Guest Speakers

and Presentations

HPAC regularly hosts presentations by their participants and other leading experts on a variety of global climate issues.  Recordings, links to the presentation slides, and references, for these sessions are available below.  

Guest Speaker Recordings, Slides & References

Peter Ward, Professor of Biology, Professor of Earth and Space Sciences, University of  Washington

Recording: Our Flooded Earth: Not if, but when. March 7, 2024

Slides: Our Flooded Earth: Not if, but when

Dennis Garrity, Chair of the Board, Global EverGreening Alliance

Recording: Direct Climate Cooling Advocacy Feb. 22, 2024

Dr. Katherine Romanak, Research Professor at the Bureau of Economic Geology, Jackson School of Geosciences, UT Austin. 

Recording: Carbon Capture - Monitoring, Safety, and Geologic Impact of Underground CO2 Injection Feb. 8, 2024

Gideon Futerman, Researcher, interaction of SRM and Global Catastrophic Risk, Center for the Study of Existential Risk, Cambridge

Recording: What's the worst that could happen? Interaction of SRM and Global Catastrophic Risk Jan. 25, 2024 

Companion Materials:  

SRM Workshop Report


Viktor Jaakkola, Operaatio Arktis and Hugh Hunt, Deputy Director, Cambridge Centre for Climate Repair,

Recording: Experiences and Impressions of COP28 Jan. 11, 2024

Robert Tulip, Researcher and Author, Climate change, Jungian psychology, mythology, astronomy, and religion.

Recording: Religion's Ambiguous Relationship with Climate Change Dec. 14, 2023

Companion Paper: Religion's Ambiguous Relationship with Climate Change

Bruce Melton PE, Director, Climate Change Now Initiative; President, Melton Engineering Services, Austin.  

Recording: A Photo Journal of Climate Impact Across America Nov 30, 2023

Michael MacCracken,  Chief Scientist for Climate Change, The Climate Institute. 

Recording: Communicating with Decisionmakers on Climate Change November 16, 2023

Doug MacMartin, Associate Professor, Mechanical and Aerospace Engineering, Cornell University 

Recording: Sunlight Reflection Methods Nov. 2, 2023

Slides: Overview 2023

Alan Gadian, Visiting Scientist, National Center for Atmospheric Science and Research Scientist, University of Leeds 

Recording: Is the planet really being cooked? What can be done about it quickly? Oct. 5, 2023

Chris Field, Co-chair of Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) Working Group 41 on ‘Ocean Interventions for Climate Change Mitigation

Recording: Conversation about the Overshoot Commission Report Sept 21, 2023

Podcast: HPAC takes over the Reviewer 2 (R2) podcast!

Chris Vivien, Co-Chair WG41 Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP)

Recording: Governance of Ocean Intervention for Climate Intervention Aug. 24, 2023

Slides: The London Protocal and Marine Geoengineering

Why it is Not a Good Idea to Fertilise Ocean Gyres?

Phoebe Barnard, Founding CEO/Exec Director of the Stable Planet Alliance 

Recording: The Global Restoration Alliance July 13, 2023

Oliver Morton, Editor, The Economist; Author, The Planet Remade: How Geoegnineering Could Change the World

Recording: Conversation with Oliver Morton June 29, 2023

David Spratt, Research Director at Breakthrough National Center for Climate Restoration

Recording: Conversation with David Spratt April 20th, 2023

Dr. David Keith, Professor of Applied Physics and Public Policy at Harvard, Founder of Carbon Engineering

Recording: Conversation with Dr. David Keith April 4, 2023

Zeke Hausfather, Climate Research Lead at Stripe, The Breakthrough Institute Senior Fellow

Recording: Conversation with Zeke Hausfather March 23 2023

Robert Chris, Researcher and Author, Systemic Factors influencing global climate policy; PhD, Philosophy 

Robert Tulip, Researcher and Author, Climate change solutions; Australian Agency for International Development, 1989-2017;
      Master’s Degree, Ethics and Ontology

Recording: Two Roberts Wrestle with Moral Hazards March 9, 2023

Dr. Martha Schwartz, Research Professor, Harvard Graduate School of Design

Recording: The Urban Landscape and The Future of Cities February 26, 2023

Slides:   Climate Change and the Urban Environment

Luke Iseman, Co-Founder, Make Sunsets

Recording: Make Sunsets Overview February 9, 2023

Brad Ack, Chief Executive Officer, Ocean Visions

Recording:  Advancing Solutions for Ocean-Climate Restoration,January 3, 2023

Dr. Shaun Fitzgerald OBE FREng,  Director Centre for Climate Repair(CCRC), Cambridge

Recording: CCRC Climate Solutions Research Update December 15, 2022

Slides:        The Three "R's" of Climate Repair

Panel discussion: Is BioChar A Climate Solution?

Recording: Expert BioChar Panel Discussion facilitated by Dr. Brian von Herzen,December 1, 2022 

Slides:       BioChar Herzt Summer Workshop

Peter Eisenberger, "Rapid Scaling of Equitable Climate Innovations" 

     Recording: Rapid Scaling of Equitable Climate Innovations November 17, 2022

Andrew Lockley, Research Associate, University College London 

   Recording: The Case for Geoengineering October 20, 2022 

Dr. Jesse Reynolds, Executive Secretary, The Climate Overshoot Commission

Recording: The Climate Overshoot Commission September 8, 2022

Slides:   Dr. Jesse Reynolds, Climate Overshoot Commission HPAC Presentation

Soumitra Das,  President, Healthy Climate Initiative

Slides: Climate Benefit Concert for Saving the Himalayan Glaciers August 5, 2022

Ye Tao,  Founder & Director, MEER

Recording: Solar Radiation Management: Cooling the Planet with Surface Reflectors April 21, 2022

Robert Tulip,  Director, Iron Salt Aerosol

Slides: 1. Climate Arithmetic 2. Global Solutions 3. A Starting Point April 7, 2022

Stephen Salter, Professor Emeritus, Engineering Design, University of Edinburgh

Recording: How Marine Cloud Brightening Can Cool the Planet March 23, 2022

David Mitchell, Associate Research Professor (Emeritus), Division of Atmospheric Sciences, Desert Research Institute, Reno, Nevada

Slides: Can Cirrus Clouds Cool the Arctic? March 10, 2022

Will Burns, Visiting Professor, Environmental Policy & Culture Program, Northwestern University 

Recording: Climate Change Solutions Governance Issues

Brian Von Herzen, Executive Director, The Climate Foundation

Recording: Restoring Nutrient Value Chains via Marine Permaculture (and winning the XPrize for Carbon Removal Milestone)

Ron Baiman,  Author and Associate Professor of Economics, Benedictine University

Recording: Our Two Climate Crises  March 5, 2022

Slides: Our Two Climate Crises Challenge

References: Our Two Climate Crises Challenge: Urgent Cooling and Long-Run GHG Removal & Ecological Regeneration August 1, 2022

Tom Goreau, President, Global Coral Reef Alliance

Recording: Biorock Technology for Marine Ecosystem Restoration, Shore Protection, and Climate Change Adaptation Feb. 25, 2022

Bru Pearce,  Author and Director of Management, Envisionation

Slides: Envisionation: Biosphere Restoration Plan February 2022

Rafe Pomerance, Senior Arctic Policy Fellow, Woodwell Climate Research Center,

Recording: A Conversation with Rafe Pomerance December 16, 2021


The Arctic is Warming Four Times Faster than the Rest of the World, Paul Voshen; Science, December 14, 2021

US Arctic Report Card Is Incomplete, Zaelke, Dreyfus, Pomerance, & Bodansky; The Hill, December 14, 2021

Herb Simmens, Author of A Climate Vocabulary of the Future 

Slides: Climate Restoration Through the Climate Quad September 29, 2021