one of the i guess stranger or slightly scarier conclusions proposed by the scientists in the study is that a lot of the signs we see in the geological history of the planet kind of resemble what we are now observing in 00:08:49 the anthropocene the period when humans started to dominate the globe or basically how the modern climate change to some extent actually resembles a lot of sudden changes that did happen in the last few millions of years with one 00:09:03 specific type of an event currently still unexplained by scientists often referred to as hyperthermals the sudden increase in temperature that usually lasts for a few thousand years but happens in a very short period of time 00:09:15 and currently doesn't have a very definitive explanation but one very well known example we explored in the past in one of the videos should be in the description known as p-e-t-m paleocene using thermal maximum the event that 00:09:28 happened approximately 55 million years ago when the global temperature suddenly increased by 5 to 8 degrees celsius or 9 to 14 degrees fahrenheit just to then drop suddenly within a few thousand years and there's been quite a lot of 00:09:41 explanations for what might have happened maybe an asteroid collision that released huge amounts of co2 gas or a lot of other gases that usually warm up the planet maybe volcanic eruptions doing the same but at the moment there's 00:09:53 just not enough clear evidence specifically craters or any volcanoes that were produced during this time to suggest any specific explanation on the other hand all of these observations kind of resemble what's happening to the planet right now as well and so trying 00:10:06 to figure out exactly what caused these warming conditions is one of the potential ways we could start assessing the hypothesis and try to answer these some of the difficult questions also likewise any kind of alloying industrial 00:10:17 civilization should maybe produce very similar effects on their planet as well at least that's what the modern science expects but what are some of the questions we can ask ourselves in regards to the history of our planet in 00:10:29 order to see how viable the hypothesis is well first of all generally speaking the geological record of our planet is usually very incomplete and it becomes even more difficult to study it as you go back in time for example today we 00:10:42 know that only about three percent of the entire surface of the planet has any kind of urban activity on the surface or basically anything that would potentially resemble modern technology and so the chance for a lot of these cities to survive for thousands or even 00:10:55 millions of years is exceptionally low which also means that within just a few thousand years the chance for discovering these techno fossils for some future humans living here is also going to be pretty low as well you can 00:11:08 kind of see that there are some bottles here and a lot of other leftovers but all this is going to disappear in time turning into nothing but almost completely indistinguishable sediment and for any major city to leave any mark 00:11:20 inside the sediment it really depends on where it's located if it's located on the subsiding plate it might eventually become sediment and get locked inside rock leaving behind certain marks but if 00:11:31 it's on the rising plate or if it's somewhere in the middle everything here might eventually be eroded with time by different types of rain and wind especially as the rain becomes more acidic leaving pretty much nothing 00:11:43 behind on the other hand when it comes to things like for example dinosaur fossils we usually discover one fossil for every 10 000 years with the footprints of dinosaurs being even more rare but even though humans have been on 00:11:56 the planet for at least 300 000 years the civilization that we're used to has only been around for just over a few hundred years and technically even less than that and so the chance for something from our modern civilization 00:12:09 to turn into a fossil that can be discovered in the future is actually super low and so right now there's a really big chance that after a few million years everything we take for granted is going to look like this and 00:12:21 so the natural question here is how do you then tell if any intelligent species ever existed on the planet like we do right now well we might be able to distinguish certain sedimentary anomalies even present in the sediment 00:12:34 today and then combine this with observations of various hyperthermals or any other major changes in the temperature that don't seem to have any other explanation for example all the technofossils are going to leave behind 00:12:46 a very specific isotopic ratio that's extremely difficult to find in nature including of course residues of carbon that doesn't exist in nature such as various microplastics these should linger for quite a while there should 00:13:00 also be geological record of a major extinction event that doesn't really have any good explanations also signs of unusual chemicals that are generally not produced in nature either for example things like cfcs or more 00:13:13 specifically various types of transuranic isotopes from nuclear fission which obviously all the chemical signs we're currently living on the planet by doing a regular stuff 00:13:24 by being ourselves and so we kind of expect something similar could have happened in the past there could have been another species that was basically exploiting the planet and as a result left some signs of this in the 00:13:37 geological record but that's of course assuming that any civilization is going to have a lot of very specific needs in terms of energy and a lot of civilizations are going to eventually result in similar types of pollution 00:13:49 naturally a pretty big assumption but it's really the only assumption we have right now in order to figure out if this hypothesis has any merit but even here there's still a major problem if this type of a civilization has not existed 00:14:02 for longer than let's just say a few hundred years the chance for it to even leave any kind of a mark and that includes the fossil mark is still pretty low and even things like microplastics or things like transuranium elements 00:14:15 might have already mixed with a lot of other stuff or disappeared completely especially if this happened a long time ago and so if these ancient civilizations ever existed and if they managed to somehow change the planet in the past the signs of their existence 00:14:28 would still be extremely difficult to discover with the only signs left after millions of years really just being various types of isotopes that could still be out there in the sediments on the planet