Some people -- including Harvard researcher Ye Tao -- believe that even aggressive decarbonization will still leave the Earth too hot to bear. He has developed a new idea for large-scale geoengineering: he wants to directly cool the Earth's atmosphere by covering large swathes of land & ocean with cheap mirrors. It's brash & ambitious, but the numbers show it could work.
This is really compelling - thanks David. Has Dr. Tao published anything peer reviewed on this? The most compelling piece for me is the idea of local benefits for deploying a global solution - I'd be curious to learn more about the results of his studies on agricultural productivity & urban comfort. I'll keep digging around & post anything I find here but if anyone else finds something worthwhile please do the same.
I was *very* pleasantly surprised by this podcast. I was expecting a crank (except that it was on Volts), and got someone who has an amazing handle on the scales of both the problems and solutions. Echoing comments below, I'd love to see peer-reviewed work and/or other scientists' takes on his arguments and work (including materials scientists on whether the structures are as durable as he claims). I especially thought his point that farmers are already shielding their crops with something fairly similar was quite compelling, from a "could this actually be implemented widely" perspective.
For anyone tempted to comment without listening - give it a listen first; he probably addresses your question/concern.
This was a very interesting discussion (as always!). We need as many tools in the climate fight as we can get, and mirrors are a fresh addition to the toolkit. The fact that they can deliver local benefits, thus yielding "selfish" motivations that could drive deployment, is promising.
However, I'm confused about the things Dr. Tao says about the trajectory that we're on if we don't find some dramatic new intervention (such as mirrors). Specifically:
1. His statement that we have about 1.5°C of additional warming already locked in due to inertia effects (from the 1.5 W/m^2 of current net energy influx). This seems blatantly inconsistent with the IPCC scenario forecasts?
2. His statement that CO₂ capture (DAC) is "dishonest", in that at best it can barely provide enough cooling to compensate for the emissions generated to build and operate the capture process. I can't begin to do the math on this, but plenty of people who'd I assume *can* do the math, are on board with DAC as being part of the solution.
3. The warming spike that we'll get when we stop emitting aerosols. That's true, but there are counterbalancing effects that he did not mention. If we're able to reduce emissions of short-lived GHGs such as methane and carbon monoxide, that should more or less balance the loss of aerosol cooling. (Explanation at https://climateer.substack.com/p/aerosols; disclaimer, that's my personal blog.)
Can anyone shed light on this?
If we survive, it will because we learn to work with nature, rather than trying to control it. Much work is ongoing in the field of regenerative agriculture which provides a mechanism to transform deserts into productive, cooling, water retentive grass lands. An excellent example can be found at:
There are many more.
These types of improvements can be accomplished on all sorts of physical scales and climates and has the benefits of cooling the earth, improving soil health, reducing chemical inputs, increasing water infiltration, reducing labor, and increasing profits, all while capturing and sequestering carbon. All free and all you need is a diverse selection of seeds, grazing animals, human labor and a year or two for the changes to begin. This approach also produces food. It is nature based geoengineering. It is not something agribusiness is interested in due to the reduction in required inputs. The disinterest is similar to the interaction between solar and the fossil fuel industry, because both approaches reduce our dependence on these industries.
The human race has a long and well established history of desertification: the process by which fertile land becomes a desert, typically as a result of drought, deforestation, but mostly because of inappropriate agriculture practices. Counter these approaches and great things can happen. Imagine turning all the deserts our species has created back to fertile productive land. This is possible. So I would like to see a calculation that proves that mirrors are better than a nature based approach to cooling our planet. I think nature will out perform the mirrors. Similar work can be done in the oceans of the world.
That conversation was the most vertiginous ride I've been on in a while - from despair that we're already past 2 deg, to discovering a new source of much-needed hope that there might be a relatively simple, quick, reversible cooling solution with possible co-benefits. Eager to see how this develops.
Having 2 geoengineering pods on my feed within days, I of course had to listen to them both. This is a more general view than David's deep dive as its aimed at a more general audience. No mention of mirrors at all which one can take as a sign that it's not yet a viable option or just not the expertise of the interviewee here.
I hope this link works and some may find it interesting. There are interesting fairly varied people who come to this one so you may want to sub too. 😊
[People I (Mostly) Admire] 79. Solar Geoengineering Would Be Radical. It Might Also Be Necessary. #peopleIMostlyAdmire
https://podcastaddict.com/episode/140998014 via @PodcastAddict
Looking for climate/sustainability-related book recommendations! I have $500 worth of professional development funds available to me at work and I'd like to spend it on books - thought this would be the perfect place to get recs! Thanks in advance!
Two points seem to have been missed:
* This does not address the increasing acidification of the oceans, which is seriously threatening all sea life--especially that which we depend on most.
* It did not address the likely problems of weather phenomena resulting from the use of such cooling agents. Any time a cool front meets a hot front, there is turbulence and a potential for storms. Doing this on a level that could change the course of the climate emergency could promote major weather phenomena. This was not mentioned.
I vote we reduce fossil fuel use on an emergency basis. If this was being addressed as the emergency it is, we would already be reducing speed limits to 55 mph, and connecting our grid up as though it were a wartime project. This may seem extreme now, but it will not in 4 years, to say nothing of 7 years.
I found this discussion to be fascinating and would love to learn more, and to hear perspectives from folks who might disagree with Dr. Tao's analysis. A question I have for Dr. Tao: I have seen the idea of white roofs discussed now for a number of years as a potential approach to ameliorating climate change. It seems to be a similar logic to your proposal of mirrors. I am curious about the pros and cons of white roofs vs mirrors vs some combination of both?
If it is too good to be true, maybe take a deep dive. I for one see no depth to MEER. No numbers, no modeling, no equations, no PHYSICS. Maybe before Dr. Tao worries about how to explain MEER to non-scientists, he should worry about explaining it to scientists?
Wondering what you think of the approaches Peter Fiekowsky suggests in his new Climate Restoration book. They're not exactly geo-engineering but related, and address the same issue that we have to remove carbon as well as stop adding it.
Ocean pasture restoration; synthetic limestone manufacture; seaweed permaculture; and methane oxidation
Space is pretty big and L1 is definitely not a crowded place like low earth orbit, but James Webb just took a larger than expected micrometeorite strike at L2 so it isn't empty either.
The good news is that a micrometeorite strike doesn't cause a lot of trouble if you don't resist it. Let it blow through and avoid absorbing its kinetic energy. A micro-scale hole in a 2M sq. km array isn't a large degradation. There are several approaches to creating a solar shade and very few envision a rigid structure that takes a hit and shrugs it off. Mostly there are micro-mirror satellites in a cloud and if one gets hit it just gets popped out of the array, or ultra thin materials that are easily pierced. Shedding heat and station keeping around the saddle point are bigger problems for anything large at L1 - even if the thing is just serves as a diffraction grating in space to scatter the sun.
The good news, there will be plenty of solar power available to put to work. The challenges are around mass and coordination of such a large array.
Any array wouldn't be earth sized, though. We're only trying to adjust a few percent of solar incidence; but a 2,000km per side 'thing' in space is still silly-big no matter how small its component parts or thin its pieces.
Is periodic cleaning required?
I was a little bothered when Ye Tao said that the solar insolation was 1.5 Watts/square meter. I always knew that that the sun's power was 1.0 Watt/square meter. Otherwise, it was and interesting proposal. However, I believe that increased solar and wind power can stop continued global warming.
Great interview. This feels like a thought experiment scaled up insanely.