Tim Lenton gave an enthralling final talk of the events, one which focused on the historical development and continued resonance of the Gaia theory and Earth System Science. Tim moved between biographical and autobiographical content - a detailed background to James Lovelock, originator of the Gaia theory, as well as reflection on Tim's own subsequent Gaia-inspired contributions to the field  - historical background to Earth System Science, elaboration of scientific ideas, and philosophical reflection on humanity's future on the Earth. The talk began with an introduction to Lovelock and the development of his scientific thinking in the postwar era. We learnt that the Gaia theory was well in development by the time the Blue Marble photograph was taken. Tim presented a striking range of primary documents that detailed Lovelock's work in the 1960s and 1970s, including research he undertook while at NASA, prophetic warnings in the 60s of human-instigated environmental catastrophe, and correspondences with scientist and collaborator on the Gaia theory Lynn Margulis. The talk then covered Gaia's impact on the development of Earth System Science, where Tim reflected on his own work and career. Importantly, and as Tim's collaborations with the philosopher Bruno Latour have emphasised, the talk encouraged us to view Gaia from "within" as well as "above." In other words, the theory might be known for its "top down" view of the Earth as a singular, interconnected, self-regulating system (and so often visualised by way of the Blue Marble and similar imagery). But Gaia can also be thought about from the bottom up, in relation to individual humans and all of our potential to "self regulate" and contribute to our planet's future.  In the "Further Resources" section, you can find links to more of Tim's writing, including his influential book Revolutions That Made the Earth.