1. Ancient Microbes Caused Earth's First Global Warming

    Artist's concept of an ice-covered planet in a distant solar system, resembling what early Earth may have looked like it the right mix of microbial metabolisms and volcanic processes hadn’t warmed the climate. Source: European southern observatory (EXO) via Wikimedia Commons Image credit: None
    Artist's concept of an ice-covered planet in a distant solar system, resembling what early Earth may have looked like it the right mix of microbial metabolisms and volcanic processes hadn’t warmed the climate. Source: European southern observatory (EXO) via Wikimedia Commons

    Kazumi Ozaki, a NASA Postdoctoral Program Fellow at Georgia Tech, with the NASA Astrobiology Institute (NAI) Alternative Earths team and Chris Reinhard, a member the NASA Astrobiology Institute team at Georgia Tech, have designed an innovative model linking microbial ecosystems, volcanism, photochemistry, and atmospheric escape to enable rapid analysis of probabilities of different climate states.Their work reveals the importance of early photosynthetic life for warming Earth-like planets around dim stars.

    Their results call for a reevaluation of the factors regulating climate and habitability on both the early Earth and other anoxic Earth-like worlds. They also highlight the importance of networked interactions between microbial metabolisms for controlling atmospheric chemistry and climate, and the usefulness of early Earth as a ’natural lab’ for Earth-like exoplanets.

    “We think this represents a wonderful example of what understanding the early Earth brings to the broader issue of planetary habitability and atmospheric signs of life,” says Reinhard.

    The paper, “Effects of primitive photosynthesis on Earth’s early climate system,” is published in Nature Geosciences.

    A press release is also available at New Scientist.

    Source: [Nature Geosciences (via UCR and Georgia Tech)]