Climate Reflections: The SRM360 Podcast

On 9 April 2025, SRM360 hosted a live discussion on the growing debate surrounding moratoria and bans on solar geoengineering. Listen to the episode to explore the differences between bans and moratoria, the pros and cons of each, and policy discussions on the horizon with expert panelists Josh Horton, Julie Vinders, Joe Sonka, and Craig Segall. 

Note, since this recording the U.S. EPA published a new resource on geoenineering.

Why is this relevant now?

• European Commission Review: The Commission is considering proposals for moratoria on certain SRM activities that were recommended by scientific advisors.
• State-Level Bans in the US: More than 25 US states have proposed or adopted a ban on geoengineering.
• Divided academic viewpoints: An influential group of academics have called for a non-use agreement, which includes a ban on outdoor experiments.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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In May 2025, the UK's Advanced Research and Invention Agency (ARIA) announced its initial round of awards for their "Exploring Climate Cooling" programme. The programme will ultimately dedicate £56.8 million to fund sunlight reflection methods research. Some of that funding will go towards field experiments. 

There have been only a few SRM field experiments to date, and some have been cancelled due to public pressure. In this episode, we explore what SRM field experiments have taken place, how they've informed scientific knowledge of SRM, talk with some of the scientists leading those experiments, and explore how outdoor field experiments of SRM should or could be governed. 

This episode features interviews with:

• David Keith, professor of Geophysical Sciences at the University of Chicago and faculty director of the Climate Systems Engineering Initiative (CSEI), an interdisciplinary academic research cluster focused on climate interventions
• John Moore, glaciologist and research professor at University of Lapland in Finland.
• Daniel Harrison, associate professor in the National Marine Science Center at Southern Cross University in Australia and scientific lead for the cooling and shading subprogram of the Reef Restoration and Adaptation Program (RRAP), which includes outdoor marine cloud brightening experiments.
• Jan MacDonald, professor of Environmental and Climate Law at the University of Tasmania in Australia.
• Shuchi Talati, governance expert and executive director of the Alliance for Just Deliberation of Solar Geoengineering.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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Africa is home to many of the world’s least developed nations and its population is rapidly growing, making it one of the most climate vulnerable regions in the world. As such, Africa has much to gain, or lose, from the potential deployment of SRM. SRM360 hosts a live panel discussion at the Degrees 2025 Global Forum in South Africa with leading African experts about the future of Africa, the climate outlook, and the potential and risks of SRM for the continent.

Moderator: Pete Irvine (SRM360.org & University of Chicago)

Panelists:

• Babatunde Abiodun, University of Cape Town, South Africa
• Ernest Ofori, Green Africa Youth Organization, Ghana
• Nana Ama Browne Klutse, Environmental Protection Authority, Ghana
• Portia Adade Williams, Science and Technology Policy Research Institute, Ghana

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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In this episode of Climate Reflections: The SRM360 Podcast, host Dr. Pete Irvine discusses the sunlight reflection method (SRM) known as Marine Cloud Brightening (MCB), which involves spraying sea salt particles below the cloud base to brighten clouds and reflect sunlight. The episode explores two different MCB field experiments by scientists, and discusses the technical, scientific, and ethical challenges of MCB. 

Joining us to explain Marine Cloud Brightening are experts Dr. Isabelle Steinke, Assistant Professor for Climate Engineering at TU Delft, Dr. Michael Diamond, Assistant Professor in Earth, Ocean, and Atmospheric Science at Florida State University, and Dr. Daniel Harrison, Oceanographer and Engineer at the National Marine Science Centre of Southern Cross University and Cooling and Shading Leader for the Reef Restoration and Adaptation Program in Australia.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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To discuss SRM news over the past month, we're joined by Chad Baum, behavioral scientist and Assistant Professor at Aarhus University in Denmark, and Julie Vinders, Lawyer and Senior Research Analyst at Trilateral Research in the UK. We'll talk through the German Environmental Agency's recent policy report on SRM, as well as the Council on Foreign Relations' Climate Realism Initiative, that considers SRM as one of many interventions to "avert catastrophic global climate change". We'll also discuss Julie's article on how the precautionary principle as understood under EU law applies to SRM, and Chad's recent international study of over 30,000 people examining how emotions impact public support for climate interventions. 

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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Modern efforts to clean up air pollution started in the 1950s following the London Smog event, which killed nearly 12,000 people. Much of that pollution was caused by sulphate aerosols. The health and environmental impacts of sulphate pollution were well understood by the 2000s, but another impact was becoming increasingly clear: sulphate aerosols reflected incoming solar radiation, preventing some global warming. The realization that clean air legislation was contributing, in part, to global warming, led Paul Crutzen, a Nobel Prize-winning atmospheric chemist, to make an unorthodox suggestion in 2006: what if we added sulfate particles into the upper atmosphere, purposefully, to reflect sunlight while avoiding negative health impacts? Would it avoid the health impacts? 

This episode explores the history and risks of the sunlight reflection method known as stratospheric aerosol injection (SAI), and its relationship to air pollution. We’re joined by Oliver Morton, Senior and Briefings Editor at The Economist, and Daniele Visioni, Assistant Professor of Earth and Atmospheric Science at Cornell University. 

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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In a contentious meeting in late February, the IPCC agreed on outlines that include discussions of SRM for its 7th assessment report. For the first time in IPCC history, the US was notably absent, having been banned from participation by the Trump administration.  Meanwhile, Raymond Pierrehumbert and Michael Mann, two prominent climate scientists and critics of SRM argue that the UK government should pull the plug on their Advanced Research and Invention Agency - or Aria - which was created by an act of Parliament and intends to commit £56.8 million or about $73 million to projects that evaluate the feasibility, scalability, and safety of solar geoengineering ideas. 

In this monthly news roundup, Pete Irvine discusses these and other recent SRM-relevant developments with experts Sandro Vattioni, Post Doctoral Researcher in Atmospheric Physics at ETH Zurich, Alfonso Fernández, Full Professor of Physical Geography at Universidad de Concepción in Chile, Daniele Visioni, Assistant Professor of Earth and Atmospheric Science at Cornell University, and Tyler Felgenhauer, Senior Research Scientist at Duke University and the Duke Center on Risk.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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Cynthia Scharf has spoken with senior policy makers, UN officials, think tanks and NGOs across the world about climate change and sunlight reflection methods (SRM). Eight years ago, when she first began having these discussions, most people did not see SRM as a serious issue with implications for every country in the world. Now, they are interested. But as interest grows, the gap between the research community and policymakers' knowledge has also grown.

Join our exclusive conversation with Cynthia Scharf, Senior Fellow at the Center for Future Generations, as she shares what policymakers are thinking about SRM and what information needs to be shared to enable transparency in this controversial space.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

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What we'll cover:

• At the end of January, the Arctic Ice Project - formerly Ice 911 - announced they were shutting down. Why? 
• A new study came out this month that draws on focus groups and a survey across 22 countries asking the public who they trust when it comes to information about carbon dioxide removal and SRM. What were the findings?
• A new literature review identifies research gaps across the field of SRM.
• Thoughts on a recent paper about SRM transparency problems.
• A discussion of a recent study focused on how to govern Marine Cloud Brightening
• Famous scientist James Hansen's new piece, and what it means for SRM

To discuss the latest SRM news, Climate Reflections Host Pete Irvine is joined by Viktor Jaakkola, Head of Scientific Collaboration at Operaatio Arktis; Michael Diamond, Assistant Professor of Meteorology and Environmental Science at Florida State University; and Rob Bellamy, Senior Lecturer in Climate and Society at the University of Manchester.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

Follow us to stay updated on the latest episodes:
LinkedIn: SRM360-org
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And subscribe, wherever you get your podcasts!

Climate change will disrupt the geopolitical landscape. So will Sunlight Reflection Methods (SRM). But might SRM help reduce international tensions by reducing the impacts of climate change? Or will these methods cause more or worse disruptions? For this episode of Climate Reflections, host Pete Irvine speaks with geopolitical experts to explore the current geopolitical landscape and how SRM might interact with it to impact international relations.

Guests: Olaf Corry, Professor of Global Security Challenges at the University of Leeds, Beth Chalecki, Associate Professor of International Relations in the Political Science Department at the University of Nebraska, Omaha, and Josh Horton, Senior Program Fellow at the John F. Kennedy School of Government at Harvard University.

Climate Reflections is a production of SRM360, a non-profit knowledge hub supporting an informed, evidence-based discussion of sunlight reflection methods. For more information and the latest research on SRM, visit SRM360.org.

Follow us to stay updated on the latest episodes:
LinkedIn: SRM360-org
Twitter/X: SRM360_org
YouTube: SRM360org
Bluesky: SRM360

And subscribe, wherever you get your podcasts!