Hydrogen is recognized as a critical component of the world economy’s decarbonization. Green H2, which is generated from renewable energy sources, may be used to replace “conventional” CO2-emitting fuels in a variety of applications.
Is hydrogen environmentally friendly? Two recent British studies suggest that releasing huge amounts of hydrogen into the atmosphere can contribute to global warming (indirectly) to some extent.
The reality is that hydrogen may react with other gases and vapors, resulting in climate change. “Any hydrogen leak will change the composition of the atmosphere (with consequences for air quality) and cause indirect global warming.”
It’s worth noting that hydrogen helps to extend the “lifetime” of atmospheric methane, which is a potent greenhouse gas that, unlike “long-lived” CO2, only lasts around 20 years in the atmosphere. Hydrogen combines with the same tropospheric oxidizers that “clean” the atmosphere of methane, lowering the number of free hydroxyl radicals, which function as scavenging agents. As a result, the concentration of methane rises, and it remains in the atmosphere for longer.
Furthermore, the presence of hydrogen elevates tropospheric ozone and stratospheric water vapor concentrations, amplifying the “radiative forcing” action that also raises the temperature.
The authors of the “Atmospheric Implications of Increased Hydrogen Use” research found that the “Global Warming Potential” H2 (English Global Warming Potential or GWP) is equal to 11 with an error of ± 5, that is, it is in the range from 6 to 16. This suggests that a ton of hydrogen in the atmosphere will heat the Earth 11 times more (with the given uncertainty) during a 100-year period than a ton of CO2.
Scientists estimate that one to ten percent of all hydrogen will “leak” into the atmosphere, with certain climatic consequences.
It’s worth noting that the assumptions that this study is founded on don’t appear to be particularly practical. As a result, the authors predict that the real estate sector will transition to hydrogen entirely. This will obviously not happen, even if one ignores the fact that H2 is unsuitable for use in building heating. A shift to hydrogen for 50% of all transportation is also a paradise.
Another research, Fugitive Hydrogen Emissions in a Future Hydrogen Economy, claims that present hydrogen technologies can result in “quite considerable emissions” (leaks) of H2, but that “very simple processes” can be used to limit them.
According to the primary scenario in this paper, between 1 and 1.5 percent of all hydrogen in the globe will “leak” into the atmosphere, with half of the leaks originating from transportation.
Of course, none of this implies that the usage of green H2 should be discontinued. According to the scientists, the rise in CO2 equivalent greenhouse gas emissions from 1% and 10% H2 leakage balances only about 0.4 percent and 4% of the CO2 emission reductions owing to the switch to green hydrogen, respectively.
As a result, the harmful impacts of hydrogen leaks on the environment are limited, but leaks must be controlled and reduced.
