The Powerful Impact of Microbial Methane Emissions on Global Warming

Tuesday - August 8 2023, 06:29 UTC - 1 year ago

A recent study published in Geology revealed evidence of increased sea surface temperature, continental ice decline, and oceanic environments flooding the land from a pivotal era 304 million years ago during the Late Paleozoic Ice Age. The findings suggest that microbial methane emissions during this era may have reached a staggering 2.1 gigatons, and were connected to the rise in atmospheric methane. The collective impact of alkaline lakes globally could have significantly influenced greenhouse gas levels, potentially equaling up to 7521 gigatons of carbon dioxide. These findings underscore the influential role of methane in shaping our climate.

Our planet has a long history of global warming, spanning millions of years, as evidenced by a recent study published in Geology, which delves into a pivotal era 304 million years ago during the Late Paleozoic Ice Age. The findings reveal evidence of increased sea surface temperature, continental ice decline, and oceanic environments flooding the land.

Dr. Liuwen Xia and a team of researchers from Nanjing University, China, embarked on a quest to uncover the secrets of an ancient warming episode. To unravel the mystery, the team investigated the impact of methane emissions from alkaline lakes with pH levels ranging from 9 to 12. Methane, a potent greenhouse gas, can trap heat in the atmosphere 28 times more effectively than carbon dioxide over a century. The microorganisms responsible for methane production contribute to a substantial portion of global methane emissions, – accounting for 74 percent. Understanding the conditions that enable these microorganisms to thrive is crucial for comprehending climate change dynamics.

The researchers focused on the Junggar Basin in northwest China, where they meticulously examined methane levels derived from microbial activity. Core samples from the lake bed were subjected to rigorous chemical analyses, providing insights into carbon sources, including aquatic green algae, photosynthesizing cyanobacteria, and extremophilic halophilic archaea that inhabit high salt environments. A crucial revelation emerged from their investigations: a specific type of microorganism, alkalophilic methanogenic archaea, thrived in the lake’s low sulfate anoxic conditions. This microorganism harnesses energy from methane production, releasing it into the atmosphere. The findings suggest that microbial methane emissions during this era may have reached a staggering 2.1 gigatons.

The researchers connected this surge in methane emissions to the Late Paleozoic Ice Age, marked by a peak in atmospheric methane 304 million years ago. They propose that the collective impact of alkaline lakes globally could have significantly influenced greenhouse gas levels. In the context of northwest China alone, methane emissions could have surpassed 109 gigatonnes, equivalent to the potential greenhouse impact of up to 7521 gigatons of carbon dioxide.

The implications of these findings are profound, underscoring the influential role of methane in shaping our climate. Potential solutions include altering lake pH, introducing specific clays, or even modifying lakebeds. However, each solution introduces its own set of environmental repercussions. Additionally, identifying alkaline lakes worldwide will present its own challenges. The complete study was published in Geology.

The evidence collected may help us to understand worldwide climate change dynamics and potential solutions. The implications of these findings are far-reaching, underscoring the powerful influence of methane emissions on global warming.