This paper presents a life cycle assessment for three stationary energy storage systems (ESS); lithium iron phosphate (LFP) battery, vanadium redox flow battery (VRFB) and liquid air energy storage (LAES). The global warming potential (GWP) is assessed in relation to uncertainties in usage of the storage, use-phase energy input, cell replacement and round trip efficiency parameters. Relative climate change mitigation potential in comparison with equivalent diesel-electric and natural gas generation is discussed, as is the effect of recycling at end of life. With variations in input electricity source, recycling and efficiency, the life cycle global warming potential for LFP ranges from 185 kg CO2eq/MWh to 440 kg CO2eq/MWh; for VRFB from 121 kg CO2eq/MWh to 443 kg CO2eq/MWh; and for LAES from 48 kg CO-2eq/MWh to 203 kg CO2eq/MWh. In all cases there are climate change mitigation benefits compared to fossil fuel alternatives. Use of renewable energy for charging and operation, ease of component recycling/reuse and reduced parts replacement is shown to reduce GWP. The climate change mitigation potential of ESS for electricity grid operation is further enhanced by increasing use of the storage assets. Recycling of ESS is shown to reduce terrestrial acidification, freshwater eutrophication and particulate matter impacts. Reduced ozone depletion potential for VRFB and LFP can be achieved by reducing nafion and PVDF components respectively.