 Good morning everyone and welcome to EGU 22, the annual meeting of the European Geosciences Union. As many of you already know, this is the Union's first hybrid General Assembly, where we are bringing back our on-site experience for those joining us here in person, while at the same time introducing new concepts from the last couple of years to include our virtual attendees as much as possible. This year, we've had more than 12,000 abstracts submitted to EGU's meeting. And during the press conferences, we'd like to highlight some of the most unique studies, which, as you'll soon see, have impacts on local communities, industries, ecosystems and the global environment. I'm Gillian D'Souza, EGU's Media and Communications Officer, and I'll be hosting this week's press conferences. Each press conference will have time for speakers to make their presentations, followed by a question and answer period at the end. For those of you joining us virtually, I ask that you all mute your mics throughout the briefing until I call upon you to speak. If for some reason you experience technical difficulties, you can try to rejoin the session or look for more information on the press conferences section of the media.egu.eu page. A last couple of things to note, please save all your questions after the speakers have finished presenting. During the Q&A period, we will take questions from journalists both in the room and online. If you're in the room, please raise your hand so that I can pass a microphone over to you. And if you're joining us virtually, please use the hand-raising function of the Zoom platform so we can come to you for your question. And of course, if you like to prefer to type your question instead, feel free to do so in the chat. Alright, so now I'm going to go ahead and introduce all of our panelists to make for faster transitions between them. This morning's press conference is titled, Clues from the Past, a Galapagos who done it, Egyptian water woes and Judean famines. Our panelists today are Francesca Ghazale, who's joining us on site from the Department of Civil and Environmental Engineering, Polytechnico di Milano. We have Michael McFadden, also on site, who is from the National Oceanic and Atmospheric Administration, Pacific Marine Environmental Laboratory. And then we have Selga Medenix, who is accompanied by her PI, Frances Ludlow, both from the Department of History, from Trinity College, Dublin. Alright, so we are ready now to hear our former speakers about their exciting findings. Over to you, please. We'll start with Francesca. Good morning. I am Francesca Ghazale from Polytechnico di Milano, and I am a PhD student. And today I present some results of this study about the effect of climate change in the future on the Nile River Watershed hydrology, in particular in the area of Egypt. This work is developed by the Climate Lab of Polytechnico di Milano. Okay, so we study the hydrology of the Nile River Watershed, and we are doing some climate projections for the future. And at the end, we are comparing the results and the potential projections with some similar hydrological conditions of the past, in particular of the ancient Egypt. Indeed, we find a nexus between some changes in hydrology and climate in the past and some social and economic events, like, for example, social disorders, conflicts, but also plugs, famines, and displacement of population. The study area is the entire Nile River Watershed, and particularly Ethiopia, South Sudan, Sudan, Egypt. And we have to consider all the watersheds to simulate the hydrology of the Nile River Watershed, but then we consider, in particular, the results on the area of Egypt. For input data of the model that we use for the simulation of hydrology, we need data of precipitation and temperature. So we use daily data of precipitation from 20 automatic weather stations, and for temperature we use 13 automatic weather stations. For the calibration of the model, we use data of discharge from 10 hydrometers. These stations are distributed, homogeneously distributed, over the entire watershed, in particular in Ethiopia, South Sudan, Sudan, and Egypt. We consider the period between 1973 and 1984 as a reference for the present period. We can see the average precipitation and temperature for the entire watershed, but also for the equatorial area and the desert area. We can see that precipitation, we have a large amount of precipitation, in particular in the equatorial area. So the formation of discharge happens in particular in this area, and not in the north, where we have Egypt. Here I report some historical data that we collect from the past, since 3000 B.C. And we can see the social event, like for example plugs, famine and similar, and the correspondent climatic or hydrological events. So for example frequent floods, or on the contrary, a long period of low Nile river level. And for example we can focus on the last event of the end of the 12th century, and we can see that three years of low water level of the Nile river caused a period of drought and as consequence a famine period with an increase of food product price and as consequence at the end the death of a large part of the population. For the simulation of the hydrology we use this hydrological model that is polyhydro developed by Polytechnico di Milano, and it's a semi-distributed hydrological model based on the continuity equation applied to the soil-water content. We use a special resolution of 10 kilometers and a time step of one day. For climate projections we use six global circulation models of the sixth assessment report of the IPCC, so we use updated global circulation model. And for the scenarios of the projections we use for shared socio-economic pathway. For the analysis we focus only on two periods, one at the mid of the century and one at the end of the century. Okay, here I report some results for one global circulation model that is the Kama 6.3 and I report the results of precipitation, temperature, evapotranspiration and discharge for the reference period, so the 1973 and 1984, and the projections at the mid and at the end of the century for all the four scenarios. And in one table I report the absolute values of these variables and in the other table I report the variation with respect to the present period. In the last two tables I report the variation with respect to the present period for discharge and evapotranspiration for all the seasons. We can see that we have sometimes, for example, an increase of precipitation. In other cases we have a decrease and as consequence we have different behaviors and so different variations of evapotranspiration and discharge. Now we focus on one case that is the scenario 4.5 at the end of the century. In this case we have an increase of potential evapotranspiration related to the increase of temperature, but on the contrary we have a decrease of precipitation and a decrease of actual evapotranspiration. We have also a decrease of both the ratios, one between actual and potential evapotranspiration and the other between actual evapotranspiration and precipitation. We can see that these happens in particular in spring when we have the peak of temperature. For this reason we can think that this could be a case of drought, a period of drought with as consequence a lack of availability of water. In particular this could be a problem for hydropower production and in particular for irrigation and agriculture. We can compare this case study with this potential projection with that event of the end of the 12th century when for the same condition we have that case of drought, famine and the death of a part of the population. Obviously now and in particular in the future the global social conditions are different so probably the effect could be different but it's important to consider this kind of projection when governments plan the adaptation of the country to climate change because we can have different projections but it's important to plan the adaptation and we have to consider all the possibilities because they could have an important impact on the society and on the economy of the country. Obviously I report a case study, an example of projections and an example of comparison with the past. We are doing a lot of projections so we have a large range of potential projections, potential scenarios but we can do an average of the projections but it's important to consider all the range of projections and these possibilities and I thank you for your attention. Thank you Francesca for your presentation. We will now hear from Michael please. Thank you all for joining us today. I'm Mike McFadden from NOAA PMEL in Seattle, Washington and I'm going to talk about La Nina came to Eden and this is in reference to a Hollywood documentary that came out about 10 years ago. Let's see, there we go, called The Galapagos Affair, Satan Came to Eden and it's the story of a group of expatriate German settlers in the 1930s and their bizarre intrigues and struggles to survive on this remote and isolated island in the Galapagos Archipelago and what I will show you today is how La Nina affected the fates of these settlers and why that's still relevant to us today. So the documentary takes its title from a memoir of one of the survivors, Dore Strauch, Satan Came to Eden, published in 1936 and you can see her on the left and next to her is Dr. Friedrich Ritter, a Berlin physician whom she fell in love with and together they wanted to flee the beaten passive man, put aside all the irrelevant trappings of civilization and live in solitude and communion with nature and so in late 1929 they left Europe and established a homestead on Floriana Island in the Galapagos. They spent most of their time naked and they called themselves the Adam and Eve of the Galapagos. The word of their pioneering enterprise spread to the outside world and this publicity had the effect of attracting more visitors and one of them was an Erzatz Baroness from Vienna, Baroness Louise Wagner de Bousquet and her two German lovers, Rudolf Lorenz and Robert Philipsen. The Baroness is Satan in Dore's memoir. She quickly antagonized most of the other settlers and sowed a lot of discord on the island with just about everything she did and as Dore said, I felt as Eve must have felt on learning that the serpent was the evil one. Well, amidst all this drama and tension among the settlers, drought ripped the island and in early 1934 Dore says, the drought began towards the end of February, the spring that was the source of life to us ceased to flow, the rains were months overdue and the island was strewn with the carcasses of the animals that the drought had killed and then in quick succession, a series of events happened that would claim the lives of several of these settlers and the first one was that the Baroness and Philipsen disappeared, were never seen again and the rumor was that they were murdered. Everyone was a suspect because she had made enemies with everyone on the island but the prime suspect was the recently jilted lover Lorenz in a menage a twa gone bad so he was very interested in getting off the island quickly and he booked passage to Guayaquil in July 1934 but he was shipwrecked and found four months later dead on the beach of a nearby island where he had died of thirst in the drought and then finally Friedrich and Dore were vegetarians, their garden had failed in this extreme drought and so they were driven in desperation to eat meat in this case it was a bad choice because the meat was spoiled and Friedrich died after a couple of days from botulism so most of this is known but what's not known and we have the advantage of the 2020 hindsight from 50 years of research on El Nino and the Southern Oscillation is that the drought was caused by La Nina and so is a year-to-year fluctuation of the climate system that originates in the tropical Pacific through interactions between the ocean and the atmosphere we refer to the warm state as El Nino and the cold state as La Nina so how does La Nina affect the Galapagos? that's shown here and you can see in the middle, upper panel it's a global fingerprint of La Nina impacts for December, January, February this is the typical season of maximum and so event development it's very dry in the Galapagos during this season and the reason is simple is there a point around this? how do I do that? oh there it is, yeah there's a rain band that sits north of the equator it's called the intertropical convergence zone it's where the southeast trades and northeast trades collide usually sits north of the equator except at the beginning of the year it migrates southward as the equatorial band warms up this happens regularly every year except in those years when there's a La Nina because the equator stays cold and that keeps the rain band situated north of the equator so a common index that we use to characterize Enso variability is Nino 3.4 it's a large aerial index in the central Pacific where the atmosphere is particularly sensitive to the underlying ocean conditions here's a record that starts in 1900 and goes to the present and if we just blow up the period of interest here from the 1930s this is the timeline of events that I just described on the bottom and you see that Doran Friedrich arrived in late 1929 during a warm period warm means wet in the Galapagos good for gardening so they started out well but then the tropical Pacific drifted into a cold state and here during this La Nina of 1933-34 is when Doran first recorded in her memoir The Drought if we look at a reanalysis a 20th century reanalysis we can make maps of the sea surface temperature field here you can see it's cold all the way from the coast of South America out to pass the international date line the precipitation for this month this is January, February, March, 1934 dry all along the equator and in particular at the longitude of the Galapagos here's time longitude plot this is longitude along the equator time runs up from 1929 to 1935 here's the 1930-31 El Nino and you can see that after this El Nino conditions became colder and they reached the peak in 1933-34 but in the eastern equatorial Pacific the following year was also cold 1934-35 so they ran into an extended period of cold and dry conditions now the while this event was unfolding in the Galapagos there was a disaster of even more monumental proportions developing a few thousand miles away and this was the great plains dust bowl of the United States, the 1930s dust bowl and it was a time of great social upheaval and hardship aggravated by the economic distress of the Great Depression these were not just coincidental events though they were both driven by the same cold sea surface temperatures that we just talked about and we know this actually from modeling studies that were done almost 20 years ago that when you have a cold tropical Pacific you have a dry large portions of the United States become dry and in fact 1934 was identified as the worst North American drought year in the past millennium this year being the year that all these plans on the Galapagos suddenly unraveled now the reason this is relevant today is that we are now in a period of extended La Nina conditions that's the blue line here and the time 2020, 21, 22 and into 23 La Nina's often come in Paris we saw that in the 1930s but you can see this if you make an average of 10 La Nina's over the past 50 or 60 years what's interesting about this event April 2022 is the coldest April on record coldest April since 1950 and there's a good chance that this event will continue for the rest of the year and into early 2023 and this is bad news for the US in particular maybe other parts of the world as well the western half of the United States has been in drought for the past two years severe to extreme drought because of this extended La Nina on top of warming and drying trends driven by climate change and if this La Nina continues on there'll be no relief in sight at least in the near term and this is going to be a serious concern for the growing water crisis in the western US and the potential for another extreme wildfire season and with that I will end and thank you thank you Michael for your presentation we now move to our last presentation for the day which is from both Selga and her PI Francis good morning everyone from Dublin I'll just share my screen with you there we are we seeing that yeah we can see it thank you yeah great okay so the historical and the religious circumstances of the Jewish revolt against Selukid rule in the 160s BC have been examined minutely over the years it was a pivotal decade for Jewish identity politics which laid the groundwork for the independent kingdom of Judea that followed less than 20 years later midway through the rebellion the regaining of the Jerusalem temple and restoration of the Yahweh cult was commemorated with the very first Hanukkah festival which is still celebrated today but one aspect of this very critical period has hardly received any attention trying to find the correct slide here my apologies there it is there the biblical books of the Maccabees and the accounts of the Roman historian Josephus say that the outcomes of the rebellion were affected by two famines that occurred during the decade the first one is blamed on the coincidence warfare with the sabbatical year that is the year during which the land was to lie untended for religious reasons it is supposed to have forced the surrender of the Jewish rebels at the border fortress of Bethlehem of the newly recovered temple in Jerusalem the explanation is offered for the second famine at all but now with the help of Francis Ludlow and Joe Manning's recent research on volcanism and the effects of eruptions on climate we have some supporting evidence that the conditions at these particular times in Judea were indeed conducive to famine and before I go on and explain the details I'd like to invite my PI the project leader Francis Ludlow to explain our project to you Hello thanks Salga for letting me hi Jack your presentation for a few moments I'm just going to say a few words about what our project is doing in terms of compiling evidence of how we know past eruptions occurred including for the period that Salga is discussing and what contemporary evidence we have from this period to start determining what likely climate impacts they had to inform our study and Salga's study of their potential societal impacts but first how do volcanoes generally impact climate here you'll see on the left the eruption of Mount Pinatubo and the Philippines in 1991 and this is pretty much the largest climatically impactful eruption of the 20th century it reduced global temperatures by a couple of degrees for several years following and it was able to do that by injecting large volumes of sulfur dioxide high into the stratosphere where it oxidized to form sulfate aerosol particles that encircled the globe within a few months and these aerosols happened to be very good at reflecting incoming sunlight back to space and in that way they can induce the cooling on the Earth's surface and you can actually see these aerosols sitting in the stratosphere in the image on the bottom right taken from the space shuttle following the stratosphere in the image just above so next slide please that's okay thank you so despite being very light these aerosols will eventually fall back down to Earth under the influence of gravity and some of that fallout will occur over the great ice sheets of the polar regions and we can in fact measure the level of sulfate that fell onto the ice each year by taking deep ice cores from places like Greenland and then melting and measuring the sulfates in the annual layers of ice so this graph then shows the level of volcanic sulfate measured in the Neem Greenland ice core from the period Selga is discussing and in the 160s we have not one but three major eruptions beginning with the orange bar which shows the sulfate deposition from a tropical eruption that likely exceeded the climate altering potential of the pinot tube on 1991 and this was then followed by three further eruptions shown in the tree sets of red bars with a final event just outside our window of consideration for this presentation in 158 BC so not a pleasant time to be alive probably from a climatic perspective the ice core certainly picked this decade out as likely experiencing greater volcanic climatic instability than anything we've certainly seen in the 20th or 21st century so far next slide please so how do we have any contemporary evidence for the climatic impacts the direct climatic impacts of these eruptions from the broader region that Selga has been discussing well there are many lines of evidence but to the east if we're going to highlight just one in Babylon we have perhaps one of the most remarkable climatic records from the ancient era with daily wetter observations systematically recorded and what are known today as the astronomical diaries and they cover several centuries and you can see them preserved on one of these tablets and when we look at these years we can see multiple reports of severe cold which line up well with our ice core evidence next slide please we also see curious reports that describe things like the disc of the sun looked like that of the moon which we can interpret as volcanic dust veils in which the amount of sunlight coming through the atmosphere is notably reduced and sometimes in this particular manner that past observers when they seen this sort of phenomena often know that as portents are or others there's even more evidence we could present but hopefully this is enough of a taste to confirm the significance of these eruptions and the hypothesis that we would probably likely see some sort of societal response in the region and period Selga is examining okay thank you thank you Francis Selga would you like to continue please can we hear her do you think you need to unmute yourself can we do it for her my apologies I lost the connection and all my no problem we can have you here alright so back to Gidea at last you can see from this slide that Jerusalem the capital and Betzura which was the fortress on the southern border both fell into the zone of the volcanic aerosols which shows that they're at that latitude there was fallout from the volcanic eruptions so that the climate was very very cool the main crop I hate to interrupt you but we can't see your slide if you're sharing a screen you may have to just try to do that again please my apologies you can see it now good to go thank you so the main crops wheat and barley require a high soil moisture for development but followed by higher temperatures to reach maturity for a very short period so development of the crops of 164 BCE would have been most severely impacted by a volcanic eruption in the period when the heat was required for the completion of the growth cycle and the fallout over the following year or even two years would have affected the growth of volunteer crops in the yield of fruit trees that would under normal circumstances have seen the population through the sabbatical year and until the next harvest so although the literary sources were written some time after the events we can now say with confidence that the writers were correct about the famines occurring and when but in the case of the first famine we can also say that the writers were mistaken when they blamed the sabbatical year for the famine and for causing the surrender of the Jewish rebels at Bedsour and the starvation siege in Jerusalem given the new data we would expect that the geographical areas around Judea might also show evidence of famine in this period but the archaeology reveals something different from Galilee in the north down into Samaria along the coast with the Greeks and the Phoenicians had their cities in the transjordan as well as south of Judea in Ijimea there is no great sign of famine or food shortages in fact we see in all of these surrounding areas luxury goods like decorated tablewares and large quantities of heavy amphoras imported from the Ijean and the Mediterranean by contrast Judean assemblages of tablewares were of a plain local type and there were no imported wine amphoras or other imported luxury goods the exception was Jerusalem southeastern hill the city of David where the affluent salute could settlers and Hellenizing locals are thought to have been concentrated so while Judea in general suffered famine as a result of climatic change it seems her neighbors were able to cope by making use of their commercial connections and more diverse economies we might ask why Judea looks to have been more insular than surrounding areas even ones also with a large Jewish population such as Samaria this is an ongoing part of my research but I will mention out just a few suggestions years of struggle to regain the right to live according to traditional Jewish law a freedom that had been removed from them at the beginning of the decade by the Seleucid king seems to have led to a sort of economic segregation understandably there was a reluctance to engage with the Seleucid control trade networks and there are signs that observant Jews were beginning to close ranks some Jewish owned lands were demarcated from those of the Greeks which suggested that they preferred to eat produce grown according to Jewish food laws and there also appears in this period to some tightening of dietary rules so the insularity of the greater part of Judean society together with the coincidence of the sabbatical year in the case of 163 BCE seems to have exacerbated the famine conditions meanwhile without these hindrances surrounding communities were better able to manage and deal with the upheavals of the 160s to summarize climate forcing resulting from volcanic eruptions in 168, 164 and 161 corroborates the literary accounts describing famines in Judea in 163 and 161 events that affected the course of the Maccabean revolt against the Seleucid rule. With the new evidence we can reassess the statements in the literary accounts that the sabbatical year the Shemetah was principally to blame for the 163 famine and its consequences for the sieges at Betsu and Jerusalem. And for the first time we can suggest an at least partial explanation for the 161 BCE famine. As a result of this new perspective we can hypothesize about the exposure of Judea to famine when surrounding areas seemed to have escaped suffering. We might posit that owing to the struggle to regain the right to live according to traditional Jewish law a tendency toward insularity heightened Judea's vulnerability to climatic shocks to food supplies in contrast to its neighbors who are more open to outside influences and prepared to rely on those channels to mitigate the effects of food production failures and shortages. Thank you Selga I'm assuming that you are done with your presentation sorry we can't hear you again Yes thank you Julian Okay thank you great Alright thank you to all of our speakers for transporting us to the past with those very insightful presentations we now move to the last part of our press conference which is the question and answer round I invite questions from journalists both in the room and online just to recap if you're in the room and if you have a question please raise your hand and I will hand over the mic to you if you are joining us virtually you can type your question in the chat or use the hand raising function on zoom and we will call up to you for your question Hi I've got a small question from Michael the subject you presented was really interesting so my question would be how did you get interested on this particular story how did you end up with this Thank you for that question I was at a conference about five years ago and we were at a friend's house and having dinner and drinks and she says she was my co-author I should acknowledge her Christine Karen Paridou from University of Hawaii and so we were having a conversation she said you know I saw this video on TV last night and it was about the Galapagos and drought and they never said a word about ENSO and it's obvious what the cause of this drought has to be and so I watched it and there's a few books there's a memoir and there's a couple others and we read them and decided we've got to write a paper about this and so actually our paper has been submitted a couple of weeks ago to the Bolton American Meteorological Society it's been tremendous fun working on this project because in a short presentation like this I've not been able to make all the connections that we made but it's really a rich history and one that's still very relevant today so it's been a lot of fun serendipitous when scientists get together and start talking sparks start to fly and this was one of those occasions thank you I can't wait to read your paper then right thank you do we have any questions coming in online or do we have a question in the room okay we have a question I'm just going to hand over the mic to you yeah I just have a question to Francesca Casale I was just wondering whether you have considered regarding the Nile watershed discharge and the effects of climate change whether you have considered the effects of damming on the river because it's currently a big issue the filling of the Grand Isopian Renaissance Dam it's currently being filled and there's more I mean there's dams already in operation and more of a plan so this is going to be perhaps even a stronger issue or even more important at least regarding discharge or what availability for the downstream in the future yes today I report some the results of the natural flow so the natural discharge so we in this moment for this kind of results that I report we didn't consider the artificial part so for example dams and other also and for example the agriculture and irrigation part of discharge but for example in the last slide I report a reference of a previous study where we have done the study about the Ger Dam in Ethiopia because our hydrological model could be adapted to consider also dams and the regulation of water discharge we are doing two different study if you want one is on the natural flow because for climate projections is useful to know which is the natural discharge the natural flow and then after when we know the amount of water available water we can decide how to manage it and for example the amount of water that we can use for irrigation or for dams and so on in parallel we are considering the for example the regulation and the irrigation so we are developing and we are studying the hydrological model to consider also for example the Ger Dam or the Aswan Dam and the contribution of irrigation so today I report only the natural flow to have the comparison between future, present and past because obviously some dams was not present and also in the period that I consider as reference because in 1970 we had different dams than in the present so in the 2020 but we can consider and we are considering also the regulation of dams and irrigation so but it's a different projections. Thank you Francesca do we have any additional questions? Right okay so if we have no more questions this would be the close of our press briefing thank you so much for joining us today if you find yourself struggling to connect with speakers for interviews or comments after today's press conference you can just drop me an email at media at egu.eu we have some more fun and exciting press conferences lined up both today and the day after so be sure to visit the media.egu.eu for more information thank you once again