New insights into Earth's carbon cycle offer clues for habitability of other planets

Bristol, UK (SPX) Apr 12, 2024
Recent research provides critical new perspectives on the historical evolution of oxygen, carbon, and other essential elements on Earth, potentially aiding in the evaluation of habitability on other planets. The study, published in Nature Geoscience, was spearheaded by University of Bristol scientists who demonstrated the significant role of carbon-rich rocks in boosting oxygen production and release into the atmosphere. This discovery addresses longstanding uncertainties about how Earth's atmosphere became rich in oxygen.

The ongoing emission of carbon dioxide by volcanic activity has long seen carbon transported to oceans, where it forms rocks like limestone. Over time, the accumulation of such rocks facilitates carbon release during tectonic activities, such as mountain formation and metamorphism.

Leveraging this knowledge, the researchers developed an advanced computer model to map critical shifts in the Earth's carbon, nutrient, and oxygen cycles spanning over 4 billion years. According to Dr. Lewis Alcott, lead author and Lecturer in Earth Sciences at the University of Bristol, this study marks a significant advancement in understanding how planets might support complex life forms.

Dr. Alcott highlighted the long-standing mystery surrounding the increase of atmospheric oxygen from trace amounts to modern levels. This complex process has been difficult to model accurately until now, leading to various conflicting theories among scientists.

The study also suggests that older planets, like Earth, which formed billions of years ago, are likely to accumulate sufficient carbon-rich deposits in their crust. This accumulation can enhance the recycling of carbon and nutrients, vital for photosynthesis, thus accelerating oxygen production as Earth's history progresses.

Initiated while Dr. Alcott was a Hutchinson Postdoctoral Fellow at Yale University, this research sets the stage for future investigations into the intricate connections between planetary temperature, oxygen, and nutrients.

Prof. Benjamin Mills, co-author and Professor of Earth System Evolution at the University of Leeds, added that our expanding knowledge of distant stars and their planets might soon predict the chemical potential of these planets. Advances in telescope technology are expected to verify these predictions.

Research Report:Crustal carbonate build-up as a driver for Earth's oxygenation