Atmospheric hydrogen increased by 70% during the 20th century due to human activity

Analysis of samples from Antarctica showed that the amount of hydrogen in the atmosphere, which was stable in the 19th century, increased significantly in the 20th century. Until now, it has been thought that the main source of hydrogen emissions is automobiles, but experts show that hydrogen emissions do not tend to decrease even when the effects of automobiles are thought to have decreased due to emission regulations. Points out that there are other important factors.

H2 in Antarctic firn air: Atmospheric reconstructions and implications for anthropogenic emissions | PNAS

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John D. Patterson, a geoscientist at the University of California, Irvine, collected an air layer of icecaps in the South Pole and analyzed the amount of hydrogen in the atmosphere. It was found that the amount of hydrogen in the mid-to-late 1800s was 330 ppb, but by 2003 it had increased to 550 ppb.

Hydrogen is expected to be a 'clean energy source' because it can reduce air pollutants by using it in fuel cells, but on the other hand, if it leaks in large quantities, it will extend the life of methane. , It has been pointed out that it leads to a decrease in ozone concentration in the stratosphere.

Until now, it has been thought that the main factor that emits hydrogen into the atmosphere is the automobile. However, in recent years , the amount of hydrogen in the exhaust gas has decreased due to the catalytic converter mounted on the tail pipe of automobiles, and in fact, the concentration of carbon monoxide in the atmosphere tends to decrease due to countermeasures, but hydrogen Emissions are steadily increasing without any signs of decrease.

Other studies have shown a consistent increase in atmospheric hydrogen levels between 2000 and 2015.

From this result, Patterson said, 'We are likely to underestimate hydrogen sources other than automobiles.'

Patterson and colleagues are paying attention to 'hydrogen leaks' from industrial processes. It has not been measured in the past how much 'hydrogen leak' is occurring, but it is estimated that half of the hydrogen emissions from 1985 to 2005 are due to 'hydrogen leak'.

In recent years, 'green hydrogen' that does not generate carbon dioxide in the production process by using renewable energy such as wind power generation and solar power generation when separating water into hydrogen and oxygen has been attracting attention, but in the future, 'green' Patterson and colleagues are concerned that the amount of 'hydrogen leaks' could increase further as 'hydrogen' is produced on a large scale.