What Was the Earth Like after Dinosaurs? The Ice Age

the geological history of the earth Bears the traces of many global climate changes variations in temperature radiation levels and the composition of the planet's atmosphere have proved to be a verdict for some species and an evolutionary impetus for others some major extinctions wiped out up to 90 percent of the species of our time bringing life on the planet to the brink of Extinction over the last 500 million years there have been five such Global catastrophes and right now according to statistics a sixth one is a progress and the fastest known in terms of running its course what is happening on our planet and why is its biosphere degrading so rapidly let's try to find out [Music] the earth's climate like that of any other Celestial body is determined by a combination of a huge number of factors some of these are external such as variations in cellular activity or the rhythmic deformation of the planet's orbit others are caused by the Earth itself to answer the question of what is happening now and what to expect in the future we need to travel back tens of millions of years to find out how the face of our planet was changing and what factors were influencing climate change right now you're looking at a graph on the screen that shows the change in the average temperature of our planet over 500 million years by putting together data from excavations around the world scientists have been able to accurately determine the earth's climate in each period looking at the big picture it is easy to see that long and hot intervals were followed by shorter periods of cooling during these periods called ice ages the climate was drier temperatures were lower and ice caps were building up at the pearls of our planet just the way they look now each Global change in the average temperature of our planet was a trial for its inhabitants and not everyone made it foreign approximately 66 million years ago a huge 10 kilometer asteroid is rapidly approaching our planet just minutes later it pierces the atmosphere and crashes to the surface [Music] a definite explosion of the power of millions of thermonuclear bombs shakes the Earth [Music] the violent Shockwave crashes and blasts away rocks forming a gigantic crater about 180 kilometers across many of the rocky fragments are thrown out of the atmosphere into space they later fall back on the planet thousands of kilometers from the explosion causing widespread forest fires [Music] the shock wave is believed to have traveled around the entire planet causing earthquakes in its furthest reaches while a gigantic tsunami destroyed the coasts of continents they penetrated hundreds of kilometers Inland ramming everything in their path 15 trillion tons of suit and dust were sucked into the air and blown across the Earth for many years our planet received far less sunlight than usual causing a dramatic Cooling according to research for at least 16 years after the disaster the average temperature of the planet remained around 3 degrees Celsius which is 11 degrees lower than it is now as a result most terrestrial and aquatic plants became extinct causing a massive famine among animals almost all creatures weighing over 25 kilos including flightless dinosaurs and Aquatic lizards vanished from the face of the Earth some did not survive the catastrophe itself others fell victim to its consequences thus began the cenozoic a new era in the history of our planet for the next 10 million years referred to as the paleoc in Epoch the Earth was recovering from this cataclysmic event the volcanic ash clouds gradually dissipated and temperatures Rose rapidly to comfortable levels step by step life repopulated the baron expresses of the planet but this time it was completely different species flowering plants mammals and birds the end of the paleocene was marked by a rapid rise in temperature largely attributed to tectonic activity during this period volcanic eruptions in the North Atlantic Ocean released great amounts of methane and carbon dioxide into the atmosphere with concentrations as high as 2 000 parts per million five times higher than today's levels this warming is considered to be the beginning of a new Epoch called the air scene it started about 56 million years ago and persisted for about 22 million years during this time the average temperature of our planet was noticeably higher than it is today at times as high as 28 degrees Celsius paleontological evidence suggests that during the year scene the climate of most of the land was close to that in the tropics and dense broad-leaved forests reached as far as the polar circles at the time palms and heat-loving reptiles are known to have inhabited the area of today's Europe the main reason for this is thought to be the favorable location of the continents at that time North and South America were separated by broad Strait African Eurasia had not yet made contact either equatorial currents and Atmospheric currents were therefore free to travel across the Earth Distributing heat relatively evenly over it in addition the abundance of decomposing organic matter maintained high levels of carbon dioxide in the atmosphere which also helped the climate to remain warm thanks to the mild conditions and abundance of food mammals of this time experienced growth from Tiny marsupials hiding in Burrows and Treetops to Majestic Giants weighing tens of tons it was also during this period that the ancestors of most of today's mammals the ancient primates cetaceans and rodents appeared however the face of the Earth continued to change slowly but steadily the spread of the Aquatic Fern are Zola in Northern Waters led to a gradual drop in atmospheric carbon dioxide levels and a gradual Cooling and around 34 35 million years ago there is an unexpected sharp break in the temperature graph during this period on the border between the ear scene and oligacy in epochs a number of very important events took place first the Collision of the continents caused Majestic mountain ranges to rise to the heavens such as the Himalayas the Alps the carpathians and the Appalachian Mountains significantly affecting air currents in the atmosphere secondly analysis of the fossils showed that it was at this time that a new type of photosynthesis called C4 began to spread actively among plants this turned out to be much more efficient than the previous type of reaction and this gradually led to an increase in atmospheric oxygen concentration by two to three percent up to today's levels the carbon dioxide content on the other hand dropped markedly resulting in a weakening of the Greenhouse Effect and a global drop in temperature thirdly this mess between South America and Antarctica was broken up by the movement of tectonic plates as a result the forces of inertia caused by the Earth's rotation formed a closed ocean current that enclosed the southernmost continent of our planet in a curl drain their currents also formed an impenetrable barrier preventing Warm Winds from entering Antarctica as a result temperatures on the continent began to drop rapidly and by the end of the Paleo Gene its green forests had been permanently replaced by fast growing glaciers all of these events heralded the beginning of a new Epoch The oligar Scene It persisted for about 11 million years during which the climate of our planet was relatively steady dry and cool and at the same time noticeably warmer than today this tendency continued into the beginning of the next Epoch the Maya scene however at about 14 million years ago on the graph we see another abrupt cooling it is called the middle myocene disruption and is thought to have been caused by a combination of two factors first of all the Earth in its orbital motion once again entered the code phase of the so-called milankovic Cycles melankovic Cycles are periodic fluctuations in the amount of solar energy reaching our planet depending on changes in the position of the Earth's axis and its orbit when the eccentricity of the Earth's orbit reaches higher values and the winter solstice coincides with the perihelion the planet's climate becomes significantly cooler this is what happened 14 million years ago during the middle myocene disruption as a consequence of this cooling forests declined getting largely replaced by savannas and steps this stimulated the spread of flowering plants using C4 photosynthesis as more resilient and competitive ones as a result the level of carbon dioxide in the planet's atmosphere drastically dropped leading to even more cooling to understand the natural processes of this period it is worth remembering that the Savannah and similar biomes are highly biologically productive systems one square kilometer of Savannah produced up to 1500 tons of biomass a year almost the equivalent of living creatures inhabiting this area highly nutritious grasses with short lifespans nourished herbivores ensuring rapid recycling of nutrients including carbon as a consequence The increased Savannah area helped to lower concentrations of carbon dioxide in the atmosphere and lead to a further drop in temperature as a result in the course of several million years the average global temperature dropped by about 6 degrees from 17 degrees Celsius to 11 degrees making most of the megaphone of the previous period extinct the most notable animals of this time when humorous drunked animals as well as the prehistoric ancestors of Horses The hipparians the largest carnivores were amphis ionidi and hyenodons which weighed up to half a ton [Music] following the graph it is easy to see that starting with the middle myocene disruption the Earth cooled down smoothly and inexorably the consequence was a rapid growth of glaciers in the second polar regions of the planet which began about 8 million years ago the Antarctic ice sheet began to grow rapidly a non-melting polar cap formed in the Arctic Ocean and the forests of Greenland began to disappear rapidly giving way to glaciers however with a main ordeal was yet to come around 2.6 million years ago the temperature drop noticeably accelerated at about this time the movement of the continents and a drop in the global sea level led to the formation of the Isthmus of Panama which firmly sealed off the strait between North and South America as a result the warm equatorial Waters of the Pacific could no longer mix with the Atlantic currents and the Atlantic temperatures gradually began to fall in addition the Rocky Mountains having grown considerably by this time presented an obstruction to warmer air currents further disrupting the circulation of heat around the planet as a consequence the seasonal temperature variations over much of the land became even more pronounced and the rate of Glacier growth increased substantially around the same time the so-called gorse matiama reversal occurred during which the Earth's magnetic pearls reversed once again fifteen thousand years the protective field of our planet was about four times weaker than it is today leading to the extinction of several families of marine animals and algae this event allowed us to speak at the beginning of a new geological period the pleistocene glacias became its characteristic feature they would Advance sometimes occupying up to 30 percent of the land's surface then Retreat beyond the polar Circle but they never disappeared completely the first half of the pleistocene was remarkably consistent with warming and cooling periods occurring every 41 000 years this periodicity coincides very closely with the milankovic cycles so it is thought that it is these natural fluctuations in the Earth's orbit that caused it the movement of glaciers and climatic shifts inevitably affected the Flora and Fauna reshaping the planet's inhabitants global cooling forced many herbivores to put on a furry coat and grow larger to withstand the cold thus mammoths and mastodons Woolly rhinoceroses and other herbivorous Giants appeared carnivores were forced to follow suit North America for example was home to the great polar bear a fearsome Beast estimated to weigh up to 1 200 kilograms three to four times more that is today's relatives a little further south lived the so-called dire wolves which were about twice the size of today's wolves it has been suggested that these Predators hunted in packs of three or four and thanks to their strength and coordinated action were capable of driving and killing bison meanwhile around 1 million years ago the periodicity of Glacier onset was disrupted the cooling Cycles became irregular and their duration increased substantially to an average of one hundred thousand years as a consequence the temperature contrast was more dramatic and the thickness of glaciers varied more as well this transformation is called the middle pleistocene transition and its causes are not yet fully explored the most feasible version is that when moving earlier glaciers wiped away the layers of regolith that covered the bedrock in the northern latitudes the new glaciers froze over less slippery rocks such as granites and basalts thus disrupting the established cyclicity another reason could have been the blocking of the Bering Strait caused by a drop in the sea level and Rising glaciers this event occurred about nine hundred thousand years ago and caused curled water from the Pacific Ocean to stop flowing into the Arctic Ocean this resulted in a further drop in temperature and increased Cooling also throughout the pleistocene the ancestors of modern humans gradually spread across the planet researchers have documented traces of several Global migrations and many smaller ones as nomadic gatherers and Hunters these ancient tribes explored new lands competing into breeding and dividing giving rise to dozens of different forms some left behind only bones and abandoned sights others were much more fortunate they were to become the ancestors of all modern humans the late pleistocene also known as upper blistocene began 129 000 years ago and continued for 117 000 years it was a time of Maximum Cooling and the largest glaciers in a fierce struggle for survival the crowmanian ancestors of modern humans wiped out or assimilated all other human communities in an effort to escape the dangers ancient tribes spread Beyond Eurasia and Africa thanks to a land passage in what is now the Bering Strait they entered North America in several stages thus becoming the ancestors of numerous Indian tribes around the same time a few thousand kilometers further south a drop in sea level opened away to Australia and so around 50 000 years ago humans arrived in this isolated world too lacking systematic knowledge of the environment a prehistoric man was unable to comprehend the long-term consequences of his actions and treated nature in a highly exploitative manner Australia appeared as a green Paradise full of easy prey unused to humans the slow and not very smart giant marsupials such as diprotodons and polycastes proved unable to stand up to the new predator which was smart and came in big numbers just 10 000 years later most of Australia's animals larger than 45 kilograms were exterminated to hunt them Aboriginal Australians actively torched vegetation causing Fierce forest fires most of the game hunted in this way was lost and the scorched out area was left with a semi-desert of sparse grass and scrub at best Australia's climate is arid and the soil is not very fertile so once a forest is destroyed it cannot regenerate on its own eventually when sea levels rose again Australians were trapped on a parched continent unable to feed their expanding population after violent fighting and prolonged famine the population was reduced to Optimum levels as it were but the path to civilization was closed to the local tribes the blister scene is thought to have ended about 11 700 years ago with the end of the last cooling period glaciers retreated sea levels Rose by 35 meters and some regions of the earth developed distinctive previously unseen biomes the best known of these were the Nile Valley and Mesopotamia but in fact there were many more the abundance of water and fertile soil was favorable for grains the seeds of which are highly nutritious the tribes living nearby no longer had to roam in search of food the gifts of nature were plentiful thus non-migratory or sedentary Gathering Lifestyles established themselves to later evolve into farming the peculiarity of Agriculture is that its products need to be processed and stored this nade stimulated the development of construction and pottery followed by metal working this is how the history of ancient civilizations began technology gradually became more sophisticated and human impact on the environment increased deforestation and plowing irrigation and drainage toxic handicrafts and urban growth gradually degraded the environment in the vicinity of human settlements for a long time however these changes were localized and took centuries to become irreversible this began to change rapidly in the 18th century with the start of the Industrial Revolution the ever-increasing number of factories led to a dramatic rise in carbon dioxide emissions sulfur oxides and other substances were released into the atmosphere as well reacting with water vapor and forming strong acids these aggressive compounds settled and accumulated in soils and bodies of water gradually making the lattice uninhabitable second half of the 20th century saw a particularly rapid rise in emissions tens of thousands of power plants and factories sprang up around the world and Rising living standards and technological advances led to motorized transport becoming widespread the passenger car may not seem to produce much waste the truth is that it emits an average of 15 kilograms of carbon dioxide per day it adds up to five and a half tons a year and if we consider that there are about a billion cars and 400 million trucks on the planet at the moment it is obvious that the total amounts to billions of tons also bear in mind thermal power plants and factories which contribute even more to the pollution of the planet in 2022 humans would have emitted about 38 billion tons of carbon dioxide into the atmosphere one might sometimes hear that this amount is minuscule compared to volcanic emissions but this is a dangerous misconception if you look at the scientific data you will find that volcanoes ejects a mere 260 million tons of carbon dioxide into the atmosphere each year about 150 times less than the human impact if we look at the graph of atmospheric CO2 levels we'll see that they have already reached 400 parts per million which is about 35 percent higher than in the entire history of mankind the last time carbon dioxide levels in the Earth's atmosphere were close to this was about 5 million years ago before the global Ice Age [Music] and worst of all the figure has been reached in less than a hundred years with the increase still in progress what threat does this process pose first and foremost Rising global temperatures will cause glaciers to melt and this is already happening Greenland's largest glacier jakobshaven for example has increased its rate of melting fulfilled since the turn of the century every year its Edge Retreats three to seven kilometers inland the process has slowed somewhat in recent years but scientists believe it is a temporary spite also warming is already causing the permafrost to melt this makes many settlements and Northern latitudes uninhabitable and marine fisheries are severely affected by the unstable ice cover it should be remembered that permafrost is a gigantic planetary refrigerator in which billions of tons of organic matter is Frozen Once melted it will begin to decompose transforming into carbon dioxide and methane thus accelerating the warming further calculations show that a fall of the Earth's size caps were to melt the sea level would rise by 66 meters cities such as New York Saint Petersburg Shanghai London and many others will be partially or completely flooded entire countries and regions such as the Netherlands Polynesia or the Amal Peninsula will disappear millions of square kilometers of coastal land will be submerged and fertile land and human settlements there will be destroyed forever rapid warming will lead to the degradation of many areas forest fires will increase and deserts will grow even larger a combination of these factors will inevitably lead the world into a new Global Extinction and it would have begun by now over the last 500 years around a thousand species of large animals have disappeared from the face of the Earth more than 35 000 species of vertebrates insects and land plants and are threatened with Extinction including forty percent of all amphibians and 25 percent of mammal species these include ones important to humans plants such as bananas and species such as honeybees their demise could change our world forever and not for the better at all the modern humans imagine themselves to be wise and civilized yet at times behave even more recklessly than prehistoric humans unreasonable ambition and the pursuit of profit of power have repeatedly led to environmental disasters showing that the modern man is not far removed from the prehistoric Australian Aborigines who destroyed the flourishing land they had inherited with their own hands if we do not learn to take care of our planet will end ignominiously within it and we will only dream about distant Stars dear friends the climate change issue inevitably affects each and every one of us that is why feel free to express your opinion in the comments below it has taken two long months of energy consuming efforts to make this video and we hope you enjoyed it if you feel strongly about the issues raised share it with your friends and like it if you feel it was worth watching thanks to your support more people will find out about it and perhaps it will make the world a tiny bit better let's keep in touch foreign

Channel: Kosmo

Views: 306,898

Keywords: earth, dinosaurs, humans, earth after dinosaurs, earth's climate, global warming, dinosaurs' extinction, extinctions, prehistoric earth, continents, earth's temperature changes, cenozoic, what the earth used to be like, ice age, global cooling, early human migrations, planet, antarctica, who was around after dinosaurs, quaternary, human evolution, earth's climate in the past 500 mln years, earth's temperature graph, end of the world, earth's future, kosmo, film, video, facts, science, life

Id: NSB8nKVTqxE

Length: 29min 47sec (1787 seconds)

Published: Sat Apr 08 2023