The energy industry is rising to the challenge of a hydrogen economy. For many, it is essential to a clean energy future. Hydrogen can be produced in several ways, but if it is to help in the battle with climate change, the hydrogen produced will need to be low carbon.

Blue hydrogen will generally have a larger greenhouse gas footprint compared to green hydrogen since not all emissions from hydrogen production can be abated. However, the actual emissions will vary greatly depending on chosen technologies and processes within the entire value chain.

In this brief we explore the greenhouse gas footprint of different blue hydrogen processes and supply chains, and what it takes for blue hydrogen to meet thresholds as set by the taxonomies developed by the EU and the World Business Council for Sustainable Development (WBCSD).

We find that blue hydrogen can be delivered with a lower greenhouse gas (GHG) footprint than the thresholds in the taxonomy as defined by the EU and WBCSD and be classified as low carbon. However, this requires a combination of hydrogen production technology and carbon capture that focuses on high conversion rates and high CO ₂ capture rates, resulting in low process related CO ₂ and methane emissions. In addition, the natural gas supply chain emissions of CO ₂ and methane must be kept low. Our data show that this can be delivered with current natural gas supply in some regions, but far from all.