Erica Gies is a California-born environmental journalist who has spent more than a decade reporting on water from every angle — drought, flood, irrigation, hydropower, urban infrastructure, indigenous stewardship — and whose first book, Water Always Wins: Thriving in an Age of Drought and Deluge (University of Chicago Press, 2022), brought together stories of communities on every continent rebuilding their relationship with water rather than fighting it. She is now writing her second book, Roots to Sky: How Life and Water Can Help Cool Earth’s Climate, which goes further into the atmosphere to explore how the water–land–climate nexus connects land restoration, water vapour, and the cooling of a heating planet. It is due in 2028.

The common climate narrative — decarbonise, bring fossil fuel emissions to zero, problem solved — is no longer sufficient on its own. Water vapour accounts for roughly half of the greenhouse effect, and 75% of the land on earth has already been degraded, much of it by draining it. Record-breaking summer heat across the northern hemisphere in 2026 cannot be explained by CO2 alone; land use change is a major driver. The good news, which Erica explores in both her TEDx Boston talk and her forthcoming book, is that this is something we can change relatively quickly through land restoration — and that water is absolutely the key lever.

In this conversation — recorded in July 2026, part of the podcast’s ongoing Water Cycle series — we get into why Erica shifted from below-ground water management to the atmosphere, why a 1970 MIT Press report already knew that pumping groundwater raises sea levels and we have only accelerated since, what beavers in California are teaching conservative farmers who spent eighty years shooting them, why investors who optimise single variables are going to run out of natural buffers faster than they think, why land back for indigenous peoples is one of the highest-return interventions available, and why Erica’s magic wand answer — caring for non-humans — is less idealistic than it sounds.