Data centers, El Niño coral records, and the Swift telescope: Inside Science explores climate, oceans and space

What this episode covers

In this edition of Inside Science, the team dives into three major threads: the growing demand for data centers and how their water cooling and energy needs affect water resources and decarbonisation, the coral-based reconstruction of past El Niño events and what that tells us about future climate, and the fate of NASA's Swift gamma ray burst telescope and what its end-of-life means for high-energy astrophysics. Along the way, listeners meet Deborah Andrews and Julie Cole, and hear from Rose George about the hidden lives of fishes and the human stories behind fishing. The show also showcases how science travels from the field to the lab, and how researchers balance competing pressures from technology, environment, and policy.

• Data centers as a growing energy and water demand, and trade-offs between water cooling and energy efficiency
• Coral-derived El Niño records and what they reveal about climate variability over the last thousand years
• The Swift telescope’s remarkable longevity and the challenges of saving space missions
• Fisheries, fish sentience, and the human side of fishing communities

Introduction and episode focus

The episode opens with an overview of three intertwined topics: the rapid rise of data centers and how their cooling and power needs intersect with water resources and decarbonisation goals; the climate and ocean science that uses coral records to reconstruct historical El Niño variability; and the fate of the Swift gamma ray burst telescope, including a recent attempt to rescue it and what its loss means for our understanding of high-energy astrophysics. The program emphasizes that data, climate, and space science are part of a single spectrum of modern science, each with its own challenges and implications for policy, infrastructure, and our daily lives.

Data centers, water use and energy demands

Deborah Andrews, an Emeritus professor at London South Bank University, explains why data centers have become a focal point now. She notes that while data centers have existed for decades, there is exponential growth driven by AI and the demand for digital services. The discussion centers on three main water-related uses in data centers: cooling the compute equipment, supporting electricity generation for compute services, and the embodied water in components and materials. Andrews stresses that estimates of water use depend on scope, and that cooling can be done with air or with liquids, with evaporative cooling being common but water-intensive. Closed loop systems exist, but they require effective heat dissipation or reuse of heat energy to avoid simply dumping heat as a waste product.

The conversation then moves to energy use. If data center expansion continues as planned, energy demand could rise significantly, potentially increasing current totals of around 2 to 2.5 percent of national electricity use. The potential fourfold increase by 2030 raises questions about carbon emissions and grid impacts. The podcast also considers whether AI could help manage electricity demand and reduce consumption, but notes that the scale of AI's energy footprint may offset some efficiency gains. The discussion touches geopolitical considerations about optimal siting of data centers, the balance between proximity to end users and access to cheap green electricity, and the security implications of relying on overseas infrastructure.

End-of-life and design for repair in data centers

Deborah outlines how end-of-life data center equipment presents design challenges and opportunities. The episode emphasizes the shift toward serviceability, repair, and upgrading, with a view to easier disassembly and recycling of components. The idea is to move away from “first life” design and toward a circular economy where materials can be recovered and reused, reducing environmental impact even as technology evolves. The segment raises questions about how willing the industry is to embrace changes that facilitate repair and recycling, and whether these changes can keep pace with rapidly advancing computing technology.

El Niño, corals and the climate record

Roland Pease introduces Julie Cole, a paleoclimatologist at the University of Michigan, who discusses the double whammy of climate change and El Niño. The team explains how corals on Pacific islands can provide monthly-resolution climate records back through centuries, enabling researchers to compare modern El Niño with historical extremes. Coral skeletons record temperature through chemical signatures, allowing scientists to reconstruct past events even when long instrumental records are incomplete. The Galapagos becomes a critical locus for study because its location makes El Niño events particularly impactful there, and the corals can reveal the amplitude and variability of El Niño across time.

Coles explains that the data show a broader variability in recent centuries, with modern El Niño events appearing to be stronger than preindustrial counterparts. The discussion highlights that the 1997–1998 event is well-documented, while the infamous 1877–1878 event is not consistently seen as a Super El Niño in Galapagos coral records. This underscores the importance of cross-checking coral records with other tropical Pacific observations to accurately characterize the event’s strength. The researchers also consider how climate change could modify the spatial patterns of rainfall and drought, potentially spreading the climate impacts of El Niño to new regions.

What the future holds for El Niño and climate patterns

The scientists discuss how El Niño might intensify in a warming world, and how that could lead to a broader web of climate impacts beyond typical subtropical and tropical patterns. The coral records suggest that as global temperatures rise, variability may increase, potentially shifting risk toward higher-latitude regions and complicating the global climate response. The segment emphasizes the need to combine historical coral data with other paleoclimate proxies to produce a robust picture of past and future El Niño behavior. The broader implication is that as the climate warms, the interaction of global warming with natural climate cycles could lead to more complex and severe weather extremes.

Swift telescope’s arc and end of life in space

Caroline Steele guides listeners through the Swift gamma ray burst telescope saga. Launched in 2004, Swift is renowned for its rapid reaction capability, enabling it to pivot toward explosions within roughly a minute, a speed that outpaces older observatories like Hubble in some aspects. The program notes that atmospheric drag will gradually pull Swift into a demise as it descends toward Earth. NASA allocated funds to Catalyst, a private firm, to design a spacecraft (Link) to capture and hurl Swift into a safe orbit, but the mission ultimately could not proceed after Link lost its fuel. This marks the end of Swift’s operational life, a poignant reminder of how space missions can exceed expectations far beyond their original lifespans.

The discussion compares Swift to other venerable space instruments such as Hubble and the Mars rovers, which demonstrate surprising longevity. The panel reflects on NASA’s capability to build lasting machines and ponders whether the public relations aspect of mission lifecycles sometimes masks the real engineering triumphs behind sustained operations in harsh environments. The segment closes with a reflection on the value of long-running, nimble instruments in advancing high-energy astrophysics and the inevitability of mission retirement as technology evolves.

Fishes, ethics and the human stories behind the sea

Rose George discusses her book on fishes and the moral dimensions of fishing. The conversation centers on using the plural “fishes” to remind readers that fishes are animals with sentience, capable of feeling and cognition. The narrative weaves together the ecological crisis facing the oceans with human stories from the Scottish coast. George explains how 90% of fish stocks are in trouble and how the global economy obscures declines in local populations. She discusses line catching versus more destructive methods, and highlights how consumer choices—such as sustainably certified seafood—only go so far when the overall picture remains dire.

The book explores debates about the ethics of fishing and the cognitive lives of fish, drawing on research that suggests fish feel pain and may possess complex behaviors. The author shares experiences diving, meeting fishermen like Rex and Captain Tom McClure, and examining the human dimension of industrial fishing. The interview also touches on the moral dimensions of making difficult choices about livelihoods, nets, bycatch, and the cultural significance of the sea. The segment ends with reflections on the value of empathy for fish as sentient beings and the broader ecological consequences of overfishing.

Science in the podcast: a mosaic of inquiry

In the closing sections, the presenters highlight how science travels from fieldwork to lab analysis, from coral cores to space instruments, and how interdisciplinary collaboration shapes our understanding of data centers, climate, oceans, and space. The show demonstrates how new data streams—from coral cores to AI-driven energy management—help scientists probe questions that matter for society, from carbon footprints to weather extremes and the long-term viability of space assets. The final reflections celebrate curiosity, the diversity of scientific topics, and the ongoing pursuit of understanding in a rapidly changing world.