At a Glance
- Methane, a potent greenhouse gas, forms methane hydrate (an ice-like solid) under low temperatures and high pressure, storing vast amounts of carbon beneath the seafloor.
- Methane hydrate deposits contain at least 1,800 gigatons of carbon, with some estimates suggesting it could exceed 20,000 gigatons. This is compared to 475 gigatons of carbon dioxide emissions from fossil fuels since the Industrial Revolution.
- Rising temperatures can destabilize methane hydrates, releasing methane gas, which could further exacerbate the greenhouse effect and contribute to climate change.
- Researchers are studying past warm periods and methane hydrate stability using advanced technologies like dual-clumped isotope thermometry to understand the impact of temperature changes on methane release.
- Microorganisms in ocean sediments consume methane and convert it into carbonate minerals. Studying the isotopic composition of these carbonates provides insights into past ocean temperatures, microbial activity, and methane dynamics.
Methane, a potent greenhouse gas, is approximately 25 times more effective at trapping heat than carbon dioxide. When methane combines with water at low temperatures and high pressure, it forms methane hydrate, an ice-like solid found in vast deposits beneath the seafloor. These deposits store an immense amount of carbon, estimated to be at least 1,800 gigatons, with some projections suggesting it could exceed 20,000 gigatons. In comparison, since the Industrial Revolution, human carbon dioxide emissions from fossil fuels amount to 475 gigatons.
Methane hydrate is sensitive to temperature changes; if temperatures rise, it can break down into methane gas and water, leading to methane seeps, where the gas escapes from the sediment. Scientists are concerned that climate change could trigger increased methane release from these deposits, further exacerbating the greenhouse effect. Understanding the potential risks of methane hydrate destabilization is crucial for climate research.
Researchers, including Jens Fiebig from the University of Hamburg, are investigating the historical context of methane hydrate stability to assess the current situation. By studying past warm periods and the behavior of methane hydrate deposits, they aim to determine the impact of temperature changes on methane outgassing. Recent technological advancements, such as dual-clumped isotope thermometry, offer new insights into reconstructing past ocean temperatures and microbial interactions related to methane flux.
Microorganisms are vital in consuming methane released from deposits, using it as an energy source. These microbes reside in ocean sediments covering methane hydrate deposits and convert the gas into carbonate minerals. Dual-clumped isotope thermometry helps researchers analyze the isotopic composition of these carbonates, providing valuable information on temperature conditions during mineral formation and the influence of microbial activity. This innovative approach enhances our understanding of methane dynamics in marine environments and offers potential applications in studying past climate changes and their effects on methane release.
For further reading, the original study was published in Science Advances.
References
- Bernards, M. & Goethe University Frankfurt am Main. (2024, June 3). Measuring temperature of seafloor millions of years ago may show if ocean warming increases methane release. Phys.Org; Goethe University Frankfurt am Main. https://phys.org/news/2024-06-temperature-seafloor-millions-years-ocean.html
- Staudigel, P., Feng, D., Peckmann, J., Bernecker, M., Davies, A., Tagliavento, M., & Fiebig, J. (2024). Resolving and correcting for kinetic biases on methane seep paleotemperature using carbonate ∆47/∆48 analysis. Science Advances, 10(22), eadn0155. https://doi.org/10.1126/sciadv.adn0155
