Hidden Hydrogen Pollution Is Worsening Global Warming, Major Study Finds

Scientists study how hidden hydrogen pollution is quietly warming the planet. A new research shows hydrogen leaks extend methane's life, amplifying its warming effect. Learn why this unseen threat could challenge the future of clean hydrogen energy.

When discussing climate change, people often focus about carbon dioxide and methane. However, recent studies reveal that hydrogen has also been quietly contributing to global warming and making the problem even worse. A major international study published in Nature has found that increasing hydrogen emissions over the past 30 years have slightly raised Earth's temperature and, more importantly, intensified the harmful effects of methane.

This research, conducted by the Global Carbon Project, a group of scientists from around the world, was the first to properly track the sources and destinations of hydrogen in the atmosphere.

Hydrogen: The Smallest Molecule in Existence

Due to its small size, it leaks easily from pipes, factories, and storage tanks. At first glance, hydrogen might seem like a minor issue. Unlike carbon dioxide or methane, it does not trap heat directly. However, once it enters the atmosphere, it interacts with other gases, which can increase warming.

The biggest impact of hydrogen comes from its effect on methane, one of the most powerful greenhouse gases. Normally, methane is broken down by natural “clean-up” chemicals in the air, sometimes referred to as the atmosphere’s detergents.

Hydrogen consumes these detergents. As hydrogen levels in the air increase, there are fewer detergents left to break down methane. This means methane remains in the atmosphere longer and continues to trap heat.

“More hydrogen means fewer detergents in the atmosphere, causing methane to persist longer and, therefore, warm the climate longer,” explained one of the lead authors Dr Zutao Ouyang.

In this way, hydrogen indirectly warms the planet about 11 times faster than carbon dioxide over 100 years and about 37 times faster over 20 years.

Increased Warming Through Chemical Reactions

These reactions can lead to the formation of ozone and water vapour in the upper atmosphere, both of which trap heat. It may also influence cloud formation. The researchers discovered that hydrogen levels in the atmosphere rose by about 70 percent from pre-industrial times to the early 2000s. After a brief pause, levels began to rise again around 2010. Between 1990 and 2020, most of this increase came from human activities.

One Major Source Is Methane Itself

As methane breaks down in the air, it turns into hydrogen. Since methane emissions from fossil fuels, agriculture, and landfills have been increasing rapidly, so have hydrogen emissions. This creates a damaging feedback loop: more methane leads to more hydrogen, and more hydrogen helps methane stay in the atmosphere longer.

“The biggest driver of hydrogen increase in the atmosphere is the oxidation of increasing atmospheric methane,” said Professor Rob Jackson of Stanford University, who led the research

Since 1990, hydrogen created this way has grown to about 27 million tonnes a year.

Other sources include leaks from industrial hydrogen production and farming practices, such as the use of nitrogen fertilizers for growing crops like soybeans. Natural sources, such as wildfires, vary year to year but show no clear long-term trend.

Why Is This Study Important

The study also examined how hydrogen is removed from the atmosphere. Around 70 percent is absorbed by soil, where bacteria use it as an energy source. Overall, the extra hydrogen in the atmosphere has raised global temperatures by about 0.02°C. That may seem small, but it is similar to the total warming caused by all the emissions of a large industrial country like France.

These findings raise concerns about the use of hydrogen as a clean alternative to fossil fuels. Currently, over 90 percent of hydrogen is produced using coal or natural gas, which releases large amounts of carbon dioxide.

In theory, hydrogen can be made using renewable energy with very low emissions, and many climate plans rely on this happening in the future. However, the researchers warn that hydrogen leaks could reduce these climate benefits. Professor Jackson says we need a much better understanding of hydrogen's role in the climate system, so we can build a hydrogen economy that is truly safe for the climate.