But this hydrogen is extracted in a process involving fossil fuels ​ — a process that also gives off the poisonous gas carbon monoxide and the greenhouse gas carbon dioxide.
Ent vesiniku tootmisprotsessis kasutatakse fossiilseid kütuseid, mille tagajärjel tekib mürkgaas süsinikmonooksiid ja kasvuhoonegaas süsinikdioksiid.