Thread by @Eaterofsun

carbonbrief.org/the-carbon-bri…
Today @carbonbrief has a big interview with @BillHareClimate of climateanalytics.org It covers many topics, some fascinatingly. But I want to take issue with some things he says about solar #geoengineering, aka #SRM or #SolarRadiationManagement 1/

Dr Hare tells @LeoHickman that, “along with...most physicists who have looked at” solar geoengineering, he thinks it is “a very dangerous technology”. There are forms of solar #geoengineering which could indeed be very dangerous. Two points to make about this: 2/

One: as @jack_stilgoe, @rose_cairns, Steve Rayner and others point out, geoengineering is not yet a technology; it is poorly defined conceptual space where a technology might be – a “technological imaginary”, as social scientists sometimes say 3/

Definitive statements about it are thus unwarranted. It can't be averred to be unproblematically good, or useful. It could definitely be developed in a dangerous way. But there is no "it" that can be essentially dangerous 4/

Two: I would guess that most researchers (casting the net a little wider than Bill’s “physicists”) who have looked at solar geoengineering would agree about the risk of danger 5/

But if the conversations that I have had with many of them are any guide, most of those working on this form of geoengineering would tend to put that danger in the context of the dangers of not trying to understand the technology's potential. 6/

This is not to minimise the danger; it is to put it in the context of other great dangers. 7/

Dr Hare also says that “solar radiation management technology as a branch of geoengineering is being aggressively pushed now”. 8/

“It’s ... a discredit to those pushing [solar geoengineering] that they are ..[o]ut there in their pamphlets, brochures, lectures and talks claiming that mitigation has failed, and, therefore, we need to look at these very dangerous technological approaches.” 9/

I don’t recognise this aggressive push. I don’t know what organisations he thinks are doing the pushing, or what brochures and pamphlets he is worried about. Harvard has set up a centre for studying solar geoengineering... 10/

..which is planning an experiment, #Scopex. On the west coast there is interest in trying out a cloud brightening system to see how well it might work. I don’t see that this constitutes an aggressive push. 11/

But it’s the point about writing off mitigation that really gets to me. Dr Hare goes on to repeat the point: “The people calling and doing these experiments are also promoting, in different ways, the use of solar radiation management and claiming that mitigation has failed.” 12/

Having written a book about taking the potential of solar geoengineering seriously, and having heard a fair few of the relevant lectures and talks (by eg @David_Keith, @kellywanser, @KenCaldeira and Tom Ackerman) I hear no-one saying that mitigation has failed. 13/

When I talk about this, and when I hear anyone else who knows about this stuff do so, I always say or hear, loud and clear, that mitigation is the number one priority. 14/

If Dr Hare or @CA_latest knows of people in the field who see mitigation as a failure and tout solar geoengineering as an alternative to further efforts towards ambitious emissions reduction, I’d like to have them named. 15/

I am ready to believe in them. But I do need to see them, 16/

It is true that people in the solar geoengineering community are probably, on the whole, less bullish about 100% renewables than Dr Hare is. 17/

He says “There’s not going to be a general answer to that everywhere but if you look at the scientific assessments that have been done of this, there are few technical obstacles to being able to run 100% renewable systems.” 18/

Many people who research solar #geoengineering (and energy systems and climate responses more broadly) would baulk at that (see eg Clack et al pnas.org/content/114/26…) 19/

And even Bill doesn’t seem very sure. “Coal emissions are dropping. That may continue,” he says. If he thinks it may not then there are real issues to address. 20/

To wrap this bit up: There is real straw manning going on here, with the invocation of people “aggressively pushing” solar geoengineering by saying that “mitigation has failed”, when in fact... 21/

...there are people cautiously exploring possible ways to make solar #geoengineering a just and governable way of reducing harm while continuing with the vital work of mitigation. 22/

One other little thing. Dr Hare is quite big, in this interview, on direct-air capture. He is also very keen that this *not* be seen as “geoengineering”. Climate analytics has published a position paper on this climateanalytics.org/files/why_net_… 23/

I think there are a bunch of issues with that paper.
I know that there is a range of opinions on “lumping” v “splitting” when it comes to solar geoengineering and carbon reduction (indeed I got an email from a friend about it this very morning!). 24/

I tend to be a lumper, because both offer global ways to respond to carbon already emitted, and that seems to me to set them apart. I accept that others think they have good reason to reach the opposite conclusion. 25/

But in the Climate Analytics discussion I get a distinct sense that the reason for splitting pretty much boils down to “We like carbon reduction. We don’t like solar radiation management... 26/

.... And so we want to have the word geoengineering, which we think has negative connotations, reserved for the thing we don’t approve of..."
Maybe I’m wrong – would be interested in what other people think. 27/

Anyway, I note that in the Carbon Brief interview, Dr Hare refers to “solar radiation as “a branch of geoengineering”. If he really doesn’t think carbon-dioxide reduction is a branch of geoengineering, what other branches are out there? :-) 28/fin

PS: two twitter handles wrong in this: @Jackstilgoe and @DKeithClimate -- apols