Should We Cool the Earth?

As the climate crisis intensifies, the conversation has largely centred on how we stop the planet warming: cutting emissions, decarbonising energy and reaching net zero. But what if those efforts are not enough to prevent increasingly dangerous levels of heating? Could we deliberately intervene in the Earth's climate to cool it down?In this Earth Set discussion, the focus is on solar radiation modification (SRM) – a set of proposed techniques designed to reflect more of the sun's energy back into space. The panel explores the science behind geoengineering, from stratospheric aerosol injection to marine cloud brightening, and examines what researchers know, what remains uncertain and how these interventions might affect different parts of the world.Joining the conversation are Oliver Morton, senior editor at The Economist and author of The Planet We Made; Dr Colleen Golja, atmospheric scientist and research fellow at Imperial College London's Grantham Institute; Dr Alistair Duffy, senior scientist at Reflective and visiting researcher at UCL; and Professor Mark Symes, director of ARIA's Exploring Climate Cooling programme.The discussion moves beyond the technical possibilities to confront some difficult questions. Could cooling the planet distract from the urgent need to cut emissions? What happens to rainfall patterns, ocean acidification and the ozone layer? Who gets to decide whether these technologies are researched or ever deployed – and how do we ensure that the countries most vulnerable to climate change have a meaningful voice?At the heart of the conversation is a question that is becoming harder to ignore: if the world continues to warm, should we be researching ways to deliberately cool it – and who should have the power to make that decision?What solar radiation modification is, how it differs from carbon dioxide removal, and why it is attracting growing attention in climate research.How stratospheric aerosol injection could use reflective particles to reduce incoming sunlight, drawing on evidence from major volcanic eruptions.Why marine cloud brightening and sea ice thickening are also being investigated as potential ways to cool or protect vulnerable regions.What the science still cannot tell us about regional rainfall, ocean acidification, ozone depletion and the wider ecological consequences of climate interventions.The ethical and political challenges of governance, including the risks of unilateral action, private-sector influence and unequal impacts between countries.Why building open, publicly shared scientific knowledge now could help governments and communities make better-informed decisions in the future.The Planet We Made – Oliver Morton's book exploring geoengineering and humanity's potential influence on the climate.ARIA – Exploring Climate Cooling – The UK research programme funding projects investigating climate-cooling approaches, their impacts and governance.Reflective – The nonprofit research organisation focused on stratospheric aerosol injection.Alliance for Just Deliberation on Solar Geoengineering – An initiative working on more inclusive governance and discussion of solar geoengineering.The Montreal Protocol – An international agreement discussed as a potential example of effective global cooperation on atmospheric issues.The Earth Set Live brings together founders, investors and policy leaders in London every month to explore the ideas and people shaping a resilient, regenerative economy.Join us on the first Tuesday of every month. Find out more at earthset.co.Please leave us a five-star rating, write a quick review and share the episode with someone interested in climate science, energy or the future of climate policy.Thanks for listening to The Earth Set.In this episode you'll learn:Resources & LinksJoin The Earth Set LiveIf you enjoyed this episode

This episode of the Earth Set podcast is a live recording from our September 2026 event, a conversation with Michael Barnard on the Evidence-Based Energy Transition.We were joined by Canadian energy systems strategist Michael Barnard for an evening's conversation about where the energy transition is actually heading, and where he thinks we are wasting money, time and intellectual effort.Michael’s central provocation was that don’t need nearly as much new technology as we think we do. We need to get much, much better at deploying what already works. What followed was a whistle stop tour round the transition, ranging far and wide:+ Why hydrogen keeps attracting capital despite batteries comprehensively out-deploying it. + Why the UK should concentrate less on inventing new energy technologies and more on grids, storage, heat pumps and removing regulatory barriers. + Why he thinks much of the case for large-scale carbon capture rests on unrealistic assumptions. + Why aviation will ultimately have to confront demand as well as fuel. + Why Canada’s deteriorating relationship with the US may accelerate its economic and energy diversification. + Why he thinks the enormous AI/data-centre build-out is heading for a rather spectacular reckoning.There was plenty to disagree with and people did, testing some of Michael’s assumptions and provoking him back.Huge thanks to Michael for spending the evening with us and for being generous, provocative, funny and extremely willing to be challenged, as well as to everyone who came and joined the conversation.

This week’s bonus episode comes from South by Southwest London, where Earth Set and the Blue Earth Summit hosted a live discussion exploring one of the most overlooked dimensions of the plastics crisis: human health.Guest names:Sian Sutherland - Host, Founder of A Plastic PlanetSaabira Chaudhuri - Author of ConsumedLaura Harnett - Founder, SeepAmir Afshar - Founder, ShellworksProfessor Richard Lea - University of Nottingham The conversation moves beyond familiar debates about litter, recycling and ocean pollution to examine what happens when plastic becomes part of our bodies. From declining fertility and endocrine-disrupting chemicals to the history of single-use plastics and the challenge of building viable alternatives, the discussion brings together scientists, entrepreneurs, campaigners and journalists to ask a difficult question: if the evidence around plastic’s health impacts continues to grow, what will it take for business, policymakers and consumers to respond?Along the way, the panel explores how plastics became embedded in modern life, why recycling is not the answer to solving the crisis, and whether a new generation of materials and business models can reduce our dependence on fossil-fuel-based plastics without creating new problems of their own.In This Episode You'll Learn:• How endocrine-disrupting chemicals found in plastics can interfere with the body’s hormonal systems and reproductive health• Why scientists are increasingly concerned about declining fertility rates, falling sperm counts and rising reproductive disorders• How exposure to certain chemicals during pregnancy may affect health outcomes later in life• The surprising history of how plastics transformed consumer behaviour, packaging and modern convenience• Why plastic production continues to grow despite decades of recycling campaigns and public awareness efforts• What critics argue is wrong with today’s recycling system — and why many believe reduction and reuse must play a larger role• How entrepreneurs are developing alternative materials designed to replicate the benefits of plastic without creating persistent waste• Why regulation, economics and consumer expectations remain major barriers to scaling plastic-free solutions• Whether human health concerns could become the catalyst that finally accelerates action on plastic pollution and chemical safety🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 ⁠earthset.co⁠⁠If you enjoyed this episodePlease take a moment to:• Leave 5 stars• Write a quick review• Share the episode with someone interested in climate technology, innovation or industrial strategyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.

This week’s episode comes from Octopus Energy HQ where Amy Rennison is joined by Phil Cohen, Patrick Matthewson, Rachel Fletcher, and Aruna Ramsamy.The conversation explores a growing tension at the heart of the UK’s industrial strategy: the push to decarbonise heavy industry is running directly into some of the highest industrial electricity prices in the OECD. Across steel, chemicals, manufacturing and energy-intensive production, the technologies for deep decarbonisation increasingly exist — but the economics, infrastructure and policy frameworks are not yet aligned to deploy them at scale.What emerges is not a simple trade-off between climate ambition and industrial survival, but a more complex systems problem: fragmented policy design, high energy system costs, and weak demand signals are all shaping investment decisions in ways that risk slowing both electrification and industrial renewal. Against this backdrop, international examples like Sweden’s H2 Green Steel highlight how low-cost power, coordinated policy and long-term offtake agreements can unlock entirely new industrial ecosystems.The central question becomes whether the UK can correct these structural issues quickly enough to prevent a gradual erosion of its industrial base while still pursuing net zero.In This Episode You'll Learn:• Why UK industrial electricity prices are among the highest in Europe and how policy costs, network investment and market design contribute to them• How energy-intensive sectors like steel, chemicals and glass are already experiencing output declines linked to the energy crisis• Why electrification is widely seen as the main route to industrial decarbonisation, despite technical limits in some high-temperature processes• How fragmented policy between energy, industrial strategy and regulation is slowing investment and creating uncertainty for manufacturers• Why compensation schemes and exemptions only partially offset high costs and fail to address structural competitiveness issues• How projects like H2 Green Steel in Sweden demonstrate the importance of low-cost electricity, carbon pricing and coordinated demand for enabling new industrial investment• Why investors and manufacturers are increasingly calling for deeper market reform, including connection reform, flexibility markets and removal of policy costs from electricity bills🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 earthset.co⁠If you enjoyed this episodePlease take a moment to:• Leave 5 stars• Write a quick review• Share the episode with someone interested in climate technology, innovation or industrial strategyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.

This week’s episode takes a step back from individual topics to look at the bigger picture: a Q1 2026 review of the climate and energy stories that have defined the year so far — and what they mean for what comes next.Hosted by Amy Rennison, the conversation brings together three returning perspectives spanning analysis, politics and capital. Lucy Shaw, energy analyst and advisor, breaks down the system-level dynamics shaping energy markets and infrastructure. Luke Shore, from Project Tempo, explores how these shifts are landing politically, and how voters are responding. And Max Bray, partner at Kindred Capital, offers a view from the investment side, tracking where capital is flowing and where confidence is changing.Across five fast-moving topics, from AI-driven energy demand to US climate policy, capital flows, the Iran crisis, and UK energy strategy, the discussion builds a picture of a system under pressure from multiple directions at once.What emerges is a transition no longer defined by a single narrative. Instead, it’s shaped by competing forces: rapid demand growth, geopolitical instability, political backlash, and uneven progress across technologies and regions.At the centre is a familiar tension, now more visible than ever: the need to move quickly, and the growing risk that rising costs, infrastructure constraints, and political resistance could slow things down.If the transition is no longer just about decarbonisation, but about affordability, security and public consent, the question becomes: can the system adapt fast enough to hold all three together?In this episode you’ll learn:Why AI has rapidly shifted from a tech story to an energy and infrastructure storyHow Europe’s economic fundamentals are affecting its ability to scale climate technologiesWhether we are actually on track for net zero — and how that depends on how you define “on track”Why electrification — not just clean power — is now the critical missing pieceHow the Iran crisis is affecting global energy markets, supply chains and pricingHow high energy prices are affecting UK industry — from steel to ceramicsWhy delivery — not just policy — is now the key challenge for governmentsHow crises like today’s energy shock compare to historical moments like the 1970s oil crisisWhy moments of disruption can either accelerate change — or be missed entirelyResources & LinksProject Tempo – Research on public attitudes to climate and energy policyKindred Capital – Early-stage investment across deep tech and energyCornish Lithium – UK-based lithium extraction and geothermal developmentGridserve – UK EV charging and renewable energy infrastructureFuse Energy – Vertically integrated energy company model🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy. First Tuesday of every month.Grab tickets here:👉 earthset.coIf you enjoyed this episodePlease take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in climate, energy or public policyIt helps more people discover the show. Thanks for listening — see you at the next live event or in your feed soon.

This week’s episode comes from Octopus Energy HQ, where Amy Rennison hosts a live Earth Set conversation on one of the most contested — and least clearly defined — ideas in the transition: the “just transition”.She’s joined by three perspectives spanning community, policy and capital. David Powell from the Local Storytelling Exchange brings a grounded view from communities across the UK, exploring how people actually experience change — often in ways that never show up in policy. Grace Millman, working on just transitions and community energy at Regen, looks at how fairness, participation and regional inequality shape the way net zero lands in real places. And Jordan Fletcher, investor at Future Impact Ventures, shares how capital can be deployed not just to decarbonise, but to create broader social and economic value from the start.The conversation moves beyond theory into the lived reality of the transition: rising energy bills, contested infrastructure, uneven access to new technologies, and the growing sense among many communities that change is happening to them, not with them.Together, they unpack a central tension: the need to move fast — and the risk that moving fast without fairness ultimately slows everything down.If the transition is as much about trust, perception and lived experience as it is about technology, the question becomes this: how do we design a system that people actually feel is working for them?In this episode you’ll learn:Why the “just transition” means different things to different people — and why that ambiguity mattersHow feelings of fairness, pride and dignity shape public support for climate actionWhy most people don’t talk about “climate” — but do care about their homes, bills and communitiesHow storytelling reveals the gap between policy design and lived experienceThe role of trust — and why people are more likely to act on advice from someone they know than from institutionsWhy speed vs fairness is a false trade-off — and how unfair transitions often stalHow infrastructure projects like grid expansion are creating tension in local communitiesWhy energy bills remain the dominant lens through which people experience the transitionResources & LinksLocal Storytelling Exchange – Community-led climate storytelling across the UKCheck out the video mentioned at the start of the episode from the Local Storytelling Exchange that gives the real stories of the green transitionFuture Impact Ventures – Investment in the just transition at the intersection of climate, community and capitalCommunity Energy England – Network supporting local energy projects and ownership models🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 earthset.co⁠If you enjoyed this episodePlease take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in climate, energy or public policyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.

This week’s episode comes from the Eden Project in Cornwall, where Amy Rennison and Fiona Howarth speak to two very different — but equally important — voices in the transition.First, Augusta Grand, CEO of Eden Geothermal, shares the story of bringing geothermal energy to the UK — from early resistance to wind power through to the realities of drilling, financing and scaling a new energy source. The conversation explores why geothermal has long been overlooked, how rapidly the technology is advancing, and why it could play a critical role in both electricity and heat.Then, Amy speaks with Jane Davidson, former Welsh minister and architect of the Wellbeing of Future Generations Act — one of the most ambitious pieces of sustainability legislation in the world. They discuss how the Act came to life, what it has changed, and how it is now shaping Wales’ approach to long-term decision making and net zero.Together, these conversations explore two sides of the same challenge: how we move from ambition to delivery — whether that’s building new energy infrastructure or redesigning the systems that govern it.If the transition depends on both technology and institutions, the real question becomes this: how do we align innovation, policy and people to actually deliver change at scale?In this episode you’ll learn:What geothermal energy is and why it has been underutilised in the UKHow advances in drilling technology are rapidly improving the economics of geothermalThe difference between geothermal for electricity and geothermal for heat — and why heat matters mostWhy countries like France, Germany and the Netherlands are ahead on geothermal deploymentThe role of government policy, funding and market design in unlocking new energy technologiesHow local energy systems, data centres and grid constraints are shaping future infrastructure decisionsWhat the Wellbeing of Future Generations Act is and why it is unique globallyThe shift from a “duty to promote” to a “duty to deliver” in public policyHow long-term thinking is embedded into Welsh governance across all public institutionsReal-world examples of how the Act has influenced procurement, planning and community outcomesWhy political systems struggle with long-term decision making — and how this can changeHow Wales is approaching net zero through a delivery-focused, system-wide planThe importance of making climate policy tangible, practical and accessible to the publicResources & LinksEden Geothermal – Project and research on geothermal energy in the UKWellbeing of Future Generations Act (Wales) – Framework for long-term, sustainable governance.🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 earthset.co⁠If you enjoyed this episode please take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in climate technology, innovation or industrial strategyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.

Behind every climate solution lies a human challenge.A challenge not just of technology or capital, but of people — the skills, training and pathways needed to turn ambition into reality.In this episode, Fiona Howarth sits down with Rich Tyrie, CEO of GoodPeople, to explore the growing green skills gap and what it will take to close it.From building talent pipelines to connecting local communities with meaningful work, Rich shares insights from over a decade of experience working at the intersection of employment, social impact and the energy transition.The conversation explores why millions of workers will need to be reskilled, why the current system struggles to keep up, and why solving the skills gap is as much about coordination and collaboration as it is about education.If the transition to net zero depends on people, the real question becomes this: how do we build a workforce ready to deliver it?Why the UK needs millions of workers to be reskilled for the energy transitionWhat the “green skills gap” actually means — and why it’s bigger than most people thinkHow labour market fragmentation makes it harder to match people with opportunitiesWhy many “green jobs” aren’t obvious — from scaffolders to finance rolesThe difference between “dark green” and “light green” skillsWhy education systems struggle to keep pace with changing workforce demandsThe role of employers in shaping future talent pipelinesHow social value and procurement are influencing business behaviourWhy early engagement with schools and young people is criticalHow place-based approaches can unlock more inclusive access to jobsWhat’s driving collaboration in regions like Greater ManchesterPractical ways individuals can explore and access green careers todayNet Zero Careers – Explore green jobs, training pathways and opportunities across the UK🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 earthset.co⁠Please take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in climate technology, innovation or industrial strategyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.In this episode you’ll learn:Resources & LinksIf you enjoyed this episode

Behind every breakthrough climate technology lies a quieter, more fragile moment. The point where innovation has been proven, but scaling it into the real world becomes uncertain, expensive and deeply complex.In this episode, Amy Rennison sits down with Sarah Macintosh of Cleantech for UK and Jim Totty of Virdis Capital to explore one of the most critical — and least understood — challenges in the climate transition: the “first-of-a-kind” gap, often referred to as the valley of death.Drawing on their recent research with Cleantech for UK, the conversation unpacks why so many promising climate technologies struggle to reach commercial scale, despite strong early innovation and growing global demand.From funding gaps and capability challenges to risk perception and policy design, this episode explores the systemic barriers holding back the next generation of industrial climate solutions — and what it will take to unlock them.If the technologies to decarbonise already exist, the real question becomes this: why are so few of them making it to full-scale deployment?In this episode you’ll learn:What “first-of-a-kind” projects are and why they sit at the hardest stage of climate innovationWhy the transition from pilot to commercial scale is so difficult for climate tech companiesThe funding gap between venture capital and infrastructure finance — and why it persistsHow founders must shift their narrative from “innovative and unique” to “bankable and low-risk”The critical role of offtake agreements, supply contracts and project finance structuresWhy internal capabilities — from leadership teams to technical validation — can make or break scalingHow the UK compares to the US, Europe and Asia in supporting climate technology deploymentThe impact of energy prices and market structures on where projects get builtWhat policy tools (like contracts for difference, procurement and guarantees) can unlock progressWhy ecosystem fragmentation — across investors, corporates, government and service providers — remains a major barrierThe scale of the UK’s pipeline of climate projects and where the biggest opportunities lieWhy this is not just a capital problem, but a systems and coordination challengeResources & LinksCleantech for UK – Research on first-of-a-kind climate projects and scaling challenges🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here: 👉 earthset.co⁠If you enjoyed this episodePlease take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in climate technology, innovation or industrial strategyIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.

Behind every electric car sits a far older and more complex story. A story about minerals, mining, geopolitics and a global race to control the materials that power the energy transition.In this episode, Fiona Howarth sits down with Henry Sanderson, Financial Times journalist and author of Volt Rush, to explore the hidden history of electric vehicles and the critical minerals that make them possible.From the early experiments of Thomas Edison and Henry Ford, to the rise of lithium-ion batteries and China’s dominance of global battery supply chains, Henry unpacks how electric vehicles became viable and why the competition for minerals like lithium, cobalt and nickel is now shaping global politics.The conversation explores how China built its battery industry, why Western countries are scrambling to catch up, and why the clean energy transition still depends heavily on mining, metals and industrial supply chains.If the world is electrifying everything, the real question becomes this: who controls the materials that make electrification possible?In this episode you’ll learn:The surprising early history of electric cars and why they nearly won the race against gasoline vehicles over a century agoHow lithium-ion batteries unlocked the modern EV revolutionWhy minerals like lithium, cobalt, nickel and graphite are essential to the clean energy transitionHow China built dominance across the global battery supply chainWhy Western countries struggle to finance new mining projectsHow geopolitics, trade policy and subsidies are reshaping the EV industryThe tension between sustainable mining and the massive demand for critical mineralsWhat the next generation of battery technology and energy storage could look likeResources & LinksHenry Sanderson – Volt Rush: The Winners and Losers in the Race to Go Green🎟️ Join Earth Set LiveWe host monthly live events in London featuring founders, investors and policy leaders shaping the transition to a resilient, regenerative economy.First Tuesday of every month.Grab tickets here:👉 earthset.coIf you enjoyed this episodePlease take a moment to:Leave 5 starsWrite a quick reviewShare the episode with someone interested in clean energy, geopolitics or the future of electric vehiclesIt helps more people discover the show.Thanks for listening — see you at the next live event or in your feed soon.