Meeting 2050 emissions goals requires the rapid phase-down of fossil fuels. Much of this can be accomplished through direct electrification. For example, fossil-fuel-burning passenger vehicles and furnaces can be replaced with electric vehicles and heat pumps. As we electrify end-uses, we must also replace coal, oil, and natural gas power plants with wind farms and solar arrays. And we need to upgrade our electric infrastructure—transmission lines, battery storage facilities, and vehicle charging stations—to accommodate increased demand and variable renewable generation.
Direct electrification can displace more than 70% of current fossil fuel use. But full decarbonization will require additional tools. “Hard-to-abate” sectors include long-haul aviation and shipping, which need portable, energy-dense fuels. They also include seasonal energy storage, for which batteries are likely to remain prohibitively expensive. In addition, we’ll need to find substitutes for fossil-fuel-based industrial feedstocks. In all these sectors, hydrogen and its derivatives will play an important role.
Hydrogen is already widely used in fertilizer production, oil refining, and the smelting of iron and aluminum ore. About 120 million tons of hydrogen are produced annually, almost all using fossil fuels. According to the International Energy Agency (IEA), in 2021, hydrogen production was responsible for 830 million tons of CO2 emissions—about 2.2% of the global total.
Decarbonizing hard-to-abate sectors with hydrogen involves the same broad steps as direct electrification. We’ll need to substitute hydrogen for fossil fuel end-uses, replacing, for example, fossil-fuel jet engines with ones that burn hydrogen-derived fuels. We’ll need to build the necessary storage and distribution infrastructure. And, of course, we’ll need to scale up production while reducing emissions.
Two general pathways have been proposed to meet the growing…
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