Perspectives

This issue’s theme is on the importance of large igneous provinces (LIPs) driving global environmental change. As discussed in this issue’s articles, these massive but short-lived magmatic events profoundly impacted the evolution of life through mass extinctions and, in some cases, changing the long-term climatic state of our planet. LIPs are a reminder that the whole Earth, from the core to the crust to the atmosphere, ocean, and life are interconnected, but more specifically, the dynamics of the Earth’s interior plays a key role in facilitating life. For life to exist, disequilibrium must exist. Disequilibrium gives rise to energy gradients. At the most basic level, life can be seen as merely a means of facilitating the flow of energy across these gradients. For example, life-sustaining energy can be accessed from redox potentials between reduced volcanic gases and the oceans and atmosphere. Temperature gradients in hydrothermal environments also provide life-giving energy. But for most of Earth’s history, the most important source of life-giving energy comes from the Sun, accessed through the biochemical reactions associated with photosynthetic organisms. From photosynthesis, the Sun’s energy is captured and stored in the form of reduced carbon, which is then distributed across the planet to sustain non-photosynthetic life, even in places where the Sun does not shine, e.g., the deep sea or in soils.