Hydrogen isn’t as clean as it seems

The need to end fossil fuel reliance, and do so in the next decade or two, cannot be overstated. Pressure from society to act has risen to the level where even the fossil fuel industry itself feels compelled to endorse transition plans that at least appear to be legitimate solutions to our deepening climate crisis. Unfortunately, some of these plans are grossly misguided, with “blue hydrogen” being a particularly egregious example. Blue hydrogen is made from fossil natural gas, with carbon capture theoretically used to reduce some greenhouse gas (GHG) emissions from the process. So far it is largely just a concept, and only two facilities in the world have ever tried to produce blue hydrogen at commercial scale.

“Green” hydrogen, made from renewable electricity, seems likely to play an important role in a decarbonized future. Today, though, the vast majority of hydrogen, 95 percent, is produced from fossil fuels, mostly from fossil natural gas, and almost all of this without any effort to capture carbon. Industry calls this dirty hydrogen “grey hydrogen.” Natural gas is composed mostly of methane, and the methane in natural gas is the feedstock used to produce the grey hydrogen, converting methane to hydrogen plus carbon dioxide under high temperatures and pressures. Energy is needed to generate this heat and pressure. Natural gas is almost always used to supply this energy, since it is already being used as the feedstock. Overall, emissions of both carbon dioxide and unburned methane are 50 percent greater for grey hydrogen than simply burning natural gas for the same quantity of energy. The GHG footprint of fossil fuel-produced hydrogen is substantially larger than even that of coal.

Increasingly in recent years, the natural gas industry has started to promote the idea of blue hydrogen. At first glance it sounds promising, but do not be fooled: Blue is not the new green. The emissions from blue hydrogen are still staggeringly high. Combined total GHG emissions are still more than those from using either coal or natural gas directly for energy. And emissions of leaked methane are rife throughout the process. Pound-for-pound, methane is 86 times more powerful a GHG than is carbon dioxide over 20 years, and 25 percent of the global warming experienced by the Earth in recent decades has been driven by methane. A recent report from the United Nations Environmental Programme highlighted these facts, and called for reducing methane emissions as one of the easiest avenues open for slowing the rate of climate change. Blue hydrogen moves us in the wrong direction, increasing methane emissions.

There are also serious questions about what happens with the carbon dioxide that is captured. The goal of finding permanent, leak-proof geological storage sites has proved elusive. Today, almost all carbon capture is from oil and gas processing facilities and the carbon dioxide is not permanently stored at all: Rather, the vast majority of captured carbon dioxide is used for enhanced oil recovery. The gas is simply pumped into oil wells to stimulate production. The irony of using climate-damaging byproducts from fossil fuel production in order to extract even more fossil fuels from the ground cannot be ignored.

President Biden’s Environmental Justice Advisory Council recently urged the administration to avoid investments in carbon capture and storage technology, citing the localized environmental and public health burden these processes inflict on nearby communities. Despite this recommendation from his own administration, Biden put forward a budget that would provide $9 billion in subsidies that could be used to promote and develop blue hydrogen, and Department of Energy Secretary Jennifer Granholm launched the Hydrogen Energy Earthshot, a program that will seek to find ways of making blue hydrogen cheaper to produce. Meanwhile, a last-minute addition to Sen. Ron Wyden’s (D-Ore.) Clean Energy for America Act, which seeks to eliminate $15 billion in fossil fuel subsidies, included a new subsidy for blue hydrogen. This giveaway would not only harm environmental justice communities, but directly conflict with Biden’s pledge to eliminate fossil fuel subsidies as part of a broader plan to address climate chaos. 

Hydrogen may be useful in our clean energy future, particularly to store excess renewable electricity, producing hydrogen by electrolysis and feeding it to fuel cells to again produce electricity when needed. Truly clean hydrogen may also play a role in our transportation systems, especially for long-range heavy and ground transport. How much hydrogen, and where and how we produce and use it are important questions that need to be addressed. But it is already clear that producing hydrogen from fossil gas is not clean, with or without successful carbon capture, and half-baked schemes like “blue hydrogen” should be rejected out of hand.

Robert Howarth is professor of Ecology & Environmental Biology at Cornell University and a board member of the national advocacy group Food and Water Watch.