Scientists have discovered that methane in the open ocean is produced by microbes under nutrient-poor conditions, solving a long-standing mystery. As warming oceans reduce nutrient mixing, these methane-producing microbes may thrive. This could lead to increased methane emissions from the sea. The result is a potential feedback loop that could intensify climate change.

link to open access article…

https://www.pnas.org/doi/10.1073/pnas.2521235123

Figure 4:

Oxic CH4 production distribution and budget. (A) Oxic CH4 production rate as a function of [PO4]. The black line is our model-derived parameterization when optimized with 100% of the data, while the gray lines are optimized with random samples of 80% of the data. Red and green dots are measurements from seawater incubations (7) and single-species cultures (16), plotted as % inhibition of CH4 production relative to rates when PO4 is absent (right y-axis). The blue arrow shows the PO4 threshold for C-P lyase activity in a bacterial monoculture (35). (B) Depth-integrated oxic CH4 production rate, from optimization using 100% of the data. © Basin-integrated rates of oxic CH4 production and sea-air exchange. Bar centers from optimization using 100% of data, error bars are 1 SD from the optimizations using 80% of the data.