Peltigera clouds? This fascinating manuscript demonstrates the potential of Peltigera lichens from across a range of ecosystems to generate potent biological ice nucleators. These Peltigera lichen ice nucleators can be more potent than the bacteria Pseudomonas syringae, which is often viewed as the most efficient biological ice nucleators. Given the widespread occurrence of Peltigera across the globe, these lichen may be important contributors to biological ice nucleation.

This paper reveals a previously unrecognized bias in the marine sediment record, challenging conventional interpretations of long-term carbon sequestration and weathering trends. While biases in the fossil and geological records are well-studied, this study demonstrates that deep-sea sedimentation data are also systematically skewed, necessitating a critical reevaluation of widely used paleoceanographic proxies. As a comprehensive meta-analysis of marine core data, these findings have far-reaching implications, highlighting the need to account for age-dependent biases in sedimentation-related proxies to refine our understanding of Earth's past climate and carbon cycle dynamics.

This study presents new insights into autotrophic carbon fixation in shallow-water hydrothermal systems, emphasizing the dominance of reductive tricarboxylic acid (rTCA) cycle-utilizing Campylobacteria. Low isotopic fractionation values in vent fluids, possibly due to very acidic pH levels, extend the isotopic fractionation range of rTCA. The study also highlights the ecological significance of chemosynthetically fixed carbon, observed in higher trophic levels like the vent endemic crab Xenograpsus testudinatus, improving our understanding of carbon cycling in extreme environments and the interplay between microbial chemosynthesis and higher organisms.