The recording of this discussion between Dr David Keith and the Healthy Planet Action Coalition is at https://www.youtube.com/watch?v=bCwvlPQWl8Q
Here is my summary of Professor Keith’s answers to questions. He began by mentioning his recent move to the University of Chicago to lead a Climate Systems Engineering Initiative. Support from geophysical sciences and other areas includes many faculty wanting to work on this topic including in solar geoengineering, cryosphere, carbon removal, geophysical models and public policy. The first question was on the relation between solar geoengineering and carbon dioxide removal. Dr Keith said the risk of CO2 in the atmosphere requires a combination of CDR and SG with decarbonisation and adaptation, but cutting emissions only stops things getting worse. Reducing temperature over centuries is better by CDR, but over decades favours SG regarding costs and risks. On tipping points, Dr Keith said they exaggerate the science. Most are far in the future and uncertain. The notion of planetary boundaries is profoundly false. He is extremely keen on field testing of SG. Models have uncertainties that can be studied by observation and experiment. On a question on CO2 outgassing from the ocean, Dr Keith said models calculate how much CO2 returns to the atmosphere from the ocean when CO2 is removed, with about half emitted CO2 still in the atmosphere. On carbon capture, Dr Keith said companies can only make money by demonstrated engineering results. He founded a carbon capture company that now has 170 employees. For SG the problem is different – knowing atmospheric effects by science. The biggest issues are trust and results. Incentives are similar to other social objectives, based on confidence in estimates driven by open science. SG is cheap, needing government and philanthropic funds. On a question about heat decline after net zero emissions, in view of ocean heat, he said papers on long term warming are available. He questioned the need to start cooling just at the poles, in view of ratio of sulphur to radiative forcing, impacts, ethics and economics, looking instead to biggest effects on hottest places. Cooling the world with sulphate aerosols can deliver global effects. He questioned the hysteresis of sea ice, and did not answer a question if we could stabilise the Arctic on a time scale to prevent loss of summer sea ice. Assumptions about time scale vary. He does not see a time scale of years for SG research. There are strong arguments for beginning slow deployment soon, but climate is slow moving. He does not see strong evidence for Antarctic tipping points, and sees a disconnect between climate scientists and student’s views of the climate crisis. Tipping points are vastly over-emphasised. It is easier in social experiments to get agreement when you have a sharp threshold, but climate has a huge spread of uncertainty about non-linearities. It is hard to detect surface temperature response signal from SG testing, although radiative response can be detected. Uncertainties on radiative forcing, effects of descending aerosols on the upper troposphere, size distribution of particles, chemical effects, organics in aerosols, can be tested for stratospheric response to infer radiative forcing. He said hearing questions respectfully, explaining facts and separating facts from values can engage people. A small group oppose SG, but mainstream climate groups are careful in their views and mostly take middle positions. Most support research. It is important not to overstate opposition, in view of strong interest in research. The Non Use Agreement see they are losing out. The Global Overshoot Commission is the highest level political group ever to engage these topics, with four former heads of government involved. Leader conversations engage high uncertainty, with SG alongside war and epidemic and economic crisis. We will not get international unanimity, but coalitions of countries are plausible for international architecture. There is no simple answer to the safe CO2 threshold. Saying we want to go back to Holocene CO2 levels is not a widely shared view. The planet can survive with higher CO2. Many differing viewpoints exist, with differing values about the safe CO2 threshold. Acid rain is proportional to sulphur, which previously had concentrated emissions of one hundred million tonnes, compared to one or two million tonnes of sulphur for SG, clearly indicating acid rain is not a big risk. The biggest political problems are to get a stable agreement, and that SG will reduce the pressure to cut emissions. Moral hazard is the biggest underlying concern. On SCOPEX, what happened in Sweden was not a problem with what the Sami said, but that the Swedish Government told the balloon operator to stop, even though it was legal. There is less opportunity in the US for government to stop something that is legal and permitted. The scientific utility has been undersold. The question is of considering a whole set of things to move forward. The Sami Council strenuously avoided talking to the SCOPEX project. Part of their view was related to mineral exploration disputes with the government. The project sought consultation but was politically outmanoeuvred. The short life time of methane differs from CO2. Methane contributes to feedback. Dr Keith provided these answers to audience questions over one hour. The meeting continued for another half hour. Recording is at https://www.youtube.com/watch?v=bCwvlPQWl8Q Regards Robert Tulip <https://www.healthyplanetaction.org/> https://www.healthyplanetaction.org/ From: [email protected] <[email protected]> On Behalf Of H simmens Sent: Wednesday, April 5, 2023 1:21 AM To: healthy-planet-action-coalition <[email protected]>; Planetary Restoration <[email protected]>; via NOAC Meetings <[email protected]>; geoengineering <[email protected]>; Healthy Climate Alliance <[email protected]> Subject: [prag] REMINDER HPAC meeting today at 4:30 PM EDT with Dr. David Keith The Healthy Planet Action Coalition will host a public question and answer session with Dr David Keith, Director of the Harvard University Solar Geoengineering Program. Meeting link: <https://us02web.zoom.us/j/88954851189?pwd=WVZoeTBnN3kyZFoyLzYxZ1JNbDFPUT09> https://us02web.zoom.us/j/88954851189?pwd=WVZoeTBnN3kyZFoyLzYxZ1JNbDFPUT09 Meeting Time: Tuesday 4 April, 4.30pm EDT Information about Dr Keith: <https://keith.seas.harvard.edu/people/david-keith> https://keith.seas.harvard.edu/people/david-keith HPAC is pleased to present this opportunity for conversation with one of the leading climate policy analysts working today. 4.30 pm Tuesday EDT = 6.30 am Wednesday 5thAustralia AEST and 9.30pm Tuesday 4th UK BST. <https://www.healthyplanetaction.org/> https://www.healthyplanetaction.org/ Herb Simmens Author A Climate Vocabulary of the Future @herbsimmens -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/geoengineering/2f0201d967d4%24f0c7bd90%24d25738b0%24%40rtulip.net.
