Hydrogen does not produce C02 emissions when burned, and so is being touted as a replacement for fossil fuels in everything from heavy industry to aviation and home heating.
But at present the fuel is most commonly produced by extracting it from natural gas, and this process is a huge source of emissions. Manufacturers are planning to deal with this by attaching plants to carbon capture facilities which stash the green house gases created underground, generating what is known as blue hydrogen.
The new paper warns that no carbon capture system developed so far is currently mopping up all emissions. Carbon capture is also energy-hungry in itself, they add, while producing natural gas also leads to methane emissions too.
The paper says: Perhaps surprisingly, the greenhouse gas footprint of blue hydrogen is more than 20pc greater than burning natural gas or coal for heat and some 60pc greater than burning diesel oil for heat.
Our analysis assumes that captured carbon dioxide can be stored indefinitely, an optimistic and unproven assumption. Even if true though, the use of blue hydrogen appears difficult to justify on climate grounds.
The study was led by Professor Robert Howarth at Cornell University and received funding from the Park Foundation in the US, which wants there to be a managed decline in fossil fuels and resists new oil and gas drilling.
Switch to hydrogen fuel could be more polluting than natural gas or coal, academics warn
