Abstract

Hydrogen (H-2) has been proposed as an alternative energy carrier to reduce the carbon footprint and associated radiative forcing of the current energy system. Here, we describe the representation of H-2 in the GFDL-AM4.1 model including updated emission inventories and improved representation of... Show moreHydrogen (H-2) has been proposed as an alternative energy carrier to reduce the carbon footprint and associated radiative forcing of the current energy system. Here, we describe the representation of H-2 in the GFDL-AM4.1 model including updated emission inventories and improved representation of H-2 soil removal, the dominant sink of H2. The model best captures the overall distribution of surface H-2, including regional contrasts between climate zones, when v(d)(H-2) is modulated by soil moisture, temperature, and soil carbon content. We estimate that the soil removal of H-2 increases with warming (2-4% per K), with large uncertainties stemming from different regional response of soil moisture and soil carbon. We estimate that H-2 causes an indirect radiative forcing of 0.84 mW m-(2)/(Tg(H-2)yr(-1)) or 0.13 mW m(-2) ppbv(-1), primarily due to increasing CH4 lifetime and stratospheric water vapor production. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. Show less