Researchers see 70% increase in atmospheric hydrogen over the past 150 years

UCI Earth System scientists studied the air trapped in compacted layers of Antarctic ice and snow to find answers and some new questions about the amount of molecular hydrogen in our planet’s atmosphere. H₂ is a by-product of the combustion of fossil fuels, the combustion of biomass and the oxidation of methane, among other sources, and has an impact on global warming and the ozone layer. UCI researchers, who were joined by scientists from the National Oceanic and Atmospheric Administration, University of Colorado Boulder and UC San Diego, have learned that molecular hydrogen has dropped from 330 to 550 parts per billion in Earth’s atmosphere from 1852 to 2003, the time period measured in snowflake air collected near the South Pole in Megadunes, Antarctica. The team reported on their findings in a recent article published in the Proceedings of the National Academy of Sciences.

“Aging air is trapped in the perennial snowpack above an ice cap, and its sampling gives us a very accurate account of atmospheric composition over time,” said lead author John Patterson, graduate student from the laboratory of Eric Saltzman, professor of the Earth at the UCI. system science. “Our paleoatmospheric reconstruction of H₂ levels has dramatically improved our understanding of anthropogenic emissions since the start of the Industrial Revolution. “

Patterson said that most of the growth in H₂ is attributable to human activities, particularly those resulting in emissions from transportation, but part of the increase is still not accounted for. “Government policies on tailpipe emissions have led to a decrease in carbon monoxide in the atmosphere, so we should have expected the same impact on molecular hydrogen, but this does not appear to be the case,” he said. he declared. “There is no evidence that molecular hydrogen emissions to the atmosphere have decreased in the 20th century, so we are probably underestimating non-automotive gas sources.”

Researchers said there may be a new source of H₂ emissions are on the horizon as more people switch to zero-carbon hydrogen for automobiles and other needs, leading to the possibility of leaks into the atmosphere.