hello everybody this is a presentation on the carbon cycle and what is often known as global warming but better stated as climate change this is about section 5 looking at how is global warming linked to food production and consumption so first of all what we have to understand is how is it that our planet is got this really nice atmosphere really nice gentle climate really when it come when you compare it to all other potential planets so looking at this we can see what what uh happens or what's important about this is that we have what's called the normal greenhouse effect the normal greenhouse effect is created by greenhouse gases and the four important ones that we're going to be listing here are carbon dioxide methane water vapor and nitrous oxide these four gases make up the atmosphere and what happens is as the sun's light strikes the atmosphere it warms the planet and then generally a lot of the radiation from the sun escapes the atmosphere but some of it is insulated and kind of stuck inside because the gases act like a greenhouse what they mean by that is if you've ever been to a place where it's fairly cold and you can't uh grow plants all year round in that kind of climate then people will use kind of like a plastic or a glass building where light can come in but it'll keep the kind of inter inner temperature kind of at a nice stable kind of relatively warm temperature and humidity and so the same thing is what happens here is that the greenhouse gases can function like this greenhouse and maintain some of that temperature so when you have the atmospheric carbon dioxide and the other greenhouse gases that traps and heats and warms the air and it is what we know now as the natural greenhouse effect so that's one of the reasons why our planet has been so amazing is that we have this natural greenhouse effect however what is happening within recent years meaning decades or even 100 to nearly 200 years now is that there has been a substantial increase in greenhouse gases and when that happens that means more heat is trapped it's kind of like if you think about kind of like when during the cooler season you might put on a thick comforter and then during the warmer season you put on a thinner one it's not the comforter itself that's providing the heat that's your body right assuming that your comforter is not electrical um it's your own body but what it's doing is it's trapping it and so if you are in a cold time of year you would want a thicker blanket so that way either more of the heat is trapped and if it's a hot time of year you want a thinner one well in this case what we have is a thicker blanket that is starting to form as it were and that has led to what we referred to kind of in a funny sense of as global warming it's now better known as climate change originally the concept of this was known as climate change and then people started to focus and for kind of nefarious reasons people looked at it and used it as the term global warming and then that was kind of an excuse to be able to say but ha ha look at some of these places they're not warming how could global warming be happening so again the better term for this really is climate change it should have just really stayed that way okay so how do we know how hot the temperature was at one point how do we know what the climate was i mean for the past 20 30 you know some odd years we've had satellites which can give us data for the past 200 years or so we have been able to look at records that people have taken using instruments available to them at the time thermometers and so forth but what about much further back hundreds to hundreds of thousands of years well that's what we'll talk about for just a moment those are called proxy sources sources that you can figure out the information without actually having the direct measure and so one of these very important proxy sources comes in the form of ice cores so people go down to locations where there are very deep ice cores like the antarctic or greenland and what they end up doing is taking a very long drill and then pouring out a long piece of ice and then they look to see what's happening within these fragments of ice so they can kind of break them up into time frames and you can take a look at what's happening with them what's really interesting is if you think about it down deeper in the eyes would be those ice cores that are older and then the newer ice has been deposited on top so you can kind of get an idea of what's going on you can take a look at what's happening with events maybe there was a volcanic eruption at one point in time and that can kind of give you an indication okay we know this volcano erupted in this here and we can see a volcanic layer and that um of ash and that will tell us what year it is in the ice specifically so we can also figure out what's happening by looking at the gases within the ice so you know when you go into your freezer and you make a tray of ice that when you put them in a lot of times once you take them out once the ice has been formed that you'll get teeny teeny little bubbles inside of the ice right well those bubbles contain the air that was found in your kitchen when you started to form the ice cubes so when you put it together and then put it in the freezer and so you could hypothetically take a a sampling tube and remove some of that or melt the ice and then determine within a specialized container how much of it was carbon dioxide how much of it was other percentages of other um gases and so the same thing can happen here that if there is a given amount of co2 that they can identify what's happening with the climate at that point in time because remember thicker layer of carbon dioxide and other atmospheric greenhouse gases the warmer it was so again you can also take other information that might be found within those ice layers for example if certain kinds of pollen had blown over into the areas where ice was being deposited then you can kind of get an idea well these pollen grains belong to this kind of plant and this kind of plant requires this kind of environment so therefore it must have been at that particular climate or no volcanic ash layer can be also very handy in many ways because when the volcano erupts it spews out a number of items sulfuric acid and so forth and carbon dioxide but when the volcanic ash layers are in the air and then up into the atmosphere they cover up the sky fairly significantly so that enough of the sunlight or not very much sunlight gets through and so you end up getting a significant cooling at that period of time so if you look at it you see a volcanic ash layer within your ice core you say okay that correlates with the carbon dioxide showing there's not as much carbon dioxide and we can see well therefore it must have been of different temperature than this place that did not have a volcanic ash layer at that point in the time in the ice core all right so other things that are really interested in terms of being able to identify past temperatures um are to look at sediments or layers so what geologists will do is look at the textures of each sedimentary layer and it'll tell them what the environment was like when it was present that what the like was the environment was at that present location when that layer was formed so they can use the textures to identify what are called faces if the environment changes a new sediment layer is formed and you'll get a new texture so for example if they see in a particular sediment layer that there's limestone well they know that limestone forms in deep marine environment from precipitation of calcium carbonate calcium carbonate comes from little organisms that have shells and when they die they land in the um in the sedimentary layers these are typically going to be limestones are going to be formed in deep water if the layer above it for example were shale is made of fine clay particles and therefore would indicate deposition in relatively still water and then say for example if there were sandstone on top of that well that's made of slightly larger grains and therefore for them to be deposited the science the sand has to be deposited in water that is moving slowly so what that's telling you is that would be in shallow water the water that's moving slowly so this story of having limestone and then shale limestone being the oldest deposited first and then shale and then sandstoe being the the most recently deposited sedimentary layer it would tell you well the water is getting more shallow over time and we know that that indicates when there's more shallow water that means more water was locked up in polar ice and that would describe a colder climate that period of time so you can see a lot from these sedimentary faces you can get quite a significant amount of data from them from about a hundred thousand years old to about eight hundred thousand years ago so that's what uh y a stands for years ago similarly we can look at the middens of pack rats and this is kind of a fun thing to look at because in pack rats they are like their uh name implies they like to take little materials and put them inside of their uh fairly complex living spaces so they create these holes that have many quarters very different rooms in them so for example they'll have the place where there's the nursery where you take a care of the baby pack rats and then another room quote unquote would be where the pack rats sleep or another one would be the bathroom and the bathroom is a location where these pack rats will take their uh little belongings that they have found outside um for example leaves or sticks or pieces of bone or whatever they find interesting and they will put them into the bathroom and it sounds funny but they urinate on them and then that's kind of like a possessive thing but at the same time over time you have many many generations of these pack rats living in these holes in these tunnels and then what ends up happening is you get these layers upon layers of what these pack rats have been taking in and so from there after um over a period of time the urinary urine evaporates and so you just have a crystallized version of what's of going on and so you can see very clearly what the different layers are telling you so middens refers to the trash so for example the little pieces of and heaps of whatever they're collecting you can tell what the environment was like based on the kinds of sticks or leaves or anything that they've brought in kind of ironically when you look at fairly current packratmans you see a lot of trash from humans any case this information can be quite old you can get pack rat mittens that have been found in tubes that have been used for millions of years 2.5 million to about 12 000 years ago all right another way of looking at sedimentation is looking at what's happening on the seafloor and this is very similar in terms of method to getting ice cores instead what we're getting is a core from the bottom of the ocean the sea floor there's a long kind of drill that's pushed down into the sea floor and then as it comes up and it releases it loses its water it becomes compacted and you can kind of look at the different colorations of that it tells you a little bit about what's the composition of the sea floor and from there what you can do is look at the layers that have been formed and for example you can see whatever little um calcium carbonate based um organisms have died in there what the sea was like around at that time so with this information um about two centimeters which is a little bit less than an inch that tells you about a thousand years worth of data so this right here just this little space right here is about 20 000 years worth of data so they can get information about the climate 20 000 years ago from this pretty amazing so another way they can do identify what was happening with global temperatures is by looking at coral coral as you know is an animal and they are like anemones except for anemities are very squishy coral have these little polyps on the top of them and those polyps are what they feed with but generations upon generations grow upon this coral skeleton and so what ends up happening is um if you look at the the skeleton and you take a core sampling of that um kind of like we were talking about with ice cores or um or sea floors then you can look at what's happened over time and of course the ones that are deepest are the oldest parts of the coral and the ones that are up near the surface are the newest now what happens is corals can grow in rings kind of like trees can and so what you can do is then identify by looking at the rings um what was happening that particular year for the coral so in a particularly good year then they would grow a lot in a not so good year they would not grow very much if at all and so what makes a good environment for corals is really largely based on something very interesting corals have a mutualistic symbiotic relationship um with many different kinds of algae or cyanobacteria and these organisms will live within the little tentacles of the corals and what happens is the corals will give them a home and protection and the cyanobacteria will actually produce a little bit of glucose so it's a way of getting extra nutrients well however if you're getting some glucose that means you're doing some kind of photosynthesis and that means you need sunlight so if a coral is at a certain depth then that might be perfect for the sunlight to hit it go too deep and now that coral can't get enough sunlight go to shallow and that means that you're in danger of having these corals bleached or dying from the sun so there's this kind of goldilocks level of not too deep not too shallow but just right so when that happens they get a very good amount of photosynthesis and they survive very well however when it's too shallow or too deep not so much so we know what can change the depth there is whether or not if the temperature is say very high then the ice from the polar caps will melt and that means the water will be up higher and deeper however if it is very cold the ice will be taken into those polar caps and then the water will be at a lower level becoming too shallow for these coral rings so this kind of information can tell us about hundreds say three four five six hundred years ago in terms of what was happening in terms of climate now similarly to the coal rings you probably already heard about tree rings and that trees form these different rings on it basically an annual basis this uh form of science is called dendrochronology dendro referring to tree or branching and chronology referring to time what you do is you take a little core kind of like the core example that you would use for um coral or cinnamons or ice but it's much smaller and you drill that within to the plant and then you can remove the sample to see what the rings look like now just to give you some ideas here this is a pretty awesome kind of tree it's called a bristle cone pine we're lucky enough here in california to have bristlecone pines so if you ever have the chance to see them you should you can see them on the same track as going to see the giant sequoias for example the bristlecone pines are located if you take the eastern side freeway the 395 going north so this is pretty close to um kind of near on the nevada side of the sierra nevada mountains so if you go on the 395 freeway up to say mammoth or bishop in that area at some point if you go up high enough you get to the bristlecone pine forest which is located on the white mountains to the east of the sierra nevada kind of in between nevada and the sierra nevada mountains so what's happening is if you come from the west and then you hit the sierra nevada at this point in time rain showers on the western side of sierra nevada but less of it hits on the eastern side and even further going east you even get less and less so these bristle cone pines get very very little water and so they have a unique way of surviving you can see that this tree doesn't look that amazing in terms of having a lot of growth on it you know what that's a survival technique it survives by shedding a number of its leaves so only the ones that are remaining photosynthesize and as you know lose water so by doing this these trees are the oldest living things on the planet the oldest living one is about 5700 years old so you can get some pretty amazing data looking at that if you're careful same thing with the giant sequoias you can take a look at those if you go to the giant sequoias in the sierra nevadas you can see that they go very wide and giant sequoia is known as sequoia dendron gigantium you can see that it's a really big tree this one even isn't even one of the bigger ones let me tell you you can see this little man down here by it but you can do the same thing where you get a core from that and these trees live hundreds to thousands of years so you can get a lot of information from them now you don't have to go to these trees in particular but you can go to other forms as well so just kind of going into different kinds of regions you can get different information so how does this work as we said before you can take a core from a living tree you could also because of the way would preserve so well you could take a core from a tree that has died but still has the apparent rings in them or you can take them the pieces of wood that are found from old archaeological sites that may have used wood so in any case what you do is you you look at the tree's core and if you're going all the way through the outermost edge is going to be what is formed this past year as you go inner towards the inner part of the core that means you're getting older and older and older meaning when the bait when the tree was younger so here at where this dark area that's when this was a sapling a baby tree so what you'll notice that there are these rings and each ring is basically made up of two portions kind of one of them that's dark and one of them that's light so for example you can see there's a very big light portion right here that is called spring wood or early wood and that's because it grows during the best part of the growing seas of the the growing season during the year and that would be during the spring typically then as summer comes up or an autumn so by the time you get to that then you have your late wood so that's going to be summer or even into later into autumn and that right there you're going to get fairly little growth and then during the winter there's basically depending on the season and the particular location and the kind of plant you're not going to get much wood ring at all much growthing both rings at all so what you end up getting is from a large a large uh light colored area and then a darker area you get one years of information and that will tell you okay was it a good spring well if you think about what's a good spring for a tree well lots of water adequate sunlight those sound like pretty good things and then what would be bad for a tree to grow so when is it going to stop growing usually not enough water or a very dry season very hot season not enough light that kind of a thing so when you go back in time you can say okay good year and then over here not as good of a year and then this one with a little dot on it not a good year at all so what you can do is then you can count back and these are annuals so you know how many we're talking about this one is say from 1930 1920 oh here was that year that was really hard drought for example this area did not get much water so we got very little growth right there for example and then you take a look at it and you go okay then here is a little maybe they'll have a scar in there when there was a fire and people will say yes i remember in uh 1902 or whatever there was a big fire in this area so those are just examples and then what you can do is lay one core um to the side of another core and then you can correlate to see what their rings are doing and you can say okay now we're matched up here's 1900 here's 1910 and then we can go further and further back and you can continue doing this as you can see with all of these um core samples that are here for many thousands of years like i said even with a bristle cone pine after like 5 000 years old so and if there's residue from older ones you can imagine it's even further back than that so you can get a lot of information that way all right trees can tell us other things or plants in general in terms of what was happening with past climate in terms of temperature more specifically one of the things that you can look at is the density of stomata found in the leaves of different plants so for example on this ficus plant you see some stomata here the stomata are the teeny little holes in between those two darker colored guard cells and if you recall the guard cells are what open and close to allow for the stomata to release or to allow in certain gases now you can find these stomata very easily when you look under the microscope like we did in our lab too and also you can find them in fossils so you can take a look and you can see the little stomata here throughout and that'll tell you a lot of information so we know again that carbon dioxide comes in into the plants through their leaves in through the stomata and then we know oxygen goes out and then of course water will go out too so this will tell you a lot about what's happening now what people have done is they have started sorry let me switch that people have started looking at what's happening under experimental conditions for example if they take some plants and they place them under experimental conditions where they've put them the plant in the chamber and then put an extra amount of carbon dioxide in there okay well we know plants need carbon dioxide right they're what i hope you remember they need them for photosynthesis so when they need the carbon dioxide for photosynthesis if there's a lot of it well the plants don't really need to make these a lot of stomata they need stomata for sure they don't just need to make so many and why that's important is because it's kind of expensive to make stomata with their guard cells they're specialized cells so in this situation where there's they're grown in high atmospheric carbon dioxide you'll end up getting low stomatal density in contrast if you grow them under low atmospheric carbon dioxide then what will happen is they'll grow a lot of stomata to be able to get enough um carbon dioxide to do the amount of photosynthesis that they need to do so similarly what we can say is the reverse would be true if you found a specimen either a fossil or a live plant and you saw a low stomatal density well that would tell you hey that indicates high atmospheric carbon dioxide and we know high atmospheric carbon dioxide is like a thicker blanket right so that means the global temperature would have been higher also if you look at the high stomatal density there's a lot of them that means they needed to get more co2 because there wasn't much available they made more openings and we know low atmospheric co2 tells us vendor blanket and so therefore we're going to have a lower global temperature lots of cool stuff that you can learn that way now that's not all i'm just giving you a few examples for example you can look at pollen and you can see what's going on with pollen if you find it in layers lots of cool stuff so from all of this information and more what we can do is kind of create a history of what's going on a history that it predates humans being able to actually measure it and so what we see is that at given periods of time that we see the surface temperature goes up and then it goes down and then it goes up and then it goes down then it goes up so in pla past climate history we can see that there are natural fluctuations periods of time where it's warmer and periods of time where it's colder now this is one piece of information that has given climate change deniers some misplaced information the fact is is that the people don't understand that the timeline is what matters here when we take a look at it between one period of time and another period of time when it was low versus high we're talking about you know uh 500 000 years or it can be 50 000 years but quite a long period of time 100 000 years between these shifts okay so yes there are fluctuations but take a look at that time scale we'll talk more about that in a moment so when we can get more information that's more recent we take a look here's about 20 000 years ago we can see that the data indicate to us that at one point about 10 000 years ago there was a fairly substantial change in temperature globally and that has been largely attributed to when agriculture was established and there's a correlation there but it kind of makes sense too so is the correlation really a cause and effect so it is likely that there's the cause and effect because if people are doing agriculture many times what they will do is cut down the local plants there burn the soil and burn the plants and that will release the carbon the nitrogen in those plants so that the soil becomes very arable that people can grow on and so at the same time as releasing carbon dioxide through burning they're also removing a lot of plants which take up carbon dioxide so it makes a lot of sense that there would be an increase in temperature as agriculture was established now just so you know when we are looking at current temperatures and comparing them um to some baseline to say is it getting hotter or colder this is the time frame that we can start with calling zero about 10 000 years ago so notice it's even warmer than what we would usually consider as kind of the norm for this planet okay so um take a moment look here we're to go for their agricultural being established here um until a little bit later this is going to be about 2 000 years ago so here we're starting about here in um in what's going on okay with our particular graph so here we can see this is showing from about year 0 you know right as we count it and then one ad would be right after that and then here is a little bit you know not quite as as recent as here now today at 2021 but if you notice then we'll see that there are periods of time where it got warmer and cooler now what are all these colorful lines some of them will be indicated from say still model data some of them will be from ice core data some of them will be from the sediment data so all the different kinds of examples i was showing you okay so here we've got all the data but what you can see there are some uh warmer times and this was called the medieval warm period it happened to be a little bit warmer during that period of time and then there was also one point that was called the little ice age uh kind of in uh the 14 15 16 17 around that time hundreds and then we can see what's happening now more recently now what's interesting is we're going to take a moment and we're going to zoom in from about a thousand years ago to currently and we're going to see so that was the medieval warm period to currently and that's what is represented here by the purple okay so you can see there are still some fluctuations that's going on which makes a lot of sense okay and then you can see at one point in time they're going up and down and then starting around i don't know it maybe looks like 1850 or so you can see an increase there right so what's happening starting in 1850 so for those of you who remember your history class that was a very important time for humanity right that was the industrial revolution and during the industrial revolution what we started to do was produce more carbon dioxide by making factories by making machines run on gasoline and so forth using fossil fuels in general okay so now taking that area we're looking at again um here we're looking at about 1850 or so and we're going to zoom in on that a little bit here's 1860 to relatively current and you can see the trend although it goes up and down is really increasing over time so what we have to notice is that the time frame here when did we start seeing this happen we're really looking at about 150 years ago this is very very very different than the natural fluctuations that would happen over say 50 000 years even over 10 000 years this is a very very short period of time geologically speaking we're talking 150 years only a couple of generations of people that's what makes us very different so one thing we're going to talk about is looking at your carbon cycle activity and that is going to be in your study guide so i'm going to go ahead and get that and then we'll take a look at it together so okay we're almost there almost there okay so all right so here we are at the section 5 study guide and we can see those are the learning objectives that you've seen before and we're going to have talked about this by the time that you see this video likely this is the one that i was looking at first okay so it's called climate change so let's take a moment and look at this based on what we have previously learned what are the two metabolic pathways that fit in the boxes a and b below so can you figure it out which one is a right here you can see that it's giving off carbon dioxide so what would that be hopefully you'll remember that it would be cellular respiration that will give off carbon dioxide right and b we're taking up carbon dioxide so we can see that would be what photosynthesis okay so a is cellular respiration b is photosynthesis all right and it says number two analyze the diagram of the carbon cycle which of the lettered items increases greenhouse gases so which one is it cellular respiration or photosynthesis all right good you can see which one's giving off is going to be cellular respiration now i'm going to go ahead and and slide down a little bit lower on this picture on our screen here so i'm gonna have to clear off some of this stuff here okay so what you need to do is number three describe why you wrote the letters you did for the question above why is that pause your screen your video and go ahead and see why that is all right now come back and say now what would happen in terms of carbon dioxide if the amounts of plants in the picture decreased what would happen go ahead and pause and write down what you think the answer is okay now number five what would you predict would happen to the temperature if say number four happened go ahead and pause and write your answer okay good now there is one last thing that i need to point out to you before we uh move back there is a particular activity that you need to do on your own called understanding climate change and ozone depletion there is a certain amount of overlap between these two but there's a little bit of confusion too and it's easy to see why people would be confused so i want you to go to the website here and to your textbook and see if you can figure this out and then also this won't have an answer key in the study guide answer key so this is one thing you want to prepare before your exam okay so now that we're done with this i'm going to go ahead and switch back to our lecture okay let's see i'm going to move back to where we were at okay so what we learned about this in the carbon cycle that i was showing you is that it turns out that cellular respiration as we know one of the products is carbon dioxide and we can look here that in photosynthesis will take up carbon dioxide so there's very much this cycle that's been happening a long time and of course if something dies and doesn't get eaten then it decomposes and then you lose cellular sorry you lose carbon dioxide also so that's all the same what's been new however as i've mentioned before is the burning of fossil fuels and wood especially within the last several hundred years and this is increasing this is something new that hadn't happened before that time not in any great numbers so what we can see here is we've already noticed that there is a distinct relationship you can see it here a correlation between when carbon dioxide goes up the temperature goes up when carbon dioxide goes down the temperature goes down and there's this really nice connection so you can see if carbon dioxide is continuing to go up as we've seen then we can expect something to happen to the temperature what should happen what kind of relationship is this is it a direct or an inverse relationship now to let you know these units on the side are in parts per million and this is an interesting concept because uh researchers have found that to be able to maintain the same climate as we do now we need to have about 360 parts per million the question is have we already gone up are we above that are we about to go there will we go there and if so when so those are some interesting questions and then we would see what will happen with our temperature okay so if we're looking at this we should also probably give a little bit of attention to another greenhouse gas here's an interesting one methane so a number of years ago i had a student who asked a question and i thought it was a very good one his question was well i know that carbon dioxide is an important greenhouse gas it affects us a lot but i remember you saying methane and from his own personal experience he knew that rice patties the way they are currently growing um produces a lot of methane too because at near harvest people have a tendency to flood the fields and that means that the plants aren't getting any oxygen they start to decay and the bacteria produce methane so there's a certain amount of methane that's that's produced so i said yeah well that's a great question let's take a look at that and see what's going on and so i got some data um took a lot took a a number of uh we got the data from a particular source and when you take a look at it you can see this is over you know a 10-year period or so not quite a little bit over 10 years i guess right and um but you can pretty much say when you look at the numbers that um you know these all kind of stay within their same levels so for example these are in um equivalence of co2 but they are a given amount of methane so first of all the highest sources of methane are landfills so that makes a lot of sense so um i'm wondering have you ever driven the 52 freeway going to say la jolla going west from santee when you do sometimes you end up going over these dips right they get to be quite uh high and low i know that i used to take my kids on them periodically because i thought it was fun like a little roller coaster right and sometimes you'd see the signs and there wasn't much of a dip and then other times you'd see the same signs and it was really like a roller coaster have you noticed that well to the north of that so facing to the right from when you're driving west then what you'll see is the miramar landfill and that landfill has got the trash that san diego gets rid of and so they bury that and then what happens is it starts to decompose now unfortunately it's continuing decomposing but without a lot of air it's going to go into anaerobic respiration and then we end up getting a lot of methane from the bacteria that are produced that are breaking it down so methane is coming up from a lot of our landfills which is why it's important to turn them over so frequently now other kinds of systems that we get it from are natural gas systems you can see coal mining here wastewater treatment you can see all kinds of examples here i've highlighted in color these two right here because my student asked me he said i know about rice cultivation and i heard that cows have a tendency to produce a lot of methane too so that's why i have this picture of this cow uh defecating as it were pooping and so one of the things that happens is when cows defecate when they produce poop they have bacteria in there they've been the bacteria have been helping them with breaking down the plants that they're eating and so when they leave a cow patty then if it were say out on a range where there were lots and lots of cattle spread out over a big location then the little poops the patties would dry up and the bacteria would die fairly quickly however that's not how most cattle are grown nowadays um instead they're produced in what are called kafos let me write this down so kfo stands for concentrated animal feeding organization so a cafo is basically when the cows are at a certain age and they are really getting ready to be slaughtered within the last couple of months in their lives what people want to happen is for them to get heavier really fast because they are sold by weight and so they can get more money for a heavier cow okay so what happens is instead of allowing them to move around they put them in these concentrated animal feeding organizations these cafos which are relatively a small amount of size so they don't walk around as much and on top of that the cattle have a tendency to walk and then they poop and then they walk and then they poop and it becomes this huge amount a big bound of fecal matter right of waste and um the cows just walk over it like it's a hill like any other hill but what happens is during that period of time they have a tendency to get bacterial infections because they're walking in wet poop a lot and so to stop them from having infections before they get slaughtered they give them antibiotics so that they don't you know get sick from the bacteria well fortunately if you're a cattle person the other thing that comes along with antibiotics is weight gain and so sometimes people will go ahead and give them the antibiotics even if they don't need it so now you have to think about it if they're now being medicated and that goes into their body is that what you're eating so that's one question too but here going back to the main story about methane what you're looking at here is the fact that unlike where they can produce individual little cow patties that can dry out when they form these huge mountains of poop it doesn't dry out and just like within the landfills they have a tendency to have bacteria that continue to decompose it they stay alive and they produce more methane so looking at this you've got two things kind of in this yellowish color enteric fermentation so you know about fermentation that's what's happening when you're breaking down glucose right in this case enteric means within the gut so when fermentation is happening you know gases are released but in this case it's going to be gases from the bacteria in the form of methane and the cows really blowed up from it and there's not really much they can do except for burp it out it turns out it's mostly burping sometimes farting flatulence as it were um that results in the methane coming out otherwise the poor little guys would be just bloated and explode at some point right that would be horrible in any case so from really mostly burping you get a lot of methane that's really released the other issue of course as i've kind of alluded to is manure management and that's because as the cattle are walking around it's not drying out so if they're not managing it by removing the the wet manure and they're not spreading it out and getting it thin then it's going to continue producing all of this methane and so really when you think about cattle production you really need to think of both of these numbers together which is quite significant it's getting close to landfills but maybe not quite as high it's probably like second uh compared to landfills and in some cases even higher you can see here on these numbers so just depends on you know a particular year now about my student's question he asked about rice right well yes it does produce methane but when you look at it the quantities of methane are nowhere near what you get from producing cattle so we know that you know both contribute but um the livestock industry is a really really big one okay so that's about methane now one of the questions that people will ask and should be knowledgeable is about well what are the consequences of climate change and perhaps you're familiar with some of them or maybe even all of them but it's kind of amazing to see them in action so for example glacial melting we know that this is an issue here is a picture of a glacier taken in austria in 1875 and here is the same glacier that is non-existent as of 2004. it's gone there's just water from where it was before there are also consequences as uh well about the polar ice melts which you've probably heard about before looking at these arctic boundaries these are pictures that are taken during the same time of year so these would be both during the um the warm time of the year and you can see how much it's receded there's not as much left now also because of all that ice that's potentially melting where does it go but into the ocean ultimately right so as the ice is melting the water is getting higher another thing i should mention is notice when you're taking a look at these ice caps right you see that they're white so they're going to be reflecting a lot of the sunlight that's called an albedo quality i'm going to write this over here albedo is a reflective quality about light and so ice has that being that it's white but as it melts the ocean is no longer with an albedo quality it's dark and it actually takes up quite a lot of heat and so that reflectance is not helping to stop this from continuing to go faster and faster so what happens is that means that as the ice is melting as the sea gets higher there's more and more dark ocean for the sunlight to be captured in and so it ends up being warmer it's very much quicker this way now people are aware of this that there are challenges um and so there are many places um that are trying to deal with this in figuring out what's going to happen if i live on a shoreline for example you can understand the people in louisiana florida is very much a hot spot for studying this and so they've made projections about what if it gets to be say six meters of inundation six meters of sea level rise that's kind of on the high end but not unheard of or not impossible and um i have been talking to some friends who actually work in the military bases in virginia and they were telling me about some of their experiences so for example in virginia you know there's a lot of military bases um particularly in the navy and um they're there because they're coastal right and so what they've noticed however with sea shore or sea level rise i should say that the water will inundate as the tide goes in and it gets to new areas that it hadn't gone before so an area where people have built say a church or say a naval base what now what happens is where the people are parking their navy their cars when they go to work for the naval base that parking structure can get flooded so it's become quite regular for my friends when they're out on you know on the ship even if they're not far away that they have somebody back in the base that actually goes to relocate people's cars off the base for a given period of time so that they're not flooded during that time so the navy is thinking what are we to do are we going to move the base ultimately are we going to put barriers up in place these are active discussions that are occurring within certain groups in the military and it's affecting people now so here's an interesting example um that i want to describe to you so as i was saying that there have been projections in terms of um how high this this water can become and one of the things that they're looking at is um that recent satellite um observations have been noticing thinning in parts of greenland um at the lower uh elevations so a partial melting of this ice would cause one mil meter or three foot rise but if it were to melt completely the greenhouse sorry greenland ice sheet contains enough water to raise the sea level by five to seven meters so that's the amount that i was talking about just a moment ago and so people are trying to be forward thinking and see what to do one of the countries that has dealt with water issues throughout its entire existence is the netherlands netherlands means neither land neither land means the nether regions meaning lower that means they're actually lower than much of of the ocean level so sea level you can see that there's actually i'm going to scoot back here about 26 of the dutch population is actually living below sea level so they've had to deal with this for a long time and in making projections you can see here in this red area that's looking at amsterdam which is uh the major city there it's circled in red here as well and um what has happened is that in order to be able to maintain this land the dutch have been manipulating the ocean for a long time they built what are called dikes and people realize that without the dykes that they've been put in place the country would 26 percent of the country would already be below sea level so you can see kind of the differences in shapes here this little line coming here this little set of islands right here this is amsterdam it's completely underwater if they hadn't been building these dikes so there's a saying god created the earth but the dutch created the netherlands you can see why they've had to actually reclaim land and so they've been fighting this issue for a long time it's part of their just kind of their history there so another example of this here is looking at this small area you can see the red lines and the yellow lines those are the dikes that they've put up to basically save the land so people can stay living on it right so this is the current land system you can see i'm sorry current dyke system with the yellow the blue and the red all of those are dykes and this is quite an endeavor that they have to deal with um they go through dike inspection and repair on an annual and sometimes bi-annual so two times a year um basis they're doing this digging out basically the sand from the ocean and making these dikes back up they go out to to the ocean here and use huge ships that basically spray back sand into these areas so that they can maintain where they live so the dutch have been involved with this for a long time they've been dealing with the concept of climate change because remember this would be um if they didn't just have dikes now what would happen is all of this space in red right here would be underwater so it's more than just little amsterdam that we're talking about a huge percentage of the country would be gone and so they have to think about this all the time in fact my great uncle who just recently passed away was working on these kinds of concepts to maintain um the the land for the netherlands now as an example of some of the ingenuity um in the netherlands they've come up with um an interesting idea in the city of rotterdam rotterdam has uh this area which is called um bente blan and that particular place has a square that you know where people will gather and have coffee and eat lunch or whatever and in this little area they built it so that all the um particular items that are um that are here can flood and so when it gets to be a very rainy season if there happens to be extra flooding they can channel that water to this area and nothing will be affected by it the people won't be harmed they just don't go into that area so i mean if you can't get rid of the water where are you gonna put it you just put it locally and let it sit until it evaporates or it goes out through other channels now here's another amazing um construction kind of technological issue or management system that they've come up with it's called maislam caring based on caring is a really interesting thing where basically they have these two huge gates okay these are huge like doors that close off and when it becomes three meters higher above the current sea level these will close up but they can take up until five meters of the current sea level and here you can see just to understand the scale of this this is the baseline caring right there those are the two kind of structures that are the doors that block off this part of the netherlands fascinating to think about how much effort that this country has been put into it but you got to think about it also think about how much money they're putting into it an effort right not everywhere in the world are people going to have these means the the netherlands is a fairly rich country um you know it's a small country but it's fairly rich and so i mean it kind of has to do these things to be able to survive and continue the way it's prospering now but what about those countries that are not like that so um here's like an example of the amazon delta where we can see large areas of water that would flood this region the area in red here which is the amazon amazon delta region has four million people that live wherever this red is they would be flooded completely in another favorite spot of mine this is indonesia where my family's from you can see this is uh jakarta which is where my family was born on and in jakarta um in this island of um we've got some of the major islands like sumatra and so forth in jakarta there are 10.56 million people that are living in this region that could potentially be affected that is not including all these areas in red we're just talking in the areas of jakarta so you know how are they going to deal with it they can do technology too but very expensive right here's an example of an amazing little country called the maldives islands let's see if this is still sharing here okay so the maldives oops sorry i don't know why that happened let me switch over here get to the right spot sorry about that okay so this is the maldives islands where um there you know are over three hundred thousand people that live on two hundred of its eleven hundred and some odd islands okay now these people are living at an elevation of 1.5 meters that is incredibly low right what are they going to do their highest region is a little bit taller than a person right so what are they going to do or actually even a little shorter because i'm already 1.74 meters so this is a shorter person that's the tallest part of their islands where do they go so there's a lot of interesting questions and um there have been a lot of pleads on behalf of the maldives islands by their leaders to do something about climate change because they don't really contribute to it themselves but they're feeling the effects and will feel the effects at a much stronger degree than you or i will they'll lose their country now there's an interesting kind of caveat that goes with this because the maldives islands has a people and a culture that has a rich history and one of the parts of their history is that at one point in time the maldives islands according to their history sank in the ocean now of course what we know is that the sea level rose instead of it's sinking and according to lore um god raised the islands above them above the ocean level and save them so it's probably some form of climate change right but the way people look at it is that they were saved and so for many people who are very much entrenched in their beloved culture they also are not worried because they feel that god will save them now that might be the perspective that people have but if you're taking care of this country you can't look at it and say you know i can't do anything when we're already seeing sea level rising what we can see is that sea level has been rising over time and um you know it's if we're talking about it already being you know five millimeter or five centimeters and 10 centimeters and 20 centimeters then people start to get very concerned so one of the things that has happened it for these people is that australia has been been taking a very proactive look at it and saying well what we should do is have some people migrate to the united states if they're willing to and they make a pretty sweet deep to the united states to australia and they make a pretty sweet deal and the sweet deal is for young people who are interested in going in the medical field for example for nursing in particular because that's what they really need they can come over to australia and they'd be educated there and so forth and then if they wish to stay they can or if they wish to go back home they can but at that point they would be bringing their education back with them and saying well maybe we should also look at what we can do because we don't know what this is going to entail in terms of talking to the elders who are very much um very strongly believing about them being saved so you know is that okay i don't know um you know in terms of you know influencing cultures it's a pretty challenging thing right but at the same time at least there is a look towards possibly helping people who really need help and that's not the case everywhere um many times people are very reticent to take in migrants as you all well know um because not every time that you get um immigration are people happy with that right and so you know there often are cultural conflicts financial conflicts all kinds of ideological conflicts and um so you know that's one thing and another thing that's really interesting is um we know that there are rules in terms of how many people can come into countries by their migration rules but there are no allowances for people who are refugees due to environmental catastrophe there are rules for people who've been persecuted for religious reasons um for other you know personal reasons like their personal safety their word of murder or something like that being murdered by somebody there's a lot of reasons why you can but looking at an environmental catastrophe like climate change there are no rules for that so what do you do about environmental refugees it's gonna happen so now let's take a look a little bit more of a look at this i know that i've told you that we call it climate change and global warming i also like to little bit call it global weirding because one of the things that's funny about it is that we think about global warming right so it should be getting warmer but then what happens if you start to see things where there's a lot more rain let down well it doesn't make sense at first but when you think about it as the global temperature increases there's more evaporation that makes for more water in the atmosphere which then can come down in storms and so you end up seeing lots of kind of crazy things like super storm sandy i don't know if you recal recall this but um several years ago there was the major um storm that really was a combination of several storms that have come together that originally and ultimately struck from the caribbean all the way up to canada and one of the major areas that really started to recognize this was new york and that's because that metropolitan area had not uh really felt the effects like this before so to give you an idea here's an example of an amusement park that was hit and i just thought this was an amazing picture because you know what this is a roller coaster underwater do you see that it was just amazing amounts of um movement of water and storm and so forth here's what happened with the flooding that came from superstorm sandy the new york city subway was under water i can't even imagine and people who were living there they saw their actual streets that were um flooded by superstorm sandy this is the first time that any mayor had actually taken recognition in new york city and recognize that climate change was an actual thing so it took unfortunately some personal experience from that right now of course in addition to that more global weirding we could see increased flooding that happens and a lot of countries that are really um in danger of this would include countries like bangladesh and if you can see here a lot of them in southeast asia right um we've seen other areas like the netherlands we'll see other areas like along our coasts but the thing that i think about when i see it in these particular areas is that the people are already dealing with a lot of issues in terms of poverty and then to keep rebuilding after this and not be able to be preventative about it is another issue and a lot of times many of these countries especially the poorer ones are not actually contributing to the carbon dioxide to the same levels as other countries are for example the united states so another thing that you may or may not have heard of is ocean acidification so uh we kind of alluded to something related to this when we were talking about measuring um how much carbon dioxide was given to fish not so much ocean acidification but the process in which carbon dioxide becomes incorporated in the water when the oceans are of the sea waves are are fluctuating then a lot of more carbon dioxide ends up becoming incorporated in water and of course you combine carbon dioxide and water and now you get carbonic acid remember we said an acid is something that donates a hydrogen or many hydrogen ions and so that makes it a lot more acidic right and so because of this you end up seeing coral reefs that end up dying from ocean acidification their skeletons are made of calcium carbonate and that starts to dissolve in acid same thing looking at this here there was an experiment done where they took shells and seawater put it in the projected ph of 2100 and over 45 day period the shell was dissolving what about all these organisms that produce shells like clams or mollusks in general like snails or arthroplot pods like crustaceans including you know crabs and lobsters what happens to them in the corals in the ocean that's a big thing to consider other consequences more global weirding extreme storms or weather events we could talk about things that have been happening like heat waves for example there was a heat wave that happened in it was in 2006 and in 2006 when that happened there were over 739 people in chicago that lost their lives to heat waves which is really crazy to think about because we don't usually think about you turn on the air conditioning right but some places don't have air conditioning or some people can't afford to have that right and so a lot of times what ends up happening is the elderly die and people don't necessarily know what's going on with them because they'll close up their windows to keep the cold air in but in the same time that's what ends up happening that particular heat wave that i was talking about in chicago um killed 739 um people there were a little over 200 in new york in that were killed from superstorm sandy so that gives you the scale of what we're talking about that this can be really big now um there have been um also some instances that you've just heard about recently for example the 2021 snowstorm that just hit in texas this last february it really surprised a lot of people there um with that winter storm they don't usually get that kind of snowfall or intensity and it really um affected them because they got a lot of precipitation very quickly in an area that normally doesn't deal with snow they lost their power and had a lot of accidents and a lot of deaths happen there as well because of this now you're saying again how come it's you know a snowstorm when we're talking about global warming well remember there's more water in the atmosphere because of what's happening in with heating up in general and then all you need is an arctic blast to come down and now it's super cold cools it and there you have a snowstorm and you end up getting it in places that may not be able to handle it or places that do but not to the extremes that you're talking about as usual now let's talk a little bit closer to home because you know it's hard to visualize what's happening in bangladesh in texas unless you've been there right so you know the consequences here in san diego county water shortages this is a chronic problem for us we have droughts all the time and the ironic thing is is that even if we get one or two or three years of good rainfall it doesn't necessarily fill the large um areas underneath the land called aquifers where we get our water from that we're drinking water so sure we might be filling up a little bit just to temporarily ease it but it would it would take probably decades of really good rainfall to be able to actually replenish the aquifers that supply our drinking water and water for other things of course another consequence we all know in san diego right looking at those um wildfires right they're more intense they're more frequent they're in places that are coming closer to home so all of that now you know there's a lot that san diego county has to be thinking about the flooding issue that we were just talking about beach erosion and close coastal flooding is something very much on the forefront of the minds of people who work in the governments of san diego uh county and san diego city proper so here is what they're looking at um with an area this is mission beach so if you're familiar with that um these are all houses right here um that are along it and you can see what they've done is they've kind of color coded it with if you only had say 1.1 to 5.3 um feet um of inundation that would be the purple region so you can see already that is already flooding the streets if we're talking about 5.3 feet and above to 9.5 feet then we're talking in the blue regions so remember when i say 6 meters we're talking 18 feet okay so very different scale that we're looking at going to be interesting to think about what's going to happen to the coastline of california so um now i want to ask this rhetorical question here you know people say well you know we have to watch it going be above one or two degrees celsius and because largely because it's hard for us to understand about average for global temperatures partially because we don't use celsius it's kind of hard to visualize this right so what i'd like to do is give you some examples so in the little ice age that i mentioned some time ago from 1350 to about 1850 it was one to two degrees cooler celsius cooler and here you can see a painting that shows this time frame um and how it was depicted people were not doing their usual things the trains stopped people couldn't make it to their usual do their usual farming or other kinds of activities it was frozen people figured out how to you know do ice skating this is a dutch idea that came out because they had to deal with ice all over the land right so it really disrupted people a lot and you're probably familiar with it from uh surprisingly the um the famous art um piece called the scream now this was by moonsh and what he had was depicting here in according to some people's concept was a very stressful time for people it was during the time frame that krakatoa in indonesia had a volcanic eruption and what happened was all that volcanic ash ended up in the atmosphere and floating ultimately across the entire globe and thereby creating the little ice age and so um it was a period of time where it got much cooler and it was incomprehensible to people at the time what's happening this is crazy the skies turn red from from the ash and and the sunlight hitting it so it was a very stressful time for people now um to give you a much broader kind of concept what's the difference between say 2 degrees celsius and 5 degrees celsius because that's hard to visualize as well well that was during the last ice age which was 2.5 million years ago to about 10 000 years ago and that's when you can see a period of time when the entire northeast united states was covered by 3 000 feet of ice there was no new york i mean granted it wouldn't occur for a long time but if we were covered by that there wouldn't be a new york right so that's a much more extreme example but to kind of give you an idea of what is one or two or three degrees referring to in terms of this all right so there's also this wonderful um website that i found about the climate time machine and it's by nasa and i kind of wanted to show you just a little bit of what i found on it that was so very interesting so i'm going to share this with you so the climate time machine has a couple of things for you to look at and if you're interested in kind of viewing it you can do that i've given you the website on the powerpoint but if you notice here you can look at sea level and what you can do is help you with visualization of what it would be like so here we're looking at the arctic sea and we're going from 1979 and we've got the years that we're going through watching what's happening to the arctic sea ice so now we're at 1995 96 we're creeping forward but notice what is happening to the overall amount of ice it's kind of crazy for the first time ever there are places that people have been able to traverse through the ice with their ships because there have been enough waterways less ice in those here in those locations during the cold season scary thought right there's also a way to look at here sea level so here's where i found these pictures that are related to this we're going from where we are now in terms of uh inundation at zero meters sea level to six uh meters so here you can see what difference it makes a meter at a time i'm going to go ahead and show you that one so even if we're just taking a look at one meter look at how many people will be affected or two meters there goes new orleans right or three militers now we're done with miami so if you've been to those places probably that'll mean something to you in terms of that so it's kind of an interesting little website that you can take a look at all right so going back to our powerpoint here um so how much does one or two degrees celsius mean it makes a lot of difference so other things that are consequences you might ask this question about well how could global climate change lead to increased risk for humans to diseases so a lot of times you and i are just lucky about human disease simply because we don't live in the right climate format however diseases that are caused by viruses bacteria and parasites and affect more than one billion people mainly in the tropics where the most vulnerable affect that many people mainly in the tropics where most vulnerable developing world populations are concentrated now we can see the map of tropical diseases like malaria chagas disease sleeping sickness lesh manioces um schistomyosis and dengue fever is starting to change the tropical diseases transmitted by vectors such as mosquitoes flies ticks or snails are directly affected by the conditions in the ecosystem they inhabit such as changes in humidity water levels temperature rainfall so you can imagine if our environment changes that's going to change the way our environment is how we have increased chances of maybe getting diseases we normally hadn't we haven't worried about malaria in a long time here in the united states so this picture right here would be a very good one for you to go over um because there's a lot of examples of different um of different um potential effects of a warmer climate so we can see them ranging from agricultural issues like what crops where what kind of irrigation pest diseases that kind of a thing sea level rise coastal areas we talked about that with flooding um and beach erosion if the ocean takes the sand back what protects us from normally getting pounded more are things like estuaries wetlands and coral reefs which could be flooded and have been largely disturbed by human activity anyway disruption of fisheries are we going to have less to eat in terms of from that perspective as i've mentioned about aquifers if they happen to be along the coastline salt water can intrude in there and now the fresh water is salty water if sea level rises then looking over here weather extremes we've talked about a number of those water resources maybe the water quality is decreasing for reasons we've talked about like drought and flooding and contamination human health just increased deaths from heat and disease but also what about water and food supplies we've talked about diseases that are tropical that could go into new areas increased respiratory disease asthma is expected to go much higher and increase water pollution from coastal flooding biodiversity we expect a number of organisms to go extinct and remember a healthy ecosystem has high biodiversity this might be due to the extinction might be due to continuing loss of habitats and disruption of aquatic life and then also um the changes in forest composition and locations disappearing of some forests increased fires like we've talked about and loss of habitat and species and then of course within the human population just um some other issues that we lightly touched on was what are we going to do about environmental refugees do you ignore people who've lost everything lost their entire land lost their home lost their families are we like that do we leave people to just suffer and there's going to be migration whether or not we want to fight it at all or not because people are going to do what they can to survive and you would do if it were your family right so i hope that this has been an interesting discussion about climate change and remember the idea of this is to give that a scientific background to the to you and to understand how it is that scientists understand climate change also it is not to pre uh produce despair or fear in you but hopefully make you want to do something about it and remember think about the small things that you can do like the ones that i presented in homework 7 and other things as well if you're interested in becoming locally involved in issues related to climate change we have an interesting it's a local version of a larger group called 360.org and what it's referring to here is those parts per million the one here for san diego is san diego360.org but if you're interested in it they can tell you ways of becoming involved don't despair do something about it all right i hope that you found this interesting have a good day