 Hello everyone from wherever you're joining. Thank you for being here today for this NCAR Explorer Series lecture streaming live from our homes to yours. My name is Dr. Dan Zietlo and I work in education and outreach here at the National Center for Atmospheric Research or NCAR which is a world-leading organization dedicated to understanding Earth's system science and that includes our atmosphere, our weather, climate, the sun, and the importance of all of these systems to our society. I'm really excited to be here with y'all today as we learn more about our changing extreme weather with Dr. James Doan. So for this Explorer Series event we'll be taking questions at the end of the lecture but definitely submit any questions you have during the talk through the Slido platform. Dr. Doan also has a couple poll questions for y'all to answer throughout the talk which can be found on Slido as well. So to find Slido and join if you scroll down this webpage just a little bit you can see the Slido window just below where you are seeing the live stream video of this event. Also be sure to add your thoughts to our work lab question what is something you think of when you hear extreme weather because we're going to get to that very soon. This lecture is also being recorded and will be available on the NCAR Explorer Series website. So today we are joined by Dr. James Doan from NCAR's Mesoscale and Microscale Meteorology Lab or simply MQ. Dr. Doan received his PhD in meteorology from the University of Reading in the UK and has been with NCAR now for 16 years. He's currently a senior Willis Fellow and Deputy Director of the Capacity Center for Climate and Weather Extremes at MQ. Dr. Doan works with stakeholders from the energy, water and insurance sectors to understand our changing extreme weather and climate events as well as their impacts. He has done work on assessing future hurricane impacts on the offshore energy industry as well as exploring the value of multi-year climate predictions for water resource and food risk management. So with that let's welcome Dr. James Doan. James how are you doing today? Thanks Doan. Yeah doing great. Yeah welcome everyone it's great to be with you all today. I look forward to discussing extreme weather and what what we can do about it. Awesome and before we go much further James let's go ahead and see what our audience is thinking about extreme weather. So Paul or Brett would you be able to share that word clap with us and as we wait for that to come up James what do you think about when you hear extreme weather? I'm always in awe of just the structure and the scale of it and just the power. So I'm fascinated to understand what drives extreme weather. You know the physical processes that create these structures that just have such a large impact on society. Yeah definitely. Great so looking at some of our audience answers the big one I see is climate change. So we got a number of people thinking about climate change. Danger, chaos, impactful, stay home, property damage. Very hot or very cold too much or too little rain, abnormally strong weather, whether that is damaging, droughts, floods, global warming, tornadoes, hurricanes, unusual. I think that yeah so I'm seeing a lot of themes here about you know what's basically happening within climate change. It's great. I think that's a perfect setup for for what we're going to learn today from you right James? Exactly and look at that right in the middle of front and center climate change so and this is exactly what we're going to be discussing today how our extreme weather is changing and actually I noticed a lot a lot of those words could be categorized in as either the hazard so the wind or the rain and the impact. So I saw property damage and impact so we're going to be talking about both of those today so I'm glad we're all on the same page there. So yeah I'll get started here. Great, looking forward to it. So yeah welcome again everyone and I'm pleased that this is going to be interactive so please as you're thinking and listening please type in your questions to the Slido just below this live stream and also remember to contribute to the online polls because I'll be returning to those in a few minutes. So I'm going to make the case today that we're in a new era of extreme weather impacts so I'm going to talk about how extreme weather has already changed and how we think it might continue to change in the future. I'll say a bit about how we how we know things might change in the future and also I'm going to showcase a few projects where I have been working with the insurance industry to really align the the science discoveries we're making with societal benefit. So yeah let's get started. So I wanted to start with a bit of background about myself so I'm a weather nerd. Here I am standing in some weather. This is accumulated small hail a couple of years ago just outside the Foothills Lab in Boulder Colorado. I've always been fascinated by the weather and that's what drove me to study atmospheric science at the University of Reading in the United Kingdom and then following my education I was lucky enough to get a position at NCAR. So NCAR is such a great place to work it's full of ambitious people and great facilities and freedom of scientific endeavours. I'm also lucky enough to be connected to what's called the Willis Research Network so Willis Towers Watson are a global reinsurance company more on that later and it's in their interest to know about extreme weather risk and to protect us from it so I'll say a lot more about that in the next hour. I wanted to go back even further in time and just talk about some of my early influences. So I grew up in the UK so I was an avid viewer of the BBC weather forecast. So I grew up where that number three is three degrees Celsius there in northern England. So this guy in particular, Rob McKellway, whenever he gave the weather forecast he threw in like a science tidbit and so I was always fascinated by these scientific insights that he threw into the weather forecast and in particular what amazed me was that when we look up in the sky we see clouds thunderstorms we actually have mathematical equations that describe this system so it's amazing to me that we can we can describe our weather systems through maths and physics. Another influence of mine was in my hometown of York in northeast England we had our own extreme weather and that is severe floods. So here's a local pub and this is a particularly severe flood a few years ago and the flood almost rose to completely submerge the lower story. Now the interesting thing this pub is hundreds of years old as you might guess and they mark on the wall whenever there's a flood and you can guess that the most recent floods are right at the top. So there's something happening here. I wanted to give a quick overview of NCAR just to say why we exist. So we conduct fundamental research into the earth system. We also support the research community so we have the latest weather and climate models we have the latest observational facilities and we also have a strong education program. We also extend scientific discoveries to society so I'll be showcasing that today and that is now front and centre of what we do. We also strive for a diverse and inclusive workforce because not only is it the right thing to do but studies have shown that diverse groups of scientists produce the strongest and most impactful science and just talking of our science we do produce the highest quality of science. So this is a ranking table of a measure of the quality of our science so you might know that scientists publish their results in scientific journals and other scientists refer to them. So this number here on the right is an average number of times the other scientists refer to NCAR published work and we're right at the top of the league. We even beat the Ivy League schools. This is about five years old now from US News and World Report so it would be interesting to see an update. So not only do we produce the highest quality of science we also produce the most widely used technology. So in particular our weather simulation model is used in many countries around the world and here's a time series this graph here of the number it's a measure of the number of users of our modelling system so you can see it's going up over time. Now I would argue that there's room for another metric here and that is of our impact in terms of how usable our science is and how it's used and how it benefits societal decisions. So I expect we'll see more of that going forward. Now I'd just like to take a pause here and just remind you all that there are some polls coming up so I hope you've had time to scroll down and fill in the polls. So I'd like to say a bit more about our facilities at NCAR before I launch into weather extremes. So we have one of the Gulfstream 5 aircraft that's been retrofitted for scientific research. So the nice thing about this aircraft it can fly very high above all our weather systems and look down on them and observe them. Not only that it has about 11,000 kilometer range so we can really conduct global studies into say atmospheric constituents and pollution and circulation. We not only have aircraft we have satellites so this constellation of satellites was launched in the past couple of years called Cosmic 2. So there's a few of these in orbit and they all talk to each other and they give us thermal profiles throughout the atmosphere and humidity profiles. So this new data is actually improving our ability to forecast say hurricanes. So the final facility I wanted to mention is our supercomputers. So this is one of the fastest in the world. This is up in Cheyenne, Wyoming and in fact the machine itself is called Cheyenne. Here's an image of it here and we need this high computational power to run our complex weather and climate models as depicted here. So this machine here is the equivalent to about 145,000 desktops plugged together. Now this is a few years old now and we're lucky enough to be getting a new machine. There was actually many named by a school student in Riverton, Wyoming and it's going to be called DeRatio. So DeRatio is the Spanish term for straightforward and it's a name given for a forward moving thunderstorm system and that's one of the systems we'll be studying on the next generation machine. And this new machine that's coming online later this year has the capacity to calculate about 20 quad, yeah quadrillion calculations per second. So that's a million trillion calculations per second. So we should be able to do some great science for this horsepower. Okay so now I'm going to switch over to our first poll question. I wanted to get your take on what do climate scientists such as myself actually do all day. I've said a bit about what NCAR does but what do I do? And let's see the responses. Disappointed to see snack didn't get any hits. That's what I've been doing all day. But great. I think it's stable. I think you've all settled on all of it. So yes we run weather and climate simulations on supercomputers. We collect observations. There's many other things we do but these are some of the most important. We snack and we discuss science with non-scientists and that's one of the key themes I want to bring out here and it's so critical to align our science and not only does it inspire new scientific directions but it facilitates the science being usable at the same time. Okay so I'll return to my presentation. Okay now I'm going to use the terms weather and climate a lot in the next 45 minutes so let's just define it. We can think of climate as your wardrobe and weather is what you're wearing today. So every day the weather can select from a library of possibilities so just like when you get dressed in the morning you can select from your range of clothes in your wardrobe but we know that climate just like your wardrobe changes. So say you gave some clothes away to Goodwill and bought some new clothes so now the selection of clothes from which you can select has changed. Some old you can no longer wear the old clothes and you've got the new options so just like the weather some old weather types might disappear and some new ones have appeared and this is what we mean by weather and climate and let's also think about some background about what fuels our weather. Well of course it's the sun so the sun is hot it emits radiation. Some of that radiation is observed by the Earth's surface but some is reflected back out to space. Now the Earth itself has a temperature now so it too emits radiation but the Earth has an atmosphere which contains greenhouse gases that absorbs some of that emitted radiation and in fact it sends some of it back down to the surface and this is what keeps us warm this greenhouse effect. So actually greenhouse gases are good without greenhouse gases the average global temperature would be about one Fahrenheit but thanks to the atmosphere current climate is about a global average annual average 58 Fahrenheit. So greenhouse gases are good but too much is bad so this is a time series of global average temperatures over the past 170 years or so so you can see it's been trending upwards over the past 100 years. Now we've known this for over 160 years now so this Irish physicist John Tindall recognized the greenhouse effect and about 40 years later a Swedish physicist actually quantified the warming of the Earth's surface should the concentration of carbon dioxide double and in fact his quantification of about 9 to 11 Fahrenheit is not too far off what we understand it to be today but of course climate has always varied so let's just look at the past 400 000 years of Earth's temperature so the red line here is a measure of Earth's temperature and you can see over the most of this 400 000 year period we've been cold and in fact we've been in ice ages so every 100 000 years or so we've seen these spike warm spikes the interglacial periods and luckily for us we're in one right now. Now the blue line is the concentration of carbon dioxide so just look how closely they co-vary and now look on the right where our carbon dioxide concentration is and I just checked yesterday the concentration of carbon dioxide in parts per million yesterday was 419 so we're way up on the on the right hand scale there so what do you think the red line is going to do yeah sure enough some of you might be familiar with these climate stripes so this was a great climate visualization and communication tool developed by Ed Hawkins at my old university the University of Reading so this is a time series from 1895 to 2019 at the average US temperature so blue colors indicate cool temperatures red colors indicate hot temperatures so on the whole you see a transition from cooler on the left to warmer on the right but on top of that we've got you know red bars in the distant past and blue bars recently so that's climate variability but if you blur your eyes you can see there's a long-term trend towards warming temperatures and these warmer atmosphere can hold larger amounts of moisture so today's extreme weather is operating in a very different atmosphere than it was even 30 years ago so it's really inconceivable that these weather systems have not already changed and in fact these climate stripes have gone viral this person even kitted out their Tesla with stripes I'm not sure I'd do that but I don't have a Tesla so and in fact it was show your stripes day two days ago so if you follow that hashtag hashtag show your stripes you can see what other people have done with these stripes it's even the people have knitted their own scarves and spices anyway we've had our our own recent extreme event last weekend where many temperatures were smashed across the US West and a lot of people were talking about the daytime highs but what I found most remarkable was the was the hot nights and in fact Death Valley recorded its hottest night ever with a morning minimum of a toasty 104 Fahrenheit unbelievable and of course those temperatures are really exacerbating the current drought right across the west there's an image of Lake Oroville so the hotter air is really thirsty it sucks more moisture out of the surface and and standing water and in fact Lake Oroville is about almost 200 feet lower than it was two years ago this month okay well let's have a look at a times time history of the numbers of damaging extreme events so this is compiled by a reinsurance company and we're looking at a 40 year history going back to 1980 so the line on the top the orange line is for all types of disasters and you can see the numbers have about doubled in the past 40 years and that will just concentrate on the top line that is largely due to weather and climate events things like earthquakes have stayed stayed about flat and along with that we've seen increasing losses and the so this is a time history again of 40 years of global total losses in newest billions of dollars adjusted to 2019 value values so the blue line is the total losses the red line is the portion that was insured and so you can see today's losses are about four times what they were back in the early 1980s and that's largely because there's more of us and we have more stuff there's more expensive assets in harm's way but also there's a climate change component here so again i just wanted to take a pause here and remind you all to scroll down and fill in the next poll if that's coming up soon so these disasters are becoming increasingly costly let's zoom in now on the u.s to see where the most costly disasters are so the the darker the color the higher the total losses and this is 40 year total losses so you can see texas louisiana florida standout the gulf coast states but also california and maybe north carolina and new york so yes a lot of this is driven by the high population in these regions but they're also regions that experience severe weather so then this brings us on to the second poll i wanted to get your take on what type of extreme weather is the most costly so let's uh let's see what you all think thanks paul okay the number seems stable there's a clear winner flooding and then a tie for second place between tropical cyclone and the hotx hot and dry extremes drought and wildfire thunderstorms and windstorms they don't don't really register good so we'll we'll keep that in mind i'm going to tell you what the numbers show now so let me uh return to my slides okay so we think flooding is number one so let's see what the nationals center for environmental information tell us so i'm starting with the the least costly first so you are correct the winter storm and freeze is indeed the least costly the 40 year totals in current dollars is between 70 150 billion us dollars next up is actually flooding so between 100 and 200 billion dollars of course where a lot of us live on the front range of colorado flooding is probably the biggest uh risk um we are exposed to large hail but flooding is the big one here um and actually i think under climate changes we'll discuss later the proportion of losses due to flooding may overtake these next ones i'm going to introduce so the next one is severe thunderstorms this includes severe thunderstorm winds tornado large hail and flash flooding so that's estimated to be at least 250 billion dollars the next one is actually drought and wildfire at between 350 and at least 450 billion dollars and top of the list is tropical cyclone so this includes hurricanes and the estimates are at least one trillion dollars over the past 40 years so this gives us a total of almost two trillion dollars of losses over the past 40 years so clearly extreme weather has a huge economic impact and uh we have opportunities here to mitigate much of these losses so i'm going to move on to the world of insurance now and a bit later in the talk so it's remarkable to me that over half of these losses are uninsured so let's see the breakdown by continent so australia has just over half of its total losses are insured the us including the caribbean has under half of losses are insured and that number reduces for the other continent and much of the uninsured losses are taken up by governments or they're just written off so i think we have an opportunity here to develop some more robust risk management strategy for the this uninsured portion okay so hopefully we take a breather now hopefully i've motivated that we're in a new era of extreme weather impacts so the extreme weather itself has changed and so have we this figure illustrates that concept nicely this is hurricane laura last year in the Gulf of Mexico so laura was different than it otherwise would have been if it if it um occurred 30 years ago but also our population has increased and we're increasingly living on in the vulnerable coast now into climate change until we can think of climate change as a pervasive and growing risk multiplier so of course the risk was or risk of extreme weather was already there we can think of climate change as compounding that risk and it's ever present and ever growing so now i'd like to talk about what we changes we've seen already and what we expect to see in the future but before i do so i'd like to say a bit about how we know some of these things so anchor is a world leader at simulating future weather and climate so let me just explain briefly how we do that so i'm interested at the beginning of the talk we have mathematical equations to describe things like clouds winds snowpack stream blow ocean currents and then we tile the earth and its atmosphere and in each tile we have these equations and each tile talks to each other and we take a snapshot outside the window of what's going on feed it to these equations and then run the whole thing forwards in time and it then tells us what the state of the weather is going to be one hour from now one day from now and then out 10 years from now or 100 years from now and of course this is very expensive and that's why we need our supercomputers up there in wyoming now if we make these tiles small enough then we can simulate extreme weather and so this is remarkable this is a visualization of a simulated hurricane so it looks just like the real thing and this is purely from math that's what amazes me so we can track these things count them and we can look at how they're changing over time are they getting bigger are they moving faster and so what are these simulations telling us so let's first think about how hurricanes have already changed so this is an analysis of some of those simulations but also an analysis of the observed historical hurricanes so i mentioned earlier that the environments within which hurricanes occur have changed so the oceans are warmer the oceans are higher and the atmosphere is warmer and more moist now most scientists will agree that climate change has contributed to higher storm surge heavier rain rates and also an increasing fraction of major hurricanes so that means that every hurricane that comes along today is more likely to be a strong hurricane than it was say in the 1970s now we've detected many more changes in hurricanes but we don't have enough data yet to attribute those changes to climate change so scientists are busy trying to pin down some of these other other changes we've detected so how about looking into the future well indeed our science theory and simulations tell us that future changes expected so we fully expect that the rising seas will compound storm surge we fully expect that rainfall will become more intense now we're less confident that it's more likely than not that we'll see a modest increase in average wind speeds of hurricanes and it's more likely than not that we'll see an increasing proportion of these strongest storms so that's a continuation of the observed trend we also have some evidence that the hurricanes will be larger in terms of the area and damaging winds evidence that a pole would shift in the location of peak strength so the storms will attain become strongest at higher latitudes this is particularly alarming prospect for locations like new york and tokyo and we have some evidence for a slowdown in forward speed so there's instead of coming ashore rapidly they'll crawl ashore so this is another alarming prospect because locations will therefore experience damaging winds for longer and the rainfall will be heavier so we expect some quite significant changes so we're going to move on to our final poll so I wanted to get your take on how many tropical cyclones are there around the world every year so let's see what you all think very nice you've all hit on the correct answer 90 that's great I guess my next question be all is why is it 90 and in fact if you were to ask scientists that question why is it 90 not many of them would be able to give you an answer in fact we don't really know why there's 90 we have various theories but one hasn't really risen to the top and perhaps related to that we're not entirely sure whether we'll see more or fewer hurricanes in the future so the balance of evidence suggests there'll be fewer in the future but a number of robust studies point to more hurricanes in the future so really we need to solve this problem and to do so we need everyone around the table so I'd encourage anyone to become a scientist there's power in numbers okay well I just wanted to just review some of these changes again and try to understand why we're seeing these changes so I talked about heavier rainfall in the future and just to give the example of Houston so Houston is no stranger to extreme rainfall and in fact the city of Houston recently quadrupled its risk from extreme rainfall this is largely due to Harvey and other associated tropical cyclones so why is that well these mathematical equations they tell us that that every degree Fahrenheit warming we can expect a four percent increase in the rain rate and this is a fundamental scientific principle that we can really tie it a lot about understanding to so we're very very confident in this change what about stronger winds well here's a an example of the devastation brought by Hurricane Michael in 2018 to Mexico Beach in the Florida Panhevil some of this devastation was caused by water but a lot was caused by winds so why are these winds increasing well we heard that the oceans are warming and hurricanes get their energy from the ocean and so it follows that the hurricanes themselves are the wind speeds are becoming faster and how about a storm surge this is an image during sandy in 2012 what we would do indeed expect higher storm surge partly because the seas are higher that's due to melting of land ice and the fact oceans are warmer and warmer water occupies a greater volume but also because the wind speeds are increasing so the winds actually push the water and pile it up ashore okay now i've talked a lot about hurricanes and that's because it's my primary area of expertise but what about other extreme events you might be wondering well let's move on to severe thunderstorms so these are the um the severe events that track across the midwest and primarily the midwest and the the eastern parts and produce tornadoes large hail flash flooding so on the left is climate simulation of thunderstorm tracks and on the right is observations of thunderstorm tracks for a single season so you can see on the whole our model does a good job at capturing this the the pattern of these tracks across the united states and so we can actually run our model for hundreds of years and look at how these tracks are changing so let's see what our model tells us so here's a snapshot of tracks in current climate so each line is an individual thunderstorm and we can zoom in there on the houston region and the tracks are coloured by how intense the rainfall is that's the current climate compare that to the end of this century see the density of tracks is much much greater so there's more thunderstorms and they're darker so they're more intense and in fact we're seeing four times the number of strong storms at the end of the century than we currently get today Antonio we're seeing more of them and they're becoming more intense but they're getting larger so thanks to andreas prine in uh enkar for sharing his work today so here's a a typical thunderstorm in current climate and here's the the same typical thunderstorm in future climate as per our model so it's more intense in fact the intensity goes up by 30 percent it's also larger so the area of intense rainfall increases by 88 percent and so that means that the total water volume coming out of these systems more than doubles now these storms are huge systems with their so-called organised uh convective systems so let me overlay the boroughs of new york just to give you an idea the scale of these things so they would impact multiple catchments simultaneously um in ways that we haven't experienced before the problem with that of course is that a lot of our in existing infrastructure is very old so thanks to my colleague Tanya Lopez Cantu at CMU for sharing this comparison photo of downtown Pittsburgh it's the same street corner 100 years apart so you can see a lot has changed the thing that hasn't changed is the stormwater infrastructure so clearly a case could be made but increasing the flow capacity of these these drainage systems and in fact my conversations with the um mile high um flood control district here in the front range indicates that um we're fairly well positioned here in the front range we're in good hands so uh we can take comfort in them okay well let's think about winter storms so we can see studies have shown that we expect bigger snow storms in a warmer world rather paradoxically in a warming world we still get snow storms of course and perhaps few of them of them overall but the ones that do occur occur in a much warmer sorry warmer and more moist atmosphere so these storms are more juicy they have more more moisture to snow out and then we move on to hot and dry extremes so many of you in the front range will have woken up to a sunrise uh peered through some smoke and already this year's fire season seemed to have kicked off to an early start I think over half of our firefighting resources are currently engaged which is fairly alarming so early in the year and last year of course California had the devastating fire season Siberia had unprecedented intensity and aerial coverage of fires in 2020 then of course Australia in the 2019-2020 that summer had the devastating fire season so this warmer world we live in is more thirsty the the air is sucking the land so this dry creating tender dry fuels a lot drier than otherwise would have happened 30 years ago so just continuing on the theme of wildfire and focusing in on California this study showed that the number of extreme fire weather days has doubled compared to say the early 1980s that's shown in this paper here so that's due to due to the temperatures rising and due to shifts in the precipitation distribution so other studies have shown that the rains in California arriving later in the fall so this extends the duration of the fire season and of course you probably read in the news that there's been severe impacts of these these new fire seasons the local power company PG&E introduced a policy of de-energizing the power lines in advance of severe fire weather so when there's a strong wind Santa Ana event they basically shut the power off so this study here looked at the risk of power shutdowns in current climate and future climate so let me tell you what you're looking at here so up the on the left side we're looking at the numbers of people impacted and the black line is from all lines the gray bars are from high voltage lines the two lines on the left are for what we can think of as current climate the two powers on the right for dry autumns consistent with what we expect from climate change so there's actually the difference between these is about 70 so 70 increase in the people affected by these power shutdowns so clearly I think it's time for a discussion about this power shutdown policy and what what could be done about it and how we can work together to come up with more effective policy that mitigates some of these impacts now that was hot and dry we're going to stick with California and think about wet so we think about California's other big one so of course the big one is quake the other big one is a month-long deluge so thanks to my colleague Daniel Swain for sharing this slide so did you know back in 1862 downtown Sacramento was flooded and people got around on boats and in fact the most of the central valley of California was flooded from a month-long basically continuous rain so can this event happen again for this study here found that yes it can happen again and probably sooner than we expect so this graph here goes from today out to the end of this century and is the cumulative likelihood of this event happening again the dash line is without any effects of climate change the solid line is with climate change so it's a fairly alarming prospect but it's more likely than not we'll see one of these events in the next 40 years according to this study and so that would be disastrous because this other study by wing quantified that there's 763 billion dollars of assets in California's floodplain so this is the disaster waiting to happen okay that was a quick whirlwind tour of what we can expect extreme weather to look like in the future so now I'd like to showcase a couple of examples of how I work with the insurance industry to align the science with societal benefit so let me explain how this works so we have two pillars here the insurance solutions on the left and climate science on the right I work in this green collaborative space where we are transforming climate science and risk management practice so the goal here is for science to be inspired by the needs of risk managers and for risk management practice to be informed by solid science so the great thing for me is that it inspires me to think about climate and extreme weather in ways I would never have imagined alone so it's a really rich process so let me give you a few case studies before I do that let me just tell you why the insurance industry are interested in extreme weather as you might imagine Hurricane Andrew in 1992 it really rocked the insurance world remember this was a category five that went right through Homestead close to downtown Miami and this led to many local insurance companies going bust they couldn't afford the payouts and that's because they were looking at the past history of hurricanes to estimate their risk and they couldn't afford the actual risk that was changing they just didn't know about it so they realized they can no longer look at the past to think about the future and in fact one of my insurance colleagues is famous for saying it's a modelled world so this reflects the fact that we can no longer just use observations the records are too short we can't estimate say the one in 200 year events on a 50-year record so this led to a few private modeling companies springing up the names of which are some of the famous ones are here and so these are so-called catastrophe models and they quantify the risk from extreme events and so I'm part of this Willis Research Network so it's a collaborative between public science such as NCAR and various universities around the world and the world of finance and so we work together to align our latest scientific understanding of extreme weather with insurance solutions with the goal of strengthening societal resilience to extreme events now the first project I'd like to just showcase what I'm calling the NCAR Willis Towers Watson hurricane wind simulator so we developed a new model of the surface windfields of hurricanes and this is what it looks like for the case of Hurricane Maria over Puerto Rico in 2017 so hopefully you can see the outline of the island there the hurricane track in black from the bottom right to the top left and the colors you're looking at the surface wind speed the blues of the strongest winds and the greens of the lightest winds so you can see the winds are strongest over the ocean as you might expect they reduce over the land because the land is high friction but there's some strong winds in land associated with mount tops and the winds decelerate over the urban area of San Juan and that's because urban areas are very rough and they really put the brakes on hurricane winds and actually that's unfortunately why these urban areas are damaged because they absorb a lot of the shock and these winds and so we use this model to develop some scenarios of future hurricanes so let me tell you how we do that so this is an example of how I modified Hurricane Irma in 2017 so you're looking at South Florida hopefully you can see the tip of Florida in the Florida Keys so if you look at the top left panel this is the actual Hurricane Irma again the colors are the surface wind speeds of the hurricane and the black line is the hurricane track from south to north now I modified this hurricane case according to our understanding of climate change so we know the winds are likely to increase in the future so we bumped up the wind speeds for Hurricane Irma in our simulation that's the top middle figure the top right figure we made the winds larger so greater extent the strong winds the bottom left we made the storm make landfall faster so it came in the shore faster and then the bottom middle case is all three of those changes together stronger larger and faster and then the final case is a track shift where we move the track from an east coast landfall to a miami landfall I should caveat that by saying that the faster scenario was more a sensitivity study rather than a climate change expectation so the insurance company then took these winds and plugged them into their loss model and calculated losses to the portfolio of insured properties so let's see what they found so the the stronger scenario in the top middle we found that the losses doubled compared to the actual losses the top right the larger scenario led to just a 10 percent increase in losses the faster scenario in the bottom left increased losses by 20 percent all three together stronger larger and faster caused losses 2.5 times what actual losses were and maybe not surprising if we shift the track to miami the losses tripled and so the insurance company are very interested in these losses because they want to ensure they have sufficient capital to pay out if these events happen so let me say a bit more about the world of reinsurance and also how how they're using this information now reinsurers their role is to provide insurance to insurance companies so you can imagine a local insurance company in miami if it gets hit by category five again then it may go under so it buys that insurance company buys insurance from the reinsurer now it's just like homeowner's insurance where they have a deductible or what's called retention here so at the left here we have loss from a hurricane event and so if the losses only extended up to 10 million dollars in this idealized scenario that is all retained by the insurer but the insurer has options then to buy coverage should the loss exceed 10 million so they can buy coverage in lairs so they can estimate or guess which lairs they're going to be exposed to so if they think they're only going to get a 50 million dollar loss they'll buy coverage in the first three lairs and perhaps not buy coverage in the final lair so the reinsurer then or Willis Towers Watson are very interested in these climate change scenarios and which lairs the climate change scenario will push them into because they need to make sure they can have adequate capital to cover these losses should they occur and so that's what they plug those losses and calculate did how far they extend so that was an overview of one project let me just give you one more and this is the final one and that is where we looked at building codes so how effective are they actually against hurricane winds they're designed to be effective but can we quantify it so again this was motivated by recent hurricanes in Florida ever since the 2004 season interestingly Florida implemented a new very strict building code in about 2002 and that's what we're testing here the second question we ask is it cost effective so is it effective economic policy so let's see what we did here so we were lucky enough to get our hands on some lost data from these seven hurricanes that occurred in 2004 2005 so the colors here indicate total losses for these seven events the reds are the color they're higher the loss so you can see the entire state is covered in losses in fact we had a total of 5.2 billion dollars in insured losses in this data set let's have a look at how these losses vary by hurricane let's compare Charlie and Francis both impacted Florida in the same year the damage pattern was very different so Charlie was in a category four intense storm but very small so a lot of the losses although they were high they were confined close to the track Francis on the other hand was on a very large storm covered the entire state so the losses spread much more broadly but the peak losses were lower so it matters what hurricane you're talking about when it comes to losses so we combine these lost data with our wind data to really quantify the effect of these building codes and we actually found that yes indeed the Florida building code is effective against hurricane winds and it was remarkable to me that we found that if you build the code you can expect your losses to be reduced by 68 percent that was compared to homes not built code so it really is highly effective and in fact we we found that every dollar spent building to code you can expect four dollars back and reduce losses so it really is effective policy and so there's conversations ongoing about how other states might want to emulate the Florida building code other states with less stringent building codes okay well we're nearing the end now so before I leave you I just wanted to highlight what's well what's what's coming in climate science well there's a lot the one thing I want to focus on that I'm most excited about is the fact that extreme events know about each other so just look at this satellite image of three hurricanes near the near the Gulf of Mexico and then the Caribbean so clearly they're connected somehow they're not occurring randomly and that might be connected to our common driver which is the warm ocean they're much like buses you can wait forever and then they all show up at once and that's actually quite important because the impacts of these groupings or clusters of extreme events often exceed the sum total of individual losses from individual events so we really need to be aware of these groupings of events and the other question that we're trying to answer is whether the fact they're coming groups make them more predictable so are we able to better forecast these events because they're connected together so I think that's going to be exciting in the next couple of years okay my final point is that Congress is engaged in this topic so I was lucky enough to be invited to testify before Congress specifically the House Committee on Science, Space and Technology back in September 2019 where I talked about extreme events and climate change just like I did today and I made the case that these partnerships between scientists and different societal sectors are essential to really drive the science forward and make it aligned and useful and usable by people who stand to benefit from it that brings me to the end now so that was a whirlwind tour of extreme weather hopefully I made the case that we're in a new era of extreme weather impacts we can think of climate change as a pervasive and growing risk multiplier the good thing is we know we know what to do about it and really one effective way that hopefully I've articulated today is this deep integration of science and risk management across various sectors not just insurance but across the whole multitude of sectors is set to really revolutionize our resilience and our ability to confront climate risk so thank you all for listening I hope that's triggered some thoughts and some questions and I'll hand back to Dan thank you very much yeah thank you so much James for you know sharing all your knowledge with us this is to me is super interesting so I'm sure everybody out there also thought it was super interesting as well especially this idea about how extreme events know each other and how I mean that's something that I think scientists internal are super interested in studying is the interconnectedness of all of these different systems you know cool so let's let's dive into the questions actually we have a number of questions already so let's just stop with start with the top rate of one right now from Anarelli and Anarelli is asking you know we've talked a lot about hurricanes and floods and wildfires is there a place on earth that is at the least at risk from climate change impacts that's a great question so whenever I think of climate change impacts I always go go first to temperature because that's what we understand most so obviously the whole earth is warming some parts are warming faster than others so we know the polar regions are warming a lot faster than equatorial regions and I think the region if I had to give an answer I mean nowhere is completely free but areas that might be least impacted from change are probably somewhere in the middle of the open oceans away from hurricanes such as in the South Atlantic or the I'll leave it there yeah great question I'm sure someone could answer that better than I did that's a complicated question too great so the next question is from Joel who's asking how do you think climate change is impacting severe weather outbreaks in the US my anecdotal observation is that we seem to be getting fewer of these events yeah that's an interesting one so the study I've presented indicated we may expect more in the future so I'm thinking severe weather outbreaks has in severe thunderstorms which is you know summertime thunderstorms in the mid in the midwest for example and on the whole climate change is shifting our daily weather patterns from more sort of benign weather to extreme so perhaps paradox paradoxically we can expect more severe weather interspersed by longer periods of benign weather so in that sense there may be fewer episodes of events but when they do come along they're likely to be more intense and that statement is true across the multitude of extreme weather phenomena so I think that's very interesting fundamental principle there's a lot more I could say about severe weather systems but I'll leave it for now great thank you so the next question from Curious I may loop in with a similar question for their down that you may or may not have the expertise to answer since you don't physically do the insurance side of things but Curious is interested to know about you know maybe you provide some insight on what you see maybe insurance companies doing in terms of like would they increase rates or would they kind of use these different clauses like active God to maybe limit the coverage that they could distribute from some of these events you know great question I think the interesting thing is if insurance companies get nervous and they don't understand enough about the risk they just pull out if they're regulatory if they're allowed to by regulators for example the northeast u.s experiences so I'm talking like buster and then new york they experience hurricanes very rarely we don't really understand the true risk in that region because there's been so few of them and so a lot of companies are very reluctant to take on exposure in that region so they just pull out the another thing I can add is and flood insurance in the u.s so historically and today it's covered by the federal government but a lot of private insurance companies very interested in in understanding their role in strengthening our resilience to flood and so there's a lot of studies going on to better understand our flood risk um so yeah I'm not sure about the act of God but my experience it has they only they only sell insurance when they're sure they have the capital to cover it and that's that that's a role for science to really understand the true risk great and our next question is from Anarelli who's interested in knowing what is a weather phenomena that you first experienced when you moved to the u.s from the uk I have a funny story on that one when I first moved to the u.s moved to boulder colorado we got nine inches of snow I was supposed to go to my friend's house and so I called up and say oh I guess we'll have to reschedule and he's at what why do you have to reschedule there's nine inches of snow on the ground so uh extreme actually this is an important point extreme weather is all relative so if if we had even two inches of snow in the uk the you know cars grind through a hole there's days off school and so the impacts of extreme weather more relate to the rarity of it than the absolute magnitude and so there's a lot of work going on to understand rarity and how that's changing compared to the absolute magnitude so great question and the next question is also from Anarelli and they're giving us this this question about you know how we talk about climate change almost so so when can we stop referring to climate change as a future thing so yeah exactly I can jump in there I fully agree that you know the the days are over when we can talk about climate change is happening in the future a portion of it has already happened so hopefully I made the case today absolutely the future is already here and it started 30 to 70 years ago so yes we can stop stop referring to that to that right now we've seen it we see it in our models we've seen it in observations and yeah multiple viewpoints multiple ways of knowing points to the factors the portion has already happened great and our next question is from Michael are El Niño and La Niña patterns changing with the other climate changes that's a great great question yeah so El Niño and La Niña are examples of climate variability so this is the the sloshing back and forth of warm water across the equatorial pacific that happens on timescales of say two or three years of course the El Niño and La Niña doesn't operate independent of the climate system and studies have indicated that the the characteristics of El Niño and La Niña may change in the future it's too early to say I think whether they've changed already I'd like to see longer data records that we can obtain through our weather simulations to see whether they've changed already but I think I would argue that we would expect some changes given that then they're intertwined with the mean climate yes great and our next question is from Debbie and I think it's referring to the thunderstorm the simulator thunderstorm tracks from an earlier slide but did the thunderstorm simulations include the western united states absolutely I think the tracks tracks I showed today were the strongest storms which primarily occur in the eastern us but oh indeed the western us in fact we were just talking that talking about that today these severe storms operate over the southwest us associated with the the monsoon system so yes and not just the western us you know they operate globally there's a a few large research projects ongoing at NCAR looking at the characteristics of thunderstorms in South America for example I think we have a lot to learn about how these systems are different in the US to other regions in the world what drives them their characteristics and their changes in time great and our next question is from Curious who wants to know what are local governments doing to limit losses in areas where extreme weather are frequently happening yeah I like that I like the framing of that question it's not what are individuals doing it's what the local government's doing and that's spot on I mean there's a large array of community interventions to adapt to extreme weather and to mitigate further changes in extreme weather so take the case of hurricanes for example a few communities around the hurricane prone coasts are really shoring up their wetlands and to make sure they don't lose them because we know the wetlands really acts as a break on hurricane winds they can really drop hurricane categories before they start impacting urban areas so these wetlands are critical so a government at the governmental level they can institute policies to protect wetlands for example another example is to change how we evacuate from hurricanes so making it equitable across society for example people without their own vehicles and just making it a safe thing to do a safe and affordable thing to do so people are protected yeah I'll leave it at yeah thanks for sharing that insight and like you said it's a great point that you know I think of the science mom's initiative for instance where they're really trying to emphasize collective action rather than individual action because that's how we're going to solve some of these issues moving forward for sure exactly yeah I think if the governments make the the climate adaptation and mitigation effective actions the easiest thing to do then that'll it'll naturally follow that we'll be improving our ability to adapt yeah and our next comment is from Stacy and Stacy I just want to say I really appreciate you adding this to the discussion and Stacy says didn't Eunice Newton foot determine CO2 as a greenhouse gas before John Tyndall and I think this is a great example of how we're reckoning in the sciences with you know how we talk about science in the western science tradition and how historically we have marginalized groups within within the sciences and James I saw you you began to respond to me maybe you have some thoughts on that no absolutely I know this is valuable thank you very much Stacy I did not know about Eunice Newton foot so I need to be educated thank you for that thank you for adding and contributing to the discussion yeah I believe there was there was a good article in the New York Times last sometime last year that had talked about how you know Eunice foot had made some of the first observations that you know CO2 could actually be changing the temperature and then that just kind of got lost to history because of structure yeah yeah great thank you yeah so yeah Stacy thank you so much for sharing that with us so moving to a question from Connor a question from Connor excuse me how can emergency managers and insurance companies use the data collected to better prepare for the next big extreme weather event yeah insurance companies always want to understand that historic losses so for example I keep coming back to Hurricane Andrews so you know they suffered severe losses in that event they don't really understand why or they didn't at the time is it due to attributes of the structures they ensure is it due to some vulnerability factors with the infrastructure associated with the infrastructure or do they not understand what they're ensuring very well so there's a lot of uncertainties involved in pricing risk so they're very keen to use as much data as they can get their hands on to understand what drives their risk and how to optimize their portfolios to be resilient so for example particularly when it comes to reinsurance they don't want to put all the eggs in one basket so they wouldn't just ensure Houston they'd want to ensure say Houston and Tokyo with the understanding that it's highly likely both of those cities will not be hit within the same insurance period it might still happen and naturally they're very interested in these connections across basins and across cities they don't want to expose themselves to a risk an unknown risk they're not aware of yeah more data the better great and our next question comes from Jenna who wonders if the warmer air can hold more moisture why is the western u.s in such a massive drought that's a good one yeah I was just thinking the same thing yeah so I write I think they're all in the west yeah I I rightly said that warmer can hold more moisture and that's true but it only can if the moisture is available so what's happening in the western u.s right now is that the surface is I think record dry almost as dry as it ever has been so there's just little moisture for the atmosphere to absorb so not only is it hot it's also very dry and it's also thirsty compared to the amount of moisture it could hold it's holding capacity so yeah once once some of these then droughts kick in it can really lock in hot dry air and very difficult to shift and unfortunately that's what it looks like we're seeing right now when it seems to be extending now to Oregon and Washington it looks like Washington in particular in Oregon Portland Seattle and the interior cities are going to experience record breaking heats this weekend and into early next week so um there's a particularly dangerous situation when it doesn't cool down at night in these regions there we are yeah there's also a you know a social science component too that uh a few people that are studying you know if we have these massive heat waves you know how is that actually affecting the people living in them so our next question is from Jane and it looks like it's a follow-up from the previous question so besides just being in the middle of the Atlantic where where can we live say on this comment I would argue we can we we can live it anywhere um you know we've always lived with the risk of extreme weather and there's always been very severe storms severe hurricanes snow storms floods tornadoes um they're changing we're changing I think we have an opportunity now to change in ways that reduce our exposure to these systems and institute policies that protect us from this severe weather so I think we need to accept that severe weather will still happen they might impact us to some extent but we can we can reduce that impact and bounce bounce back or bounce forwards in a more effective manner so yeah great and our next question comes from Rachel who's wondering what upcoming remote sensing satellite you have to be launched are you most excited about that's a great question I'll start by saying satellite atmospheric science is not my primary area of expertise but I've been excited by the um by these really just the level of detail you can get from satellite information these days so these rapid scans where you get you get an image every minute to say the the eye of a hurricane um unprecedented details you can really see what's going on inside the eye and how it evolves throughout the lifetime of the hurricane and this is important because there's some there's some things we just don't understand about um the drivers of extreme weather and how they behave and so this these new data at the very small scales at which a lot of um impacts occur and that's really where this data is key so I expect we'll learn a lot more about the impactful scales of extreme weather through the this next generation of satellites cool so as we wait for any kind of last minute questions to trickle in I have a question for you um for for any of our students or young scientists that are listening right now who may be interested in you know studying extreme weather or working with insurance companies like what what what some of your advice that you would would give them to start down on that path yeah firstly I think if you're interested in it that's that's the most important thing I think um the challenges are easier if you have an inherent uh long-term interest in them everything gets easier that's that's what I've found that in fact um the job I'm doing now sometimes feels like um a hobby you know I do it because I'm generally genuinely interested and fascinated in understanding how things work so once you've got that uh I think uh things become a lot easier so maybe a bit of practical advice it's important to um to gain experience in to what the world of research looks like so places like ANGAR and other research institutions they often have a very um invigorating and broad visitor program so for example at ANGAR we have opportunities to come and visit uh across different age groups different school levels and university college and upwards uh we have various opportunities to come and visit and actually talk to the scientists and find out what they do and just get get an understanding whether that interests you um so yeah making connections is probably the most important and and we as ANGAR scientists we love to interact with people who have an interest uh we like to talk about our science with anyone so yeah everyone's very welcome awesome and I don't see any other any more questions coming in so with that James thank you so much for being here to chat with us today um and you know it was really great hearing all about the work that you do and learning about kind of our changing extreme weather yeah well thank you and thanks everyone for your input the great questions and uh you all got the correct answers on the poll so thanks very much and I also just want to give a quick shout out to the team behind the scenes so to Paul, Brett, Aliyah and Lorena thank you so much for supporting the event today if you are interested in more ANGAR Explorer series events definitely check out our website for any upcoming lectures and conversations and as well to view recordings of past events so I hope to see y'all next time and have a great rest of your day