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| 00:00 | if we could increase the reflectivity of the earth by half a percent we've solved a problem and one way we might be able to do this is to change the reflectivity of clouds and that's what these ships are doing [Music] well good evening everyone and thank you all for taking the time to be here tonight uh we're near on through uh midway of this cop here in glasgow and certainly you've all heard the dire situation that we're in and indeed that's not to discount it it's very dire indeed |
| 01:02 | but we're here tonight to offer you a bit of hope on this program uh that we're bringing you on marine cloud brightening and this is a climate emergency forum program in conjunction uh with facing future tv and we have a few special guests tonight and i'd like to introduce our main speaker of the evening who's dr steven salter and he's emeritus professor of engineering design at the university of edinburgh and has been one of the leading voices of the marine cloud brightening movement and he's here to teach us a bit about it |
| 01:47 | and offer us a glimpse of the promise of of hope in this movement so without further ado thank you the greenhouse gases are increasing the amount of heat we're retaining by about 1.7 watts per square meter and the uh the sun is putting in about 340 watts per square meter over 24 hours averaged over the over the earth so if we could increase the reflectivity of the earth by half a percent we've solved a problem and one way we might be able to do this is to change the reflectivity of clouds and that's what these ships are doing |
| 02:37 | they are uh squirting out very very small drops of filtered sea water 0.8 of a micron diameter these uh going out horizontally but because of the cooling of the evaporation of the air and they evaporate um they uh will be going down they'll won't go into the sea uh because the air is keeping is not going to see and they're glued into the air but they'll warm up from the sea and then they'll get up to the cloud level and the job they can do is really quite useful they are cooling i've got different areas here for an el |
| 03:19 | nino or american or an arctic ice and the bottom line of there is the number of vessels that we would need to work at full power maybe they won't all be for doing jobs in in different periods and you'll see that for reversing sea level with 20 years if we did 20 years we'd need 400 of these ships to do it and if we wanted to uh save the arctic ice we just want uh 42 vessels which would have to do the job in uh just 60 days outside of mid-summer this is why we have to do it you can decide what the chances are of |
| 04:04 | putting carbon dioxide concentrations back down that's the keeling curve which must be very frightening this is the amount of energy beats been going into the deep oceans and a zetta jewel is about twice uh the total human energy consumption of all forms of energy i didn't know what a zetta jewel was until i started this it is showing different sea water temperatures over the oceans complicated or interesting and we may need to do different things in different places that's the separation between the different oceans |
| 04:44 | now the number of dots there is a representation of the total solar input and if you look at the tiny little thing down there that's the uh the the human energy consumption in all um in all forms that really makes you it hits you in the gut with the the difference between the solar input and what we're actually doing there is a rather familiar slide but if you look at this one you'll notice that the uh the the top arrow is going to rather white bit of cloud and the lower arrows really grey a bit of cloud |
| 05:27 | this chap here called sean toomey he really started all this business was very interested in why some clouds were whiter and sometimes were grey and he was able to fly over them and measure the light coming down from the sun and the reflection coming up and he could fly into them and he could scoop up samples of cloud drops and see how big they were and how many they were what the concentration was and he produced lots of really heavy algebra which you can condense into one uh one slide the vertical axis is different amounts |
| 06:06 | of power or albedo or reflectivity but the key is the horizontal line where it's the relative number change of the cloud drops so you can choose the amount of energy that you want to reflect uh up and down the vertical lines whether it's the the cloud or the top of the atmosphere you slide along until you hit the slope line and then you drop down that'll tell you how much how many how much you want to multiply the crowd cloud drop concentration there is a photograph showing i've got another copy over here showing the |
| 06:43 | effect of larger number of smaller drops being white and the small number of big drops being gray those are glass balls so it's the same material in the same shape just different sizes four millimeters on the left the grey one and about 40 microns 100 tone ratio this chap here knew all about this and he suggested that we might be able to cool the earth by spraying sea water since his his idea and you'd have thought there'd be a fairly even distribution of drop sizes in the atmosphere but there are there's three |
| 07:21 | different modes and uh the course mode is not big enough to show on this this diagram we want to spray where the red arrow is which is point eight of micron that would if that evaporated down to a completely dry solid it would be about 200 nanometers and we think we need a rather narrow spread on that uh this is a plot of all the estimates made of all the amount of sea that's sea water that's been thrown up into the atmosphere plotted against the year that they are made all right and you can see that it must be rather |
| 08:02 | difficult thing to measure the average value is a little blue circle there and if you look carefully you might just see a thickening of the of the black line of the horizontal x-axis and if we were trying to have a thousand of our vessels working flat out full power they would be producing the thickness of that line so it's not the amount of water we're putting up it's the number of successful nucleations and that depends a bit on the getting the right size and that's what they look like again and that's |
| 08:38 | what the engineering would look like you won't be able to see any of the detail of that at this scale but it shows that we are really well ahead in choosing seals and bearings and those thicknesses of of all the sections and they're driven not by sales but by things called fleckner rotors and this was built in 1926 the original ones and they're now being introduced into quite large ships and they're saving quite large amounts of of fuel this is a result of some work in norway where they were a bit more intelligent than most of |
| 09:22 | the climate modelers and they decided it would only be a good idea to spray where there were low clouds over the oceans and what they did was to double no that what they did was to increase the nuclei concentration by 50 which is quite a modest change and you can see there's a really big concentration of cooling right up in the northern areas which is extremely welcome and that's on the right hand uh map and then the left-hand map you can see what it's doing to precipitation and you'll see that there's greeny blue |
| 09:57 | bits in the sahara in australia and mexico and south africa so it's increasing the amount of precipitation in the in the drought-stricken regions and where it's reducing precipitation it's over the sea where nobody really cares very much if there are small islands there we could perhaps provide them with desalination plant and nothing we can do is to cool the sea to moderate hurricanes and that map is showing you where the hurricanes start and where they get bigger and the ones that get publicity are the ones that hit america |
| 10:34 | and you see they you usually start in the in the cap verde islands over on the african side and what we could do would be to have fleets of vessels that were cruising around starting in november and through the year if they would be measuring the temperature service temperatures and you do just the number of them to match the required choice of sea service temperatures that was chosen by the governments of the countries in that area no one's brave enough to say we'll promise you no more hurricanes but we they can say we'll get |
| 11:09 | you down from 26.5 to 23. and you propose how close we can get and there is a a a table again of all the jobs that we might do uh i think these would depend very much on the initial concentration of nuclei and the live drop life of the ones that we spray and i i'd like to put a big factor of safety on that but they're not absurdly um are out um it's very difficult to get a cost estimate of anything if someone loses their job if they revealed the secrets of a commercial company what you have to do is to look around |
| 11:54 | for something that's similar in production rate and in power and weight and working conditions and the only one i've been able to find so far to help us estimate the cost of spray vessels is the flower class corvettes that were built for the royal navy in 1940 and they cost 60 000 pounds and if you index linked that till today it's about a factor of 50 increased um chief scientific advisor was paid 600 accordion rv jones he was bent the beams that were navigating the luftwaffe and if we wanted to have a fleet of 800 of those |
| 12:41 | it would cost about 240 million pounds a year to pay the bank and do the maintenance and i picked 800 because i'm told that the cost of security for this conference was 250 million so it would be cheaper to have a fleet of 800 corvette replacement spray vessels than to have this conference now we'll come back thank you thank you so much for that uh professor salter um i'm perf i'm particularly astounded at the affordability of this uh of this option uh 200 less than 250 million pounds uh a year to enact this and it's amazing that just by |
| 13:27 | brightening the clouds themselves which this technology promises to do we can increase the albedo and and thereby decrease um the the global warming averages and the money we save could get more policemen right exactly exactly so thank you so much for that and now i would like to introduce uh dr peter wadhams to my left here and dr peter wadhams is a professor emeritus of ocean physics and head of the polar ocean physics group in the department of applied mathematics and theoretical physics at the university of cambridge |
| 14:08 | he's best known for his work on sea ice and he's author of the uh well-known book of farewell to ice so with that i'd like to turn it over to dr wadhams thank you uh well there are many aspects of me cloud brightening which make it very especially attractive as a means of cooling the world or preventing it from warming so much the first one is that uh unless comparing it to a technique which has been tried uh but i find rather less attractive is that you can turn it on and turn it off when you when you want when you want to to produce the |
| 14:50 | the cloud brightening effect uh you and you switch on the pumps you have you have n ships each of them uh using these fine nozzles to pump um finely divided seawater particles into the cloud but as soon as something happens that you don't particularly like for instance clouds are um uh but you are coming up in the wrong place or not going to the right place you can you can simply stop pumping and and stop so you stop and start whereas with uh aerosols which is the other technique of geoengineering that's being tried you |
| 15:36 | have to um release a large amount of very fine aerosols which might be toxic into the upper atmosphere and then you just have to sit there while they gradually fall out and they may fall out in a way that you don't like that would do something dire to the uh to the world weather systems so it has the advantage of of immediate control it has another advantage to this non-toxic and the the level of in of knowledge and well they would say intelligence of a lot of the public to doing with climate controlled efforts makes them |
| 16:17 | terrified that if you put aerosols into the upper atmosphere everybody will be poisoned and so there's no danger of that with with water sea water and the the other thing is that the fleet of ships that you need which as stephen has shown his remarkably small number of ships and remarkably um low cost um but they can be dispersed or concentrated in the way that you want that will fit your model of what you need to do if you want to focus the the cloud brightening on one particular region one one that's been modeled very |
| 16:56 | intensively is the arctic and the idea there is that uh you you you focus the the input of uh cloud brightening into into clouds that are heading for the arctic warm in that way cool down the arctic and uh prevent it from doing some of the things that we mentioned at the last talk which is melting too rapidly and causing release of methane we can actually try to re-freeze the arctic to some extent and the models say that this would work it doesn't completely refreeze but it does do do a lot of go a long way towards |
| 17:38 | slowing down the the the impact that the warming water would have on uh methane release so in in many many ways it's it's attractive and stevens also mentioned hurricanes as well and it's the role that cloud binding would have in moderating hurricanes and other weather systems it's um it's it's acting as a moderating influence everywhere in the world so given all these advantages it is a negative miracle i suppose that this hasn't been taken up as the the most important and most uh fully |
| 18:20 | supported method of of geoengineering for restoring the world's climate um and i don't understand why that is and i think we hope that in the greater understanding that we now have from for of climate change and hopefully the greater enthusiasm and the great amount of funding now available as we can see from this meeting uh that that it will find its its true its true metier at last and especially since the person developing it comes from this very country that is sponsoring the uh cop um so i'm hopeful that at long last marine cloud |
| 19:10 | brightening will get fully supported and it doesn't do away with carbon dioxide of course no system that's geoengineering does that but it will call the climate enough to to prevent some of the worst extremes from happening um it will it won't prevent the ocean from getting more acidic which is a problem that that we get from now from from acidification of the ocean from extra carbon dioxide dissolving but it will do a lot and it's it could be it could be the sticking plaster that would hold the thought between doing |
| 19:53 | nothing about global warming which is what present policy and spoken policy seems to be and and the policy of actually taking carbon dioxide out of the air in a systematic or out of the sea in a systematic way that will bring down co2 levels so this could be the sticking plaster that does the job of keeping us keeping us all surviving until these other methods come along so i recommend it strongly thank you so much for that um i really i really like um in terms of geoengineering as i i mentioned in a program yesterday it's the uh it's sort |
| 20:35 | of the the uh the word that dare not speak its name a lot of people are frightened by it and um i myself can understand that but what is so um enticing about this particular geoengineering scheme is the the flexibility of it and um and as you had said uh dr wadhams that this idea of immediate control this ability to turn turn it on and turn it off and in fact since it's dependent on these boats that can travel and go to various problem areas it's targeted right so it's it's not something that it's like okay well let's |
| 21:14 | emit something into the atmosphere and and see what happens in a few days it's very targeted it's very neat it's very um controllable which i think makes this something that a lot of people would be amenable to so thank you so much for bringing those ideas to the fore and next up on our panel is paul beckwith and paul is a climate systems scientist who is taught at the university of ottawa in the laboratory for paleoclimatology as well as at carleton university he's a well-known uh scientist in this field and has produced |
| 21:54 | a tremendous amount of videos on the subject over a thousand as a matter of fact so paul thank you regina i used to read loads of um fiction novels horror novels by stephen king very famous american author he's written over 50 books horror books but i don't get the same feelings of of brightness and reading his books now all i need to do is read a climate paper you know a peer-reviewed climate paper either on you know the antarctic or on extreme weather events or what's happening in the arctic you know global food shortages |
| 22:38 | biodiversity extinctions all this stuff i mean that's you know the in these climate papers far exceeds anything any fiction that's been written so one of these papers um that i'm talking about very frightening paper uh just came out a few weeks before this conference and it argued that the average reflectivity of the entire planet which is normally known to people as about 30 percent it's difficult to measure you measure it from satellites up above the earth it the the paper argues that they've |
| 23:18 | measured that that reflectivity has decreased from 30 percent to about 29.5 percent a drop of about 0.5 percent and how they measure it is quite fascinating next time you're looking up at the moon the bright crescent that you see is called moonshine the sun hits the moon and reflects to the earth and our eyes see that crescent is bright the dark part of the moon is called earth shine and the sun is actually hitting the earth reflecting off the earth going up to the moon reflecting back to our eyes and we we can see it |
| 23:54 | often on clear nights and by measuring the reduction of that earth shine we can infer the loss of the reflective the reduction of albedo or reflectivity of the earth from the 30 to 29 for five percent now they say that they think that this has occurred has occurred in the last uh two three decades because of less clouds in the pacific ocean in particular there's a number of reasons why they think that there's less clouds but probably the most significant reason is that there's a lot less phytoplankton |
| 24:29 | in the ocean maybe 50 percent less now than there was in the 50s phytoplankton naturally produce chemicals once it's like like dimethyl sulfide which then rises into the arab of the ocean and acts as cloud condensation nuclei or there's also other phytochemicals from the plankton as uh russ george um an expert in that field explained to me last night so basically this the earth is getting darker we know the arctic is getting darker a lot because of the loss of arctic sea ice but it turns out that the overall planet is |
| 25:08 | getting darker so this marine cloud brightening method is a way to take the existing clouds and and and if you put in cloud condensation nuclei into the atmosphere over the ocean and make their size a specific size then the cloud droplets that form are much smaller so the volume of water in a cloud is enormous you're not adding to the volume but you're making the composition of the cloud being very very small droplets as opposed to large droplets if you see it approaching cumulonimbus storm cloud it's very very dark the droplets are |
| 25:51 | very large and heavy therefore and you know that there's going to be rain occurring so what this method does is as steven showed here is you make very very bright clouds like on the on the your right is the very small particles very small particles so it's very reflective versus the glass vial on the left where the drop the the your you've got a much larger particles and much darker much less reflective so the idea of spraying seawater through nozzles you can tailor the nozzle size so that you get water and the salting |
| 26:30 | clothes within the water and then when the water evaporates you get very specific size salt crystals which he studied carefully as to which size is optimum for the brightest clouds there's also a lot of other gains because the lifetime of the clouds is much longer if the water droplets in the clouds are much smaller and the reflectivity of course is much higher and you can change the reflectivity of the clouds in the regions that will benefit you most for example if you want to protect the coral reef you can generate |
| 27:06 | lots of clouds downwind and then the wind will blow these clouds over the region where the coral reef is and cool the water underneath um if you want to cool the arctic you would put them up in in in the north so the the warm gulf stream coming across would then be shielded you're putting basically an umbrella up on top of it to reflect away sunlight to cause cooling now climate change is really a warming ocean problem 90 over 90 percent of the heat coming into the earth is heating the oceans so if there's any way we can cool |
| 27:43 | regions of the ocean it's crucial and this does not affect the land at all because it there's very few cloud colonization nuclei over the oceans but there's tons of it over the land and near coastline so you're not affecting things on land you're just tailoring the clouds over the the oceans thank you so much for that clarification paul and i believe uh yeah yes it is a little good question for you to do for your homework uh you want to work out the energy that is reflected by a cloud drop |
| 28:20 | which will depend on its projected area about eight percent is reflectivity depending on wavelength compare that with the amount of surface tension energy that you needed to make the tiny little nucleus on which the drop grew the cloud dropped through up to 25 microns and uh we want the surface engine to make something that's about point eight of a micron and the number i won't be on to be sitting down when you do this calculation it's tens of millions and it's that that really makes this energy ratio |
| 29:00 | it makes the project work well thank you so much for that and thank you uh everyone on the panel who shed light on this really interesting geoengineering program uh that seems to hold so much promise and uh in the spirit of giving thanks i'd uh once again like to thank you for being here and thank the following organizations who've made it possible for us to present here tonight that includes the interfaith center for sustainable development the international society for ecological economics and the buddhist tsuchi |
| 29:35 | foundation so thank you to them and thank you to y'all and have a good evening [Music] [Laughter] [Music] [Music] you |