). Combining scenarios from life cycle impacts different production technologies, results this work show that emissions proposed configurations economy would lead climate overshoot at least 5.4–8.1× defined “safe” space for greenhouse gas by 2050 cumulative 8–12% remaining carbon budget. This suggests a need science-based definition “clean” hydrogen, agnostic technology compatible with development economy. Such deem blue environmentally unviable 2025–2035. The prolific use green is also problematic however, due requirement significant amount renewable energy, associated embedded land, material impacts. These suggest demand-side solutions should be further considered, large-scale transition which represents shift, may still not sufficient humanity into space.