WEBVTT - [Insert Your Own Catchy Title About Younger Dryas Here] 0:00:01.480 --> 0:00:07.680 Welcome to Stuff you Should Know, a production of iHeartRadio. 0:00:11.160 --> 0:00:13.600 Hey, and welcome to the podcast. I'm Josh, and there's 0:00:13.680 --> 0:00:15.880 Chuck and Jerry's here too, and this is stuff you 0:00:15.920 --> 0:00:19.320 should know and what we've got on our hands today. 0:00:19.480 --> 0:00:24.400 Chuck is a hot potato of a real deal geological mystery. 0:00:25.040 --> 0:00:30.000 Hot potato. That's how Emily's family says potato. 0:00:31.040 --> 0:00:33.839 I think I would only say it when it's preceded 0:00:33.880 --> 0:00:35.760 by hot. I would only say it like like I 0:00:35.760 --> 0:00:38.360 wouldn't say I'm going to have a baked potato, like 0:00:38.440 --> 0:00:39.559 you'd be out of your mind. 0:00:39.360 --> 0:00:41.239 To say it like that. Nor would you say a 0:00:41.240 --> 0:00:43.960 hot potato like what a square? 0:00:44.360 --> 0:00:44.600 Yeah? 0:00:44.600 --> 0:00:45.879 That is pretty square, isn't it. 0:00:45.920 --> 0:00:48.320 Get the stick out of your butt, fella, and loosen up. 0:00:48.320 --> 0:00:51.160 Right, loosen up, get the card again out from around 0:00:51.159 --> 0:00:51.840 your shoulders. 0:00:52.080 --> 0:00:55.400 Yeah, jeez, So that was obscure. 0:00:54.880 --> 0:00:58.240 But still so, like I said, this is a mystery today. 0:00:58.280 --> 0:01:02.440 And just to give a brief brushstroke overview with the 0:01:02.440 --> 0:01:06.200 widest brush, real lot of space in between bristles, just 0:01:06.200 --> 0:01:09.039 barely any paint on it. That kind of overview. 0:01:09.400 --> 0:01:09.959 Oh wow. 0:01:10.160 --> 0:01:12.920 What we're talking about is something called the younger dryis, 0:01:13.440 --> 0:01:17.400 which is a pretty it's a pretty terrible name for this, 0:01:17.520 --> 0:01:19.200 if you want to be catchy, right. 0:01:19.959 --> 0:01:21.959 Yeah, I mean I think a lot of people will 0:01:22.000 --> 0:01:23.720 probably say WTF. 0:01:24.240 --> 0:01:26.960 Right, well, let's just call it the YD. If we're gonna, 0:01:27.000 --> 0:01:28.960 if we're gonna put initials on things, how about that 0:01:29.120 --> 0:01:33.479 or a breath other things? So the YD, the Younger 0:01:33.560 --> 0:01:38.560 Dryas is this this surprising, shocking period in Earth's history, 0:01:38.920 --> 0:01:41.840 fairly recent history, where we came out of the last 0:01:41.880 --> 0:01:45.240 ice Age, everything was going smoothly, and then bam, we 0:01:45.319 --> 0:01:48.560 got hit by another ice age out of nowhere that 0:01:48.640 --> 0:01:51.320 lasts for over a thousand years, and then bam, it 0:01:51.360 --> 0:01:54.320 goes away just as fast as it came along. And 0:01:55.440 --> 0:02:02.480 paleo geologist, paleo climatologist, all the paleos are perplexed as 0:02:02.560 --> 0:02:04.960 to what caused it and then why it stopped so 0:02:05.080 --> 0:02:07.600 suddenly too. That's why I said it is a real 0:02:07.640 --> 0:02:09.079 deal geological mystery. 0:02:09.639 --> 0:02:13.760 Yeah. And a time, as we'll see, where the Earth 0:02:13.800 --> 0:02:19.120 and its inhabitants and animals and nature was all going 0:02:19.200 --> 0:02:22.240 like all right, thank god, we can we can finally 0:02:22.240 --> 0:02:26.000 get down to business and start being an earth, like 0:02:26.200 --> 0:02:31.200 a legit Earth. And then you know, the YDS come 0:02:31.240 --> 0:02:33.160 along and say not so fast. 0:02:33.160 --> 0:02:35.760 Right, and you call it a legit Earth because when 0:02:35.800 --> 0:02:38.640 it finally ended, and actually that period in between the 0:02:38.680 --> 0:02:43.720 last Ice Age and the yd those are like really 0:02:43.800 --> 0:02:46.520 habitable for human beings, Like we love those kind of 0:02:46.520 --> 0:02:49.519 conditions so much so that after the y D ended, 0:02:50.080 --> 0:02:53.280 it became the age of humans. Yeah, like this is 0:02:53.320 --> 0:02:56.080 the this is the age where we began our civilizations, 0:02:56.120 --> 0:02:59.119 we started farming, we began to flourish as a species 0:02:59.200 --> 0:03:02.520 and basically take over the planet. And what's interesting is 0:03:02.960 --> 0:03:05.040 this is the most recent ice age. There had been 0:03:05.120 --> 0:03:09.200 seven in Earth's history and just as and aside, this 0:03:09.320 --> 0:03:12.160 was the Wisconsinian ice Age that we're talking about. The 0:03:12.280 --> 0:03:16.040 last one was two hundred and fifty million years before, right, 0:03:16.200 --> 0:03:20.359 So it's pretty significant that we, just geologically speaking, came 0:03:20.400 --> 0:03:22.240 out of an ice age because there's not that many. 0:03:22.840 --> 0:03:26.119 And then not coincidentally, when the second to last ice 0:03:26.160 --> 0:03:29.400 age ended, that opened the door for the dinosaurs to 0:03:29.400 --> 0:03:32.079 come along and take over the Earth. So things, big 0:03:32.120 --> 0:03:34.960 things happen when an ice age changes. So for it 0:03:35.040 --> 0:03:36.680 to switch back to an ice age all of a 0:03:36.720 --> 0:03:39.920 sudden and then switch back to nice and temperate for 0:03:40.000 --> 0:03:42.800 us humans it is just very weird. It was actually 0:03:42.840 --> 0:03:47.440 I've seen it described as an extreme weather millennial event. 0:03:48.560 --> 0:03:50.480 Yeah, and you know, it kind of made me wonder 0:03:51.480 --> 0:03:54.520 had this not happened, because we were sort of headed 0:03:54.520 --> 0:03:58.800 toward you know, legit Earth, like I said before, you know, 0:04:00.000 --> 0:04:02.000 I mean, it would obviously wouldn't change the year. But 0:04:02.160 --> 0:04:05.000 let's say, as far as longness goes, we would be 0:04:05.120 --> 0:04:08.360 like the year three thousand something, right like, would we 0:04:08.440 --> 0:04:12.440 be just that much further along as a planet or 0:04:12.960 --> 0:04:15.440 would we be nowhere? Because in a thousand years we 0:04:15.480 --> 0:04:20.000 will have already destroyed ourselves the second one. Okay, all right, 0:04:20.040 --> 0:04:22.200 So it's a good thing this happened, or we wouldn't 0:04:22.240 --> 0:04:23.920 be talking about it right now exactly. 0:04:24.120 --> 0:04:27.240 That's exactly right. So yeah, that's a really anthropic way 0:04:27.279 --> 0:04:31.240 of looking at it. Well, speaking of I bought a 0:04:31.279 --> 0:04:35.320 copy of If Anyone Builds It, Everyone Dies, the Ellie 0:04:35.400 --> 0:04:37.680 is or Yukowski Nate Sores book that just came out. 0:04:38.080 --> 0:04:39.960 Okay, and did not know about it. You say that 0:04:40.040 --> 0:04:41.680 as if it was just on the tip of my tongue, 0:04:41.680 --> 0:04:43.000 which I appreciate. No, you do. 0:04:43.520 --> 0:04:47.320 We remember I basically mischaracterized it in the Zizians episode 0:04:47.360 --> 0:04:50.080 and had that Oh yeah, okay, that book right about 0:04:50.080 --> 0:04:53.000 building AI and if anyone builds it, then we're all 0:04:53.040 --> 0:04:55.279 going to die, like just the existential threat of AI. 0:04:55.720 --> 0:04:58.480 It is really good. You could read it and if 0:04:58.520 --> 0:05:01.880 you had a a day that you could dedicate to 0:05:01.960 --> 0:05:03.960 reading it, you could read it in a day. It's 0:05:04.080 --> 0:05:07.880 really popularly written, lots of really cool anecdotes. It's just 0:05:08.040 --> 0:05:12.279 very good. So I strongly recommend that book. Great, Okay, 0:05:12.360 --> 0:05:14.880 so let's kind of just back it up a little 0:05:14.880 --> 0:05:17.480 bit and go to the previous ice ages of Wisconsinian 0:05:17.560 --> 0:05:20.680 ice Age and talk about what Earth looked like like that. 0:05:21.800 --> 0:05:25.880 Yeah, so it was. It was very icy. There were 0:05:26.000 --> 0:05:29.440 huge ice sheets covering a lot of Earth, like most 0:05:29.480 --> 0:05:33.400 of North America, northern Europe, and Asia. And as we'll see, 0:05:33.440 --> 0:05:38.320 a lot of the YDS affected the northern hemisphere much 0:05:38.360 --> 0:05:40.680 more than the southern. But also weird things happen in 0:05:40.680 --> 0:05:42.880 the southern hemisphere that don't quite jibe. That's why it's 0:05:43.200 --> 0:05:46.440 such a kind of a strange mystery. But lots of 0:05:46.440 --> 0:05:52.160 ice everywhere. We had barren planes, very harsh conditions. We 0:05:52.200 --> 0:05:54.680 had things like you know, wooly mammos like ice ice 0:05:54.760 --> 0:05:59.600 loving creatures dwelling the earth, and you know human populations 0:05:59.600 --> 0:06:03.679 that were sparse and scattered and constantly kind of moving 0:06:03.680 --> 0:06:05.160 around trying to survive. 0:06:05.320 --> 0:06:07.920 Right, And so that the Last ice Age started about 0:06:07.920 --> 0:06:10.080 one hundred thousand years ago, and it took about eighty 0:06:10.160 --> 0:06:14.159 thousand years to reach its peak point. So twenty thousand 0:06:14.200 --> 0:06:16.840 years ago it hit what's called the last glacial maximum, right, 0:06:17.839 --> 0:06:19.760 So it took eighty thousand years to get there and 0:06:19.800 --> 0:06:24.279 then ten thousand years to basically melt. It melted a 0:06:24.320 --> 0:06:29.080 lot faster than it developed. And just like right after 0:06:29.279 --> 0:06:32.480 it peaked, it just started warming up. And it took 0:06:32.520 --> 0:06:35.200 about nine thousand years and all the ice sheets, all 0:06:35.240 --> 0:06:37.479 the glaciers, all this stuff that was covering Earth and 0:06:37.560 --> 0:06:40.159 keeping it and ice age just basically went away. And 0:06:40.279 --> 0:06:43.280 Earth just blossomed into a version that we. 0:06:43.520 --> 0:06:47.560 Like, yeah, and it became, you know, not terribly unlike 0:06:47.600 --> 0:06:49.640 what we're looking at now. There was a jump in 0:06:49.680 --> 0:06:52.880 temperatures that was you know, kind of close ish to today. 0:06:53.360 --> 0:06:55.440 And this was called the and I never know how 0:06:55.440 --> 0:06:58.280 to pronounce it's a umla, is it really? 0:06:58.480 --> 0:06:58.680 Yeah? 0:06:58.720 --> 0:06:59.880 I'm that's all it is. 0:07:00.120 --> 0:07:03.120 Yes, So all of our Nordic friends, the circle with 0:07:03.160 --> 0:07:06.080 the the forward slash through or the O with the 0:07:06.120 --> 0:07:08.400 forward slash through. Yeah, that's an um lot right. 0:07:08.720 --> 0:07:11.000 Okay, I mean I guess we call it the null 0:07:11.080 --> 0:07:13.320 set because it looks like a zero with a slash 0:07:13.320 --> 0:07:14.840 through it, So call it that. I mean, we don't 0:07:14.880 --> 0:07:16.400 really call it that, but that's what it looks like. 0:07:16.480 --> 0:07:18.320 Pronounce it like that, all right? 0:07:18.360 --> 0:07:23.880 What with the oomlount, No, the null set, I would 0:07:24.000 --> 0:07:26.360 know how to do that with the umlaut. I guess 0:07:26.360 --> 0:07:31.080 my best stab would be the berling alarud interstadio. 0:07:31.440 --> 0:07:33.360 I think you nailed it, all right. 0:07:33.680 --> 0:07:36.160 A lot more rain we got to, you know, we 0:07:36.200 --> 0:07:38.720 achieved a sea level that's not what we have today, 0:07:38.760 --> 0:07:41.960 but about half of what we have today. With that rain, 0:07:42.000 --> 0:07:44.280 obviously you're going to get a lot of plants. The 0:07:44.320 --> 0:07:48.160 woodlands are thriving. Animals are now are you know, forest 0:07:48.240 --> 0:07:52.000 dwelling and walking alongside things like cave bears and wooly 0:07:52.080 --> 0:07:55.880 mammoths and things are going pretty good. We have Homo 0:07:55.920 --> 0:07:59.480 sapiens at this point, or are the only humans that 0:07:59.520 --> 0:08:02.760 are around this point, and they're like their love and 0:08:02.840 --> 0:08:05.680 life man. They're saying, all right, we can travel a 0:08:05.680 --> 0:08:08.280 little bit more and as we'll see, you know, kind 0:08:08.280 --> 0:08:12.160 of dabble stick their toe in, settling here and there. 0:08:12.760 --> 0:08:15.560 Yeah, this was actually right before. This was the point 0:08:15.640 --> 0:08:20.160 when people from Eurasia migrated into North America. So this 0:08:20.360 --> 0:08:22.280 is the point where they were cut off. They couldn't 0:08:22.280 --> 0:08:24.680 go back. There's no going back. They were in North 0:08:24.720 --> 0:08:27.080 and South America now because the Bearing Land Bridge was 0:08:27.120 --> 0:08:29.920 covered up by those rising sea levels which turn it 0:08:29.960 --> 0:08:33.160 into the Bearing Sea. And this time, so remember we're 0:08:33.160 --> 0:08:35.480 talking about this little period after the end of the 0:08:35.480 --> 0:08:39.360 ice Age, before the yd comes along, where everything seems 0:08:39.360 --> 0:08:42.000 to be going smoothly for humans. This is where we 0:08:42.040 --> 0:08:46.920 started taking our first stabs at agriculture. We're just like, 0:08:47.040 --> 0:08:49.199 let's try something new. We just came out of an 0:08:49.200 --> 0:08:51.760 ice age. Let's just get as funky as we can 0:08:51.840 --> 0:08:55.360 with it, and we're going to basically take some of 0:08:55.360 --> 0:08:57.920 that energy in that time that we dedicate to hunting 0:08:58.240 --> 0:09:01.960 and gathering and put it in to farming. I just 0:09:02.040 --> 0:09:04.320 made that word up, but let's call it that from 0:09:04.320 --> 0:09:04.600 now on. 0:09:06.240 --> 0:09:09.520 Like, what is farming? They're like, you're doing it right now, buddy. 0:09:09.559 --> 0:09:13.000 I see over there picking weeds exactly and tending to 0:09:13.040 --> 0:09:16.280 those wild plants. And that's basically the you know, kind 0:09:16.320 --> 0:09:18.679 of I guess the argument for the beginning of agriculture 0:09:18.720 --> 0:09:20.360 at least, right, Yeah, well. 0:09:20.280 --> 0:09:22.520 We basically said, that's a good looking plant. Let's just 0:09:22.559 --> 0:09:25.080 try to make that one grow as well as we can. 0:09:25.520 --> 0:09:30.160 That's right. So things are going along swimmingly, people are 0:09:30.160 --> 0:09:32.600 not moving around as much, they enjoy sitting for the 0:09:32.600 --> 0:09:36.080 first time and things like that, and then all of 0:09:36.080 --> 0:09:40.600 a sudden, the yd comes along and the glacial conditions 0:09:40.880 --> 0:09:45.040 return in the broad sense in a very quick way. 0:09:46.040 --> 0:09:48.280 I mean, how long did it take, Like, I mean, 0:09:48.280 --> 0:09:50.520 the whole thing was like a thousand years, but we 0:09:50.640 --> 0:09:53.760 reached kind of close to that last glacial maximum in 0:09:53.800 --> 0:09:55.079 about five hundred years. 0:09:55.240 --> 0:09:58.240 Yeah, I think by one hundred years it was really 0:09:58.320 --> 0:10:00.320 like in full swing. And then yeah, five hundred years 0:10:00.360 --> 0:10:02.760 is basically like the ice age is back. 0:10:03.200 --> 0:10:06.120 I wonder if they were like, hey, does anyone think 0:10:06.120 --> 0:10:07.640 it's getting colder? Right? 0:10:08.520 --> 0:10:10.200 No, just keep farming and be quiet. 0:10:10.000 --> 0:10:11.640 Right, yeah, yeah, just keep planting those plants. 0:10:11.800 --> 0:10:14.200 We should also say Kyle helped us with this, and 0:10:14.240 --> 0:10:18.080 he said that the younger driest came along and spoiled 0:10:18.120 --> 0:10:21.920 the party. That's truer than you would think, because right, 0:10:22.000 --> 0:10:25.400 before this, and that booing all a rod inner stadial 0:10:26.160 --> 0:10:28.760 was when we started making beer too, so that got 0:10:28.760 --> 0:10:29.760 disrupted as well. 0:10:30.720 --> 0:10:32.520 We'd be so much drunker today. 0:10:32.520 --> 0:10:36.080 So another reason we would have wiped ourselves out in 0:10:36.240 --> 0:10:40.520 just one global bar fight. Basically, Yeah, so this is 0:10:40.600 --> 0:10:43.840 this kicks off thirteen hundred years of really really cold 0:10:44.040 --> 0:10:47.760 weather and then all of a sudden it just stops 0:10:48.240 --> 0:10:51.680 and it comes along it like happened starting about one 0:10:51.760 --> 0:10:54.439 hundred years, five hundred years into it. It was really 0:10:54.480 --> 0:10:57.880 basically back to ice age conditions in a lot of places. 0:10:58.280 --> 0:11:01.840 But when it stopped, it swung back to nice and 0:11:02.360 --> 0:11:07.400 humid even faster. And there's actual ice cores from Greenland 0:11:07.559 --> 0:11:12.040 that show that Greenland in ten years the average temperature 0:11:12.040 --> 0:11:16.040 increased by eighteen degrees farent height ten degrees celsius. That 0:11:16.240 --> 0:11:20.040 is insane and for comparison so the global warming that's 0:11:20.080 --> 0:11:23.800 going on today that scientists are quite concerned about and 0:11:24.000 --> 0:11:29.320 thinking people as well, that's a rise of two degrees 0:11:29.360 --> 0:11:32.200 farent height, not eighteen degrees farent height. Two degrees farentheight 0:11:32.400 --> 0:11:36.280 in about twenty decades. We're talking about eighteen degrees rise 0:11:36.360 --> 0:11:39.600 in one decade. That's how fast this thing warmed up. 0:11:40.160 --> 0:11:43.360 Yeah, that's super quick. And again, you know, whenever you 0:11:43.400 --> 0:11:44.920 talk about this kind of stuff, you gotta zoom out 0:11:44.960 --> 0:11:47.120 and look at it from a sort of macro point 0:11:47.160 --> 0:11:50.320 of view. But yeah, that's super fast and got super 0:11:50.440 --> 0:11:55.280 hot and also super cold. Previously during the YDS, which 0:11:55.320 --> 0:12:02.160 was named, by the way, after flower the driest octopus octapitala. Yeah, 0:12:03.040 --> 0:12:06.120 nailed it. And the odd thing about this flower and 0:12:06.160 --> 0:12:08.199 why they named the YDS after it is that it 0:12:08.880 --> 0:12:12.560 thrives in cold Arctic regions. Is one of these flowers 0:12:12.559 --> 0:12:15.040 that loves the ice kind of the mountains of Scandinavia. 0:12:16.000 --> 0:12:20.079 In the late eighteen hundreds, like the eighteen seventies, Swedish 0:12:20.160 --> 0:12:24.160 scientists were studying clay deposits that they discovered, and they 0:12:24.160 --> 0:12:27.920 discovered this flower and they were like, this flower shouldn't 0:12:27.920 --> 0:12:31.199 be here between these layers of clay. It was deposited 0:12:31.200 --> 0:12:34.040 by melting glaciers. But like, none of that makes any sense, no. 0:12:34.080 --> 0:12:36.840 Because you've got clay from melting glaciers above it and 0:12:37.040 --> 0:12:40.160 clay from melting glaciers below this flower, and this flower 0:12:40.679 --> 0:12:44.440 thrives in temperatures where the glaciers are not melting at all, 0:12:44.640 --> 0:12:47.320 So it was a huge mystery. And then what made 0:12:47.360 --> 0:12:49.320 it even more mys serious is that was confirmed by 0:12:49.400 --> 0:12:53.440 other clay deposits elsewhere in Scandinavia. So there was definitely 0:12:53.480 --> 0:12:56.400 something weird going on. And they named it younger Dryis 0:12:56.400 --> 0:12:59.520 because there actually have been older dryis before. Yeah, that 0:12:59.640 --> 0:13:02.640 was not nearly as much of a bizarre freak as 0:13:02.640 --> 0:13:03.880 the Younger Dryas was. 0:13:04.440 --> 0:13:07.559 That's right. So we got the O D, we got 0:13:07.559 --> 0:13:10.559 the Y D. Should we take a break? Yeah, that 0:13:10.600 --> 0:13:12.880 sounds like a pretty good time for a break. Yeah, yeah, yeah, 0:13:13.600 --> 0:13:15.720 all right, we'll be right back. 0:13:19.760 --> 0:13:29.200 Jok, Mad, Josh, stop, you should. 0:13:29.120 --> 0:13:54.360 Know, so, Chuck, we've been talking like pretty big shots, 0:13:54.360 --> 0:13:55.800 pretty confident here right. 0:13:56.000 --> 0:13:58.040 Now, a couple of tough guys exactly. 0:13:58.160 --> 0:14:00.439 And the reason why we're doing that is because of 0:14:00.600 --> 0:14:05.840 ice core samples a lot from Greenland, also from Antarctica, 0:14:06.480 --> 0:14:10.960 and sedimentation from high altitude European lakes. That's why we're 0:14:11.040 --> 0:14:12.320 talking so tough right now. 0:14:13.000 --> 0:14:15.800 Yeah, And those are big deals. You can find out 0:14:15.800 --> 0:14:18.640 a lot from an ice core. You can find out 0:14:18.640 --> 0:14:22.360 like basically what it accumulated there, like stuff that the 0:14:22.400 --> 0:14:25.960 wind blew in there from other places. You know, they've 0:14:26.000 --> 0:14:29.120 got these little little bubbles in that ice, and you 0:14:29.120 --> 0:14:32.360 can trace gases even that were present back then and 0:14:32.520 --> 0:14:35.000 compare to like other parts of the world at that time, 0:14:35.040 --> 0:14:36.840 and like, oh, well they have these gases here, we 0:14:36.880 --> 0:14:40.360 have this sediment here, We have a distinct lack of 0:14:40.440 --> 0:14:43.720 pollen for this period here, which means like probably a 0:14:43.720 --> 0:14:46.240 lot of plant life was killed off and stuff like that. 0:14:46.840 --> 0:14:49.360 And then the lake stuff is super valuable too, right. 0:14:49.680 --> 0:14:53.760 Yeah, because constantly sediment is accumulating at the bottom of 0:14:53.760 --> 0:14:56.320 a lake, and very similar stuff's getting trapped down there, 0:14:56.360 --> 0:15:00.640 like air bubbles, soot, pollen, all that stuff, and it 0:15:00.760 --> 0:15:03.720 just gets deposit a year after year, and you can 0:15:03.720 --> 0:15:05.960 actually date that stuff. You can take a sample of 0:15:06.000 --> 0:15:08.760 a lake bottom and date that and then see what 0:15:08.880 --> 0:15:11.360 was going on around the lake at that time too. 0:15:11.840 --> 0:15:15.240 And lakes are advantageous because they're all over the world. 0:15:15.600 --> 0:15:18.720 Ice shelts and glaciers are not all over the world, 0:15:18.760 --> 0:15:21.600 so you're limited from where you can take ice cores. 0:15:21.920 --> 0:15:24.360 And then also lakes can last like thousands of years, 0:15:24.400 --> 0:15:27.720 whereas if you're reading tree rings, you're reading maybe decades, 0:15:27.760 --> 0:15:30.440 maybe a century or two worth. A lake it's going 0:15:30.480 --> 0:15:32.280 to give you way more than that. So it's pretty 0:15:32.320 --> 0:15:34.920 clever the way that they can take this stuff not 0:15:34.960 --> 0:15:38.160 only figure out when this sediment deposit or this ice 0:15:38.200 --> 0:15:43.360 deposit was put down, but also like a lack of 0:15:43.440 --> 0:15:46.160 pollen or what type of pollen means for like the 0:15:46.200 --> 0:15:49.000 world at large at the time. I just think that's 0:15:49.040 --> 0:15:51.800 pretty cool that humans are able to do that, and 0:15:51.840 --> 0:15:53.440 they don't seem to just be making this. 0:15:53.520 --> 0:15:58.480 Up, you know, a very niche nerdy stuff. You should know. 0:15:58.480 --> 0:16:02.640 A T shirt could just be uh lake bottom greater 0:16:02.760 --> 0:16:04.280 than simple tree ring. 0:16:05.240 --> 0:16:08.160 That's a super nerdy. I think that would actually offset 0:16:08.240 --> 0:16:11.680 the be dumb and happy one that you got generated. 0:16:12.080 --> 0:16:14.080 I think so. But just you know, you walk around 0:16:14.120 --> 0:16:17.080 like Comic Con and somebody will say, I know exactly 0:16:17.160 --> 0:16:18.600 what you're doing, buddy. 0:16:18.240 --> 0:16:20.840 And they'll they'll just silently walk past you and give 0:16:20.880 --> 0:16:23.600 you the high five and the low five without stopping. 0:16:23.600 --> 0:16:25.720 Right, but it'll be a sort of a nerdy. They'll 0:16:25.720 --> 0:16:28.240 miss the high five won't be quite right. They'll try 0:16:28.280 --> 0:16:29.840 and fist bump you when you put up your hand or. 0:16:29.840 --> 0:16:32.680 Right, or they lock fingers with you on the lof 0:16:33.040 --> 0:16:34.200 and you guys keep trying to. 0:16:34.160 --> 0:16:37.680 God, that's gotta be the worst. I thought the fist 0:16:37.720 --> 0:16:40.640 bump in the hand together was the worst. But when 0:16:40.680 --> 0:16:43.440 you high five and someone holds on and locks fingers. 0:16:45.680 --> 0:16:46.720 Yeah, so weird. 0:16:47.720 --> 0:16:50.400 Oh goodness, I don't know why I think of Oprah 0:16:50.400 --> 0:16:52.600 Winfrey when does she? Has she ever done that? 0:16:52.840 --> 0:16:54.880 I think she likes to raise people's hands, like they 0:16:54.960 --> 0:16:56.600 just want a boxing match or something. 0:16:58.440 --> 0:17:02.000 All right, so we're settling into the YD. I mentioned 0:17:02.000 --> 0:17:04.879 earlier that the northern hemisphere was one that was really 0:17:05.160 --> 0:17:11.119 affected the most, especially around the North Atlantic. The southern hemisphere. 0:17:11.119 --> 0:17:13.919 We'll talk about some weird abnormalities there as well. But 0:17:14.880 --> 0:17:17.840 these ice sheets advanced across the Arctic seed just like 0:17:17.880 --> 0:17:22.600 they did during the Old LGM, the last Glacial maximum? 0:17:22.680 --> 0:17:23.920 Is it glacial or glacial? 0:17:24.680 --> 0:17:26.680 Oh? I don't know. It depends on whether you say 0:17:26.680 --> 0:17:27.880 potato or patata. 0:17:27.960 --> 0:17:31.520 Yeah, I guess. So the Rockies here and what would 0:17:31.560 --> 0:17:36.399 later be the United States expanded, the Alps expanded. They 0:17:36.480 --> 0:17:41.600 found very weird things like penguin like creatures in southern Italy. 0:17:42.960 --> 0:17:45.159 Like things were getting really out of whack again, and 0:17:45.200 --> 0:17:48.040 everyone back then was like WTF. 0:17:47.720 --> 0:17:50.879 Yeah, and the like, even if you weren't living in 0:17:50.920 --> 0:17:54.480 an iced over area, you know, basically due south of 0:17:54.560 --> 0:17:58.240 that was tundra, like so western Europe, which is nice 0:17:58.240 --> 0:18:00.840 and verdant in lush right now, So it was tundra 0:18:00.960 --> 0:18:03.639 at the time. You got grasses, maybe a fox or 0:18:03.640 --> 0:18:05.920 two if you're lucky and you're bored just looking around, 0:18:05.920 --> 0:18:08.560 because it's not the most pleasant landscape to look at. 0:18:09.080 --> 0:18:11.359 I remember humans are running around at this time. I 0:18:11.400 --> 0:18:16.280 think we shrunk tremendously as a population, down to maybe 0:18:16.840 --> 0:18:19.840 the highest estimate I saw was around ten million people 0:18:20.560 --> 0:18:22.639 across the entire planet at this time. 0:18:23.320 --> 0:18:24.000 That sounds nice. 0:18:24.000 --> 0:18:29.240 Actually we kind of talk about Elba room. But all 0:18:29.280 --> 0:18:33.040 the plants and animals that had started to thrive in 0:18:33.080 --> 0:18:35.200 the middle in between the ice age and the YD 0:18:35.960 --> 0:18:39.000 they died back. And all the animals and plants that 0:18:39.040 --> 0:18:43.600 had died back during that innerstodial period they came roaring 0:18:43.680 --> 0:18:46.160 back and they were like, we loved we love the YD. 0:18:46.400 --> 0:18:47.320 We're happy again. 0:18:48.119 --> 0:18:52.920 Yeah, for sure. I mentioned the pollen retreating being evidence 0:18:52.960 --> 0:18:55.359 of like you know, the tree cover going away, and 0:18:55.400 --> 0:18:57.840 they found evidence of that an ice core once again. 0:18:58.440 --> 0:19:01.600 This is in the Hulu Cave and chin and it showed, 0:19:01.760 --> 0:19:04.919 you know, a drastic reduction in tree pollen, which you know, 0:19:05.000 --> 0:19:08.119 basically you can infer that like, yeah, a lot of 0:19:08.160 --> 0:19:10.400 trees died out during this icy period. 0:19:10.240 --> 0:19:12.040 Right, And from that you can also infer that there 0:19:12.080 --> 0:19:15.320 was probably less rain because trees helped generate clouds and 0:19:15.400 --> 0:19:20.040 they also helped keep the planet warm. So it was 0:19:20.520 --> 0:19:23.919 obviously a lot colder and a lot drier. That was 0:19:24.000 --> 0:19:28.919 the two characteristics of the YD And then, like you said, 0:19:28.960 --> 0:19:33.640 the southern hemisphere experienced something radically different, right, So remember 0:19:34.560 --> 0:19:38.080 northern Europe is covered in ice again, it's tundra right 0:19:38.160 --> 0:19:41.120 below that. And then if you go down to Antarctica, 0:19:41.520 --> 0:19:44.639 they basically hand you like a lay and a Hawaiian 0:19:44.720 --> 0:19:46.680 shirt and like my tie. 0:19:47.760 --> 0:19:50.919 Yeah, it's so crazy. When I was going through this stuff, 0:19:51.000 --> 0:19:54.359 that to me was like the big reveal. I mean, 0:19:54.400 --> 0:19:56.280 I would I'm a big dummy when it comes to 0:19:56.280 --> 0:19:57.800 this stuff. So I just figured that would have been 0:19:57.840 --> 0:20:02.440 even colder and even worse. But tmperatures actually rose in 0:20:02.520 --> 0:20:05.040 the Southern Hemisphere, and a lot of the Southern Hemisphere 0:20:05.080 --> 0:20:09.240 became warmer and wetter, and the sea surface temperatures increased 0:20:09.240 --> 0:20:13.680 in the Caribbean and the tropical Pacific. In the mountains 0:20:13.680 --> 0:20:16.159 of New Zealand that saw warmer conditions, so it was 0:20:16.240 --> 0:20:18.960 like everything was kind of upside down all of a sudden. 0:20:19.240 --> 0:20:22.240 Yeah, but you also mentioned earlier that it didn't happen 0:20:22.280 --> 0:20:24.600 there were weird pockets here there, which also goes to 0:20:24.720 --> 0:20:28.159 underscore how bizarre the younger dryest was like, there's a 0:20:28.200 --> 0:20:32.919 basin around Venezuela and it actually had temperatures drop. So 0:20:32.960 --> 0:20:36.280 this is the southern hemisphere, right, It saw a temperature 0:20:36.320 --> 0:20:39.400 drop of three degrees celsius five and a half degrees farentheight. 0:20:39.920 --> 0:20:42.600 And every time I see something like that, I'm like, so, like, 0:20:42.680 --> 0:20:45.359 that's not that big of a deal. Right, It turns 0:20:45.359 --> 0:20:48.159 out it is a really big deal. Even though to 0:20:48.280 --> 0:20:53.040 you an average winter temperature of fifty five going down 0:20:53.080 --> 0:20:58.120 to fifty doesn't sound all that bad, but climatologically speaking, 0:20:58.640 --> 0:21:03.720 any change in temperature, even by half degrees has really 0:21:03.840 --> 0:21:07.760 huge weather consequences oversay the course of a year. So 0:21:08.040 --> 0:21:10.800 in this case, dropping by three degrees celsius for five 0:21:10.840 --> 0:21:13.560 and a half degrees farentheight, it might not have seen 0:21:13.600 --> 0:21:17.399 that much temperature wise over an average winter, but it 0:21:17.480 --> 0:21:20.840 also opened up the door for way more freak weather, 0:21:21.320 --> 0:21:24.119 so they might have gone from like no blizzards whatsoever. 0:21:24.280 --> 0:21:27.280 Maybe one blizzard a year, two three blizzards a year, 0:21:27.480 --> 0:21:30.840 and that definitely impacts local conditions in the life there. 0:21:30.920 --> 0:21:33.320 So it makes a really big difference, even when you 0:21:33.359 --> 0:21:36.600 see little changes to average temperatures. 0:21:36.920 --> 0:21:40.920 Yeah, for sure, there were likely some animal extinctions happening. 0:21:42.160 --> 0:21:44.480 You mentioned the amount of humans, which was at a 0:21:44.880 --> 0:21:46.840 you know, probably at an all time high at this point, 0:21:47.480 --> 0:21:51.520 started going back lower and lower. Their available food was 0:21:51.960 --> 0:21:55.360 getting slimmer and slimmer. We mentioned they were dabbing their 0:21:55.400 --> 0:21:58.280