I get just as excited watching the Nova intro as I do a 20th Century Studios or Universal or Columbia logo. I just know it's going to teach me something I never knew, and new knowledge is just another piece of the infinite puzzle.
I cut my TV documentary teeth on NOVA! I've been hooked since the first episode in '74, and love all the documentary content PBS gives us!! Thank you so much for NOVA full episode docs and may I request BBC's "How to Grow A Planet" narrated my Dr. Iain Stewart please? ❤😀🙏
Missing pull tabs on them PBR's......more like 70's. I grew up in the 80's and as a kid I remember the big deal it was when they switched from pull tabs on cans to the pop tops where the tab stayed attached to the tops. That was a huge deal when it came out...in the 80's so this doc is dated in the 1970's.
@@murdockdacoon2055 really …. Wow 😯 it looks too good for 70’s but point taken 👍🏽 It was genuine entertainment and educational then …. Now so much drivel out there! Bring back VHS 😊
It's amazing to watch these older documentaries. The detail of the understanding of the past was reasonable accurate but crude. The amount of studies and detail that have been added since this documentary was produced is astounding.
I was just thinking the same thing. It was made before geologists learned of snowball earth or any of the early mass glaciations. And the description of the Earth forming in an inferno of molten rock and gas with an image of Hawaiian lava bujbbling away gives the gist, but of course we now know a good deal more from the Theia collision to Jupiter wandering in and wandering out again.
From Martha's Vineyard..once thought the ice was 20 feet thick when it covered the Island. But new discoveries under a 1742 hotel indicates it was at least 200 feet thick.
Can't watch because TH-cam's "fact-checking" box interferes with my view window. I honestly couldn't care less what TH-cam's corporate opinion is about any subject, but I can definitely say that when you try to force your ideas on me and tell me i'm not allowed to even hear a different opinion, or i'm not allowed to hear a different opinion without you "fact-checking" it for me, my first gut reaction is you are not only a liar but you are trying to harm me in some way not least of which by restricting or currating my access to information.
The issue of climate change is exactly like when whether of not the earth was the center of the universe, the "official" science behind it is exactly like the church during the debate about the center of the universe, it had it's "official" views and scientists and if you opposed them than you were persecuted, threatened and maybe even put to death if they could demonize you enough. Climate change is the new religion, just like a religion it's got it's official views and it's official scientists that can prove it, and if your views are different you're labeled as a heretic, fear and guilt, fear and guilt, just like any other religion oppose their views and you're labeled as someone who's "dooming your grandchildren to a living hell on earth". Fear and guilt, fear and guilt.
Me, too. I find both the Paleolithic and human evolution fascinating. North 02 and Highly Compelling are two great channels here at You Tube. I recommend both highly.
While enlightening, NOVA celebrates season 50 in 2023. The episode posted for us to enjoy is from Season 23 and first aired on Dec 31, 1996, Production code 2320(453). So as far as climate research goes, it's over 25 years out of date.
Isn't science amazing? People love when it gives us cell phones with GPS, but then they don't like it when it tells them that human activity is changing Earth's climate. Sorry folks, you got to take the good news with the bad news. Science doesn't prejudge.
Nova is one of my favorite and interesting programs to watch for any type of History of science . I thought of quite some time now what has to do with climate change and ice age occurrences.. I believe has a lot to do with the Earth change and access and wobble I've mentioned this before and what causes that several things and I'm surprised scientists don't look at this theory because in 2004 tsunami knocked the Earth's office access it was actually recorded.. seismographic activity and other variations of observation.... Be surprised with any other planet in the solar systems access is Disturbed or changed close to minute way all of the planets will drop in temperatures probably all kinds of other anomalies and events and activities take place...🤔 Maybe in my next lifetime lol
You said, “I’m surprised scientists don’t look at this theory…” What makes you think they haven’t? Do you honestly believe that YOU would’ve thought of this and the 1,000s upon 1,000s of scientists who actually study this stuff for a living and have done so for half a century - didn’t? In point of fact, they have. they’ve studied it thoroughly. What you’re referring to is the Milenkovitch Cycles, And they have been quite carefully studied and are currently not contributing any changes to the Earth’s climate. Wrong part of the cycle. Also, those cycles affect climate on a timescale of 100,000 years, NOT the 50-year timeframe in which the majority of climate change has occurred due to known manmade CO2 emissions. This is why they don’t usually mention them in most climate studies. It’s the same with the warming and cooling cycles of the Sun. Right now, the sun is in a cooling phase, so the Earth should be cooling down, not warming up. It’s all in the climate science literature, and you can find everything you need to know on the NASA climate website.
Not one of these guys mentioned trees. Growing up, the trees in my hometown were clear cut and the snowcapped mountains went bare, a few years ago I was back in my territory and the trees had grown back and so to were the snowcapped mountains.
What if the ice age was simply caused by an unfortunate confluence of events/effects? Asteroid impacts: Logancha, Siberia, 20 km wide, 40 mya Haughton, Nunavut, 23 km, 39 mya Mistastin, Labrador & Newfoundland, 28 km, 36.4 mya Chesapeake Bay, Virginia, 40 km, ~35 mya Popigai, Siberia, 100(!) km, ~36 mya That is some serious debris thrown into the atmosphere over the course of about 6 million years, especially from the last one: Popigai. Enough with changes in weather patterns and weathering to perhaps tip the balance? I wonder where this theory has gone in the last 30 years...
Very very little has melted. Today the rise in temperatures have slowed to a halt. The temperature has not risen in twenty years. We prepare now to round the top of the 1100 year heat spike and fall toward the next cooler cycle, accelerated by the coming Eddie Minimum. You have to understand the temperatures have been falling for near 4,000 years now. During this time there has been a brief heat spike every 1,100 years. The Minoan Warming, the Roman Warming, the Medieval Warming and now a thousand years later the Modern Warming all have come exactly when expected and developed exactly as expected. As the cooling period begins harvests are expected to fail. Wide Scale shortage of food has been projected on the planet before 2030.
@@cruisepaige Tried to respond. Filled with science, records from NASA, NOAH and UAH. References to various science groups... etc etc. Cannot post it. Doesnt fit your cult guidelines and undermines your delusions. They keep erasing the facts. So I suggest you take your contemptuously ignorant, out of contact, cult puppet butt to some real science sites and start investigating things. Less... readers digest version: Looks like your quoting HADCRUT5. Damned fraud. They make up data out of the blue, cherry pick data out of their source set and 'clean' the data base of data that doesn't comply to their goals and THEN they "homogenize" the resulting fraudulent data. HADCRUT5 gains 1/4 degree over the already fraudulent HADCRUT4, but that wasnt extreme enough for them. They had to be able to show its even warmer. How come we are now digging entire towns out of the permafrost in Greenland that were frozen a thousand years ago if its the very hottest ever ever ever? Hmmm? How come you are looking like an isolated and ignorant cult drama queen? Have you EVER actually investigated the climate. Doens't look to me like you have. Your spewing pure fantasia. No, its not the hottest ever. Hottest ever was in 1932 or 33. I forget which. Today isnt close. You want a decent look at todays temperatures? Go to UAH temperature and climate projects they have with NASA and NOAH and see what the temperature is before its manipulated by your cult propagandists. No matter what though, if you keep quoting your cult your going to end up looking like the fool you do look like. Get off your butt and investigate. Its clear you have never broached the subject, dont give a piss about climate and have no clue whats going on in reality. Deal with reality or its going to deal with you. You have till after 2025 to get your act together. Before 2030 global crop failure is forecast. you know why? Of course you dont. You only interested in being a cult puppet, not a bit interested in climate. Did you know that theory says that when an ice age comes the earth will have the hottest summers ever? No of course you didnt. Your not interested in either science or climate. Just in being a drama queen. Deal with reality or reality will deal with you. You have a few years left. Dont waste them on obeying your stupid cult.
4:00 "So much water got frozen solid that sea levels dropped 400ft" has nothing to do with solid or liquid but WHERE the water IS. Ice on LAND drops sea levels, not floating ice.
@@jeffreyhusack2400 When ice is floating in water it displaces *precisely* the same amount of water as if it were liquid. You can try it at home, take a bowl of water filled right to the top with ice *floating in the water,* but not stuck against sides or resting on the bottom. Notice some of the ice is higher than the edge of bowl, when ice melts no water will spill over edge of bowl. Whatever the level was it still will be. (((for many it's intuitively obvious but intuition comes from experience)))
I'm interested in prehistory. Tell us how the ice formation got to be kilometers deep. A deep drop in temperature does not automatically cause deep ice. The temperature must drop while the atmosphere in the area has water drifting through.
snows don't melt from year to year as in non ice ages..over hundreds of years the build up becomes significant..or you could just ask John Kerry..he's the irrefutable expert on this..
The only problem is that the Sahara desert has alternating between periods of drought and savannah. In fact the end of the last ice age was quite abrupt. I think the mountains do effect the climate for sure but the milankovitch cycles makes more sense as the cause of the ice age.
@jonathanturek5846 we are heading into a very deep minimum, and billions of people will starve. But it will take 20,000 years before our next scheduled global ice-age.
Maybe the entire Alpide Belt. It runs from out in the Atlantic and includes the Pyrenees, the Alps, the Carpathians, the Caucasus, Tien Shan, Pamir, Hindu Kush and Himalayas. They all rose at about the same time.
The older documentaries were so much better. Now a days it's made for people who have short attention span and need all kinds of stimuli incorporated into them. Not to mention they basically start over n repeat after each commercial break
Erosion worldwide picked-uup at 40 million with major changes in the patterns of sea floor spreading, i.e. the Pacific for one, and the rise of rocky terranes in North and South America and elsewhere. So, the strontium record needs to be examined worldwide if this has not been done. Personally, I come down on Dr. Maureen Raymon's theory as a major contributor. Thank youfor a most interesting NOVA episode, and to all of my fellow scientist--keep an open mind.
The mountains haven’t shrank so if it was these mountains what changed to make it warmer again and when did that warming take place . This could be addressed as I continue to watch .
I cannot understand how this has a caution note at the top. Outrageous. It's a theory of science. Whoop de do! If TH-cam was around back in Rutherford's time the irony is the new ideas he was coming up with would have been censored and ironically TH-cam wouldn't have a medium as a result. Get a grip you tube for the love of God
Mountains definitely drive the weather, but the himalayas accounts for a small fraction of the entire Earth's land surface, could this relatively small area cause global ice age?
Who says that it's not. And remember every strip mine is exposing new land to chemical erosion. All that strip mining they're doing in Canada and the Midwest. A modern version of the Himalayas LOL
Good question, and I take it as a sincere question, not rhetorical. The hypothesis discussed in this video is that over the course of millions of years of geologic uplift and chemical erosion, the Himalayas removed enough CO2 from the atmosphere to initiate a period of glaciation. Earth systems exist in states of equilibrium or quasi equilibrium. When we do things to upset the balance, there are consequences. Over the course of geologic time, which spans billions of years, it has been documented that variation in atmospheric carbon dioxide has provided the "biggest control knob" on Earth's surface temperatures. Look up talks by Professor Richard Alley from Penn State if you'd like to learn more about this. There's no reason why CO2 would suddenly stop being the biggest control knob, just because it makes people feel upset for political reasons. It's _still_ the biggest control knob.
@@willfriar8054 it's good to think creatively, but sometimes our intuitions lead us in the wrong direction. That's why we have science to provide better answers. The types of rocks that are exposed in most strip mines do not have the right chemical composition to remove carbon dioxide from the atmosphere. Actually, if they are coal strip mines, they will release carbon dioxide into the atmosphere, not only by combustion of the coal that's removed, but by chemical weathering of the carbon- rich material that's left behind. Sorry, but that's not going to help us.
@@SurvivorsStories They should have. A lot of off-road vehicles have compressors just for that reason. Lower the tyre pressure in sand, then pump it back up for rock. It gives you more of a footprint, so the load is distributed over more area.
"Climate change refers to long-term shifts in temperatures and weather patterns, mainly caused by human activities, especially the burning of fossil fuels." - - Actually humans contribute a relatively small percentage of greenhouse gasses to the over all total emitted - but, it just happens to be the percentage that tips the balance - and accounts for most of the accumulating build up in the atmosphere.
Your view is wrong. Read the science literature, visit the NASA Climate website, take a university course (like I did) in climate science, whatever. Opinions mean nothing when unsupported by the evidence.
Wow, this is REALLY OLD. I looked it up and this episode first aired in 1997, that's 25 years ago, and there are so many more details and better theories to explain what happened in Earth's ancient past. The Milankovitch cycles are now a standard explanation for the ice ages occurring every 100,000 years, evidence for one or more "Snowball Earths" dating back to the beginnings of life on Earth has also accumulated. In 1997, people were still more worried about a global nuclear winter from the fallout of a massive thermonuclear world war than about global warming from greenhouse gases. Science marches on......
As soon as it started I was thinking….this must be old. Even the narrator’s voice seems 90s. 😳 I’ll have to look up a more updated video on the subject.
Odd, Al Gore was vice president at the time and you're saying that climatic change was not a concern at the time... fascinating. There are cartoon shows from the 1980s that had PSAs at the end, and climatic change... I mean Global Warming, was a topic of concern. You've obviously never seen Captain Planet have you.
@@puppiesarepower3682 I knew about climate change way back in 8th grade, in 1970, when I read in our science textbook that 1) carbon dioxide in the atmosphere increases the greenhouse effect, and 2) carbon dioxide in the atmosphere was steadily increasing because of fossil fuels. Now, these bits of fact were presented on separate pages in the textbook, and there was no connection made between the two, but it wasn't hard to see the link and so in class, I asked the science teacher, "doesn't that mean the climate is going to get warmer and warmer on Earth?" And the science teacher thought for a minute and said, "yeah, you're right, it probably will, but that won't be for another hundred years, and then we'll all be dead!" Well, that was over fifty years ago, so, he was pretty close - in another fifty years the full force of global warming will be upon us. As to Captain Planet, no never heard of it, never watched it. If you were old enough to be paying attention to the news in the 1980s instead of watching cartoon shows, the news was full of Reagan's military buildup, the neutron bomb, the basing of nuclear capable Pershing missiles in Germany, and the massive protests against all that in favor of "world peace". In the midst of all that, Carl Sagan's group came out with the hugely influential "Nuclear Winter" paper in 1983, postulating that the dust from a global nuclear war would cause a massive global freeze. This pretty much drowned out whatever faint messages of global warming were out there at the time. In the 1990s, whatever Gore was doing as vice-president during the Clinton administration was swamped by the news media circus going on with the Clintons during that time. He didn't really make an impact until he came out with his movie documentary "An Inconvenient Truth" in 2006. That movie served as the clarion call that finally brought global warming to the forefront of public attention. By then, the Soviet Union had broken up, Shrub had declared Vladmir Putin to be "trustworthy", and the possibillty of a nuclear winter seemed remote. Today, despite Russia and North Korea constantly threatening to use nuclear weapons, people (other than the diehard preppers) still seem very blase about this possibility of a nuclear winter. A nuclear winter would actually be a pretty solid cure for the ongoing global warming.
@@gandalfgreyhame3425 man you like yourself... a bit long winded mate. So we all agree its Co2.. Since we have been in a ice age for 2.6 million years currently and glacial periods only seem to come from major confluences of many factors. That last statement about a nuclear winter would actually create global warming more since plants actually hold more Co2 and reflective clouds/ air particulates would reduce the suns radiation if a nuclear winter lasted for more than a year effectively killing them the Co2 in the atmosphere would certainly jump significantly.
Soooo... If I get it, we need to burn coal, oil, natural gas, and wood to compensate the impact of the Himalaya on climate? COOL! Question: Will Homo live long enough to win the fight against the mountains? And what happens when MORE mountains build up, such as during the closure of the Mediterranean Sea or the Bearing Strait? Two million years is a LOONG time AND species evolve a lot faster than what Darwin thought, ESPECIALLY when there are major environmental changes.
There is no way we can intelligently say the last Ice Age was the worst, especially since there is also speculation about Snowball Earth, a time when the entire globe was frozen.
Good question! Strontium can substitute for calcium in the +2 valence state in the crystal structure of aragonite, one of the two main forms of calcium carbonate. Aragonite is the main form of calcium carbonate used by marine organisms, because it is structurally stronger than calcite, which is the other major form. As aragonite transforms into calcite over long periods of time, which it will do, the strontium is expelled from the crystal structure and released into the surrounding rocks.
Great insight to combat the current climate change hysteria. The hystericals will not listen, they wallow in ignorance and self flagelation. Fine, don't inflict it on us! Thank you
What if the Hysteria is actually coming from science denialists who are frantically and hysterically waving their arms, jumping up and down, and screaming that the science is a hoax? Actual climate scientists are extremely careful in the conclusions that they draw, and characterizing them as "hysteria" is irresponsible. I'm guessing the scientific content of this video went over your head. It provides further evidence supporting the broadly held scientific understanding of present-day climate change. It will take thousands of years at minimum for geologic processes to remove the carbon dioxide we are presently dumping in the atmosphere. In the meantime, that CO2 will continue to cause warming, because that's what greenhouse gases do. That's why climate scientists are so concerned. Their science-based concerns do not seem hysterical to me.
If the rise of the Himalayas caused an ice age, then why are we not still in one? Are they not still rising and eroding? I'm disappointed that I didn't hear this very obvious question be addressed.
That’s because the Milankovitch cycles are NOT currently having an effect on Earth’s climate, so why mention it? Moreover, those cycles affect earths climate on 100,000 year cycle, not the last 50 years in which the majority of our climate change has occurred from manmade CO2 emissions. And yes, they do know that the excess CO2 accumulations are from fossil fuels because they carry the C12 isotope signature, which can only come from fossil fuels.
@@ronaldjanert7456 my comment wasn't disputing modern day climate change as I am not a climate denier. The damage brought on by fossil fuels is indisputable. The video of cracking the ice age centered around the building of the Himalyas as the primary driver of the last ice age. Nowhere in the documentary did they mention the Malencavic Cycles. I found that fascinating.
Considering humans have only been burning fossil fuels in any appreciable quantity in the last 200 years how can you say what is actually causing the rise and fall of interglacials and glacial. There have been 33 reversals from one to the other in the last 2.6 million years based on oxygen isotopes so perhaps you ought to just keep trying to learn instead of just buying all the b******* that somehow text dollars are going to be able to fix this
@@douglashanlon1975 It’s not a matter of how long humans have been around burning fossil fuels. What’s at issue is HOW MUCH of it we’ve been burning, and HOW FAST. Before us, Earth’s Carbon cycle has been in BALANCE (i.e., equal amounts drawn out of the atmosphere vs. How much gets released naturally). that has kept our climate extremely stable for the last 8,000 years, and relatively stable for the last 800,000 years. The problem is, the Earth can only absorb a certain amount at a certain speed, and CO2 persists in the atmosphere from a 100 to a 1,000 years before it’s circulated back out again. That means that everything extra we emit ACCUMULATES year over year, the same way a bathtub fills up over time and eventually overflows under a dripping faucet when it’s not allowed to drain as fast as it’s accumulating. And that faucet’s been dripping faster and faster over the last 200 years. The greatest amount of accumulation of CO2 has occurred in only the last 40-50 years thanks to Globalization. That’s why it’s risen from 280 ppm to 419 ppm in so short a time. As for your argument about glacial and interglacial periods, they’re irrelevant to any discussions about our CURRENT climate situation. Why? Because those happen in roughly 100,000 year cycles in response to variations in the Earth’s orbit and axial tilt (Milankovich Cycles) and there are currently no appreciable changes that can even remotely, possibly have an effect on our current climate, and they most certainly can’t explain the speed at which the Earth is heating up. None. There is no natural explanation for the speed at which global warming is occurring. The science doesn’t match what we’re witnessing. Moreover, the isotopic signature of the carbon building up in the atmosphere proves the excess CO2 is human-caused because the ratio of C12 is increasing relative to C13, and that can only come from fossil fuels where it’s been shielded for millions of years from the ionizing effects of solar radiation.
@@davidkelter8379 Be careful about demonizing fossil fuels, you are condemning your own existence, few of us would be around without them. It's time to faze them out but they have done vastly more good than bad, saved the whales, we would've wiped out pretty much all the worlds forests for fuel, and the actual *science* (as apposed to popular propaganda) strongly suggests 280ppm CO2 is way lower than ideal.
Never forget about boils law because this explains what happens on mountains they can't start a ice age, its only the orbit of the moon and sun creates ice age
Africa and South America separated much earlier (during the Mesozoic), before there Was a Gulf Stream. But the much more recent creation of the Isthmus of Panama (by volcanism) separated Atlantic from Pacific ocean currents and could have affected the Gulf Stream, and the amount of moisture available to form glaciers in Europe.
I would have thought the mountains would block the cold air from dispersing to the south, thus concentrating it in the northern climes and causing more ice formation from less snow melting. There's snow on top of the mountains because it's colder up there, not warmer. More snow would mean more reflecting of sunlight whereas bare rock would heat more but to what degree if it's pretty cold rock to begin with? Has anyone ever found warm rocks up there, or are they all cold?
They're all cold at that altitude. If they were climbing an active volcano, there would be a pretty good chance of finding warm rocks at high altitude 😂😉
40k in round numbers. That's colloquial for latest (probably not last) glacial maximum, strictly speaking we *are in the ice ages* beginning aprox. 3M yrs ago to present, with relatively brief interglacial times like now, alternated with longer glacial periods. We are roughly 'due' for next glacial max, 'soon' to a couple thousand yrs out. We are on the cusp of tech/economic power to prevent next devastating event but CO2 probaly will not do the job, even a lot more than now in the atmosphere, it will at least marginally reduce the risk of mass plant extinction caused by dangerously low CO2 levels (meaning the end of everything that matters) that recent glacial max events have just skirted.
We should stop dumping so much CO2 in the atmosphere. That is within our power, albeit very difficult. Raising or lowering the Himalayas is obviously not within our power, but I guess you knew that HA-HA. It may be that there's nothing we can do to stop global warming, but that doesn't mean we shouldn't try.
So, Ice melts revealing more rock. Rock cools the earth into making more ice? Or the melting causes flooding and that facilitates moving of the tectonic plates, pushing up more rock and cooling the earth? Smh I'm just a plumber, but whatever is going on it's cyclical it seems.
The sun decides many things, not everything. If it were up to the Sun, the Earth would have been cooling over the past four decades that we have had reliable measurements of solar emissivity. The present day warming is being caused by increased concentrations of greenhouse gases. Sometimes the world is more complicated than we would like, but that's why we have science, rather than just intuition, to answer questions. Intuition alone is insufficient to answer scientific questions.
@@susancaleca4796 I quickly looked up "glacial periods in Earth's history" on Google, and came up with the following: "Scientists have recorded five significant ice ages throughout the Earth's history: the Huronian (2.4-2.1 billion years ago), Cryogenian (850-635 million years ago), Andean-Saharan (460-430 mya), Karoo (360-260 mya) and Quaternary (2.6 mya-present)." The Mesozoic, which spanned the "age of dinosaurs", from about 252 to 66 million years ago, is NOT included.
The planet has been cooling for near 4,000 years now and during this time there has been a brief heat spike every 1100 years. Like the Minoan Warming, the Roman Warming after it, the Medieval Warming after it, the Modern Warming today came exactly when expected and developed exactly how expected. Today we round the top and begin the slide down the falling side of the spike to a new and even colder period than before, known as the Little Ice Age. As this happens the Eddy Minimum is due, likely in the early 2030's. As we chill once again harvests are expected to fail. Global crop failure is forecast before 2030. If you were to measure the ice on the planet you would find that there has been more ice in the last few hundred years than in the last ten thousand all added up together. Never in the entire Holocene as this pattern of climate developed. The only time this sort of pattern has ever emerged is when the previous Interglacial Periods came to a close. It indeed does look like the Holocene is ending and today is warmest it will be for the next 100,000 years. Start a garden.
Many people confuse "glacial period" with "ice age". An Ice Age is a long-term period (up to millions of years) during which multiple glacial and interglacial periods can occur. The program was about the long-term cause of the current Ice Age. They also touched on how glacial/interglacial periods match cyclical changes in the earth's orbit (and axial tilt and precession). Ocean sediment cores indicate that around 8 to 10 glacial/interglacial cycles have happened over the last 800,000 years. But on land, the most recent continental glaciation tended to "bulldoze" away the record of the previous ones (but not everywhere). The most recent cycle lasted about 100,000 years, and glaciation peaked around 26,000 years ago.
If there was rain, rivers and green in North Africa, as we know that there was, and if that scenario presupposes the absence of the current high Himalayan plateau and current high mountains, then if your model is true, absent counting other factors, then the Himalayan situation might be only several thousand years old? The Himalayan mountains are SHARP and the glaciers are NEW, as I look at them. The peaks and even sides and approaches are unworn. The effects of the glaciers are almost negligible. Another subject, but I have examined the Grand Canyon. It just happened recently. The side canyons are brand new. It cannot be explained by gradual wear. The streams in the side canyons, have polished their beds a small amount, but cannot account AT ALL for the presence of those canyons. The streams do not even connect to the plateau. If the Colorado were ten times its current flow it would not begin to explain what I saw in the main canyon. The wear by the river explains NOTHING. The present scenario of lateral erosion by the river is a JOKE. Geological science needs a turn off and re-boot. Start over, but this time with INTELLIGENT PEOPLE, able to scientifically assess what we actually see, not what novelists want to imagine
@@ronaldjanert7456 Who is talking about at this time? We are going back millions of years and this would certainly include Milankovitch cycles. That being said, I think it was more than just the Himalayas that caused the ice ages. We are still in one (tail end) actually, but global warming will take care of that.
![“อ.เบียร์ คนตื่นธรรม” มาตามคำเรียกร้อง แหกศาสตร์ฮวงจุ้ย เตือนสติอย่างมงาย | แฉ 7 พ.ย. 67 [1/3]](http://i.ytimg.com/vi/5fc4S3xBNfc/mqdefault.jpg)
More activity for any video from you = more documentaries from me. Enjoy
I get just as excited watching the Nova intro as I do a 20th Century Studios or Universal or Columbia logo. I just know it's going to teach me something I never knew, and new knowledge is just another piece of the infinite puzzle.
Koch Industries is a big supporter of Nova
Nova is funded b ye christian extremist's.
@@DSAK55 As they go about destroying the earth 🐖 🐷
I usually do too but this wasn't the one I'm used too though...
True indeed
For many documentary lovers, NOVA was their first love.
😇
INDEED
I cut my TV documentary teeth on NOVA! I've been hooked since the first episode in '74, and love all the documentary content PBS gives us!! Thank you so much for NOVA full episode docs and may I request BBC's "How to Grow A Planet" narrated my Dr. Iain Stewart please? ❤😀🙏
For sure!
I just love these old documentaries…. The sponsors the voice …the filming just sooooo 90’s 😫
Missing pull tabs on them PBR's......more like 70's. I grew up in the 80's and as a kid I remember the big deal it was when they switched from pull tabs on cans to the pop tops where the tab stayed attached to the tops. That was a huge deal when it came out...in the 80's so this doc is dated in the 1970's.
@@murdockdacoon2055 really …. Wow 😯 it looks too good for 70’s but point taken 👍🏽
It was genuine entertainment and educational then …. Now so much drivel out there!
Bring back VHS 😊
@murdockdacoon2055 I remember that! lololol
It's amazing to watch these older documentaries. The detail of the understanding of the past was reasonable accurate but crude. The amount of studies and detail that have been added since this documentary was produced is astounding.
It's both wonderful and utterly terrifying.
I loved the video and the tell on age of the show with the Pabst Blue Ribbon in a tin can instead of aluminum.
I was just thinking the same thing. It was made before geologists learned of snowball earth or any of the early mass glaciations. And the description of the Earth forming in an inferno of molten rock and gas with an image of Hawaiian lava bujbbling away gives the gist, but of course we now know a good deal more from the Theia collision to Jupiter wandering in and wandering out again.
Yah... its been proven an outright fraud.
@@sacredweeds for me the time click was the computer graphics
Anything Nova does is worth watching ☺️
I have to get up and do my paid job now but all I want to do is learn more about this. Even reading the comments is educational!
As well so are you
I freakin love NOVA. I’ve learned so much over the years from their programming. Thanks. Subbed 👍🏼
From Martha's Vineyard..once thought the ice was 20 feet thick when it covered the Island. But new discoveries under a 1742 hotel indicates it was at least 200 feet thick.
Can't watch because TH-cam's "fact-checking" box interferes with my view window. I honestly couldn't care less what TH-cam's corporate opinion is about any subject, but I can definitely say that when you try to force your ideas on me and tell me i'm not allowed to even hear a different opinion, or i'm not allowed to hear a different opinion without you "fact-checking" it for me, my first gut reaction is you are not only a liar but you are trying to harm me in some way not least of which by restricting or currating my access to information.
It's called censorship .
The issue of climate change is exactly like when whether of not the earth was the center of the universe, the "official" science behind it is exactly like the church during the debate about the center of the universe, it had it's "official" views and scientists and if you opposed them than you were persecuted, threatened and maybe even put to death if they could demonize you enough.
Climate change is the new religion, just like a religion it's got it's official views and it's official scientists that can prove it, and if your views are different you're labeled as a heretic, fear and guilt, fear and guilt, just like any other religion oppose their views and you're labeled as someone who's "dooming your grandchildren to a living hell on earth".
Fear and guilt, fear and guilt.
@@y4s563lol , only in America
Hear Hear !
Snap
I am a fan of Paleolithic period and human evolution, this documentary was good and useful
Me, too. I find both the Paleolithic and human evolution fascinating. North 02 and Highly Compelling are two great channels here at You Tube. I recommend both highly.
Thank you for this video
Great program , very interesting facts and great hypothesis
While enlightening, NOVA celebrates season 50 in 2023. The episode posted for us to enjoy is from Season 23 and first aired on Dec 31, 1996, Production code 2320(453). So as far as climate research goes, it's over 25 years out of date.
So its 75 years more up to date than the data used by Shell, Texaco, and Exxon
At least the title doesn't contain the ridiculous TH-cam dog-whistle word "insane."
@@danbeaulieu2130😂😂😂
@@JMDinOKCor "ridiculous" 😂😂😂
Or "facts that have scientists terrified"
This is pretty old, but still good....the phone I'm typing this on can tell me my elevation and coordinates, to five places...
Isn't science amazing? People love when it gives us cell phones with GPS, but then they don't like it when it tells them that human activity is changing Earth's climate. Sorry folks, you got to take the good news with the bad news. Science doesn't prejudge.
Nova is one of my favorite and interesting programs to watch for any type of History of science . I thought of quite some time now what has to do with climate change and ice age occurrences.. I believe has a lot to do with the Earth change and access and wobble I've mentioned this before and what causes that several things and I'm surprised scientists don't look at this theory because in 2004 tsunami knocked the Earth's office access it was actually recorded.. seismographic activity and other variations of observation.... Be surprised with any other planet in the solar systems access is Disturbed or changed close to minute way all of the planets will drop in temperatures probably all kinds of other anomalies and events and activities take place...🤔 Maybe in my next lifetime lol
You said, “I’m surprised scientists don’t look at this theory…” What makes you think they haven’t? Do you honestly believe that YOU would’ve thought of this and the 1,000s upon 1,000s of scientists who actually study this stuff for a living and have done so for half a century - didn’t?
In point of fact, they have. they’ve studied it thoroughly. What you’re referring to is the Milenkovitch Cycles, And they have been quite carefully studied and are currently not contributing any changes to the Earth’s climate. Wrong part of the cycle. Also, those cycles affect climate on a timescale of 100,000 years, NOT the 50-year timeframe in which the majority of climate change has occurred due to known manmade CO2 emissions. This is why they don’t usually mention them in most climate studies.
It’s the same with the warming and cooling cycles of the Sun. Right now, the sun is in a cooling phase, so the Earth should be cooling down, not warming up. It’s all in the climate science literature, and you can find everything you need to know on the NASA climate website.
It's far more profitable to talk about "climate change"... Actual reality be damned.
Not one of these guys mentioned trees. Growing up, the trees in my hometown were clear cut and the snowcapped mountains went bare, a few years ago I was back in my territory and the trees had grown back and so to were the snowcapped mountains.
What if the ice age was simply caused by an unfortunate confluence of events/effects?
Asteroid impacts:
Logancha, Siberia, 20 km wide, 40 mya
Haughton, Nunavut, 23 km, 39 mya
Mistastin, Labrador & Newfoundland, 28 km, 36.4 mya
Chesapeake Bay, Virginia, 40 km, ~35 mya
Popigai, Siberia, 100(!) km, ~36 mya
That is some serious debris thrown into the atmosphere over the course of about 6 million years, especially from the last one: Popigai. Enough with changes in weather patterns and weathering to perhaps tip the balance? I wonder where this theory has gone in the last 30 years...
Since this episode aired in 1996, I wonder how much of the ice depicted still exists?
Very very little has melted. Today the rise in temperatures have slowed to a halt. The temperature has not risen in twenty years. We prepare now to round the top of the 1100 year heat spike and fall toward the next cooler cycle, accelerated by the coming Eddie Minimum.
You have to understand the temperatures have been falling for near 4,000 years now. During this time there has been a brief heat spike every 1,100 years. The Minoan Warming, the Roman Warming, the Medieval Warming and now a thousand years later the Modern Warming all have come exactly when expected and developed exactly as expected. As the cooling period begins harvests are expected to fail. Wide Scale shortage of food has been projected on the planet before 2030.
@@scinanisern9845few people these days discuss these facts, thank you for bringing them to light here ❤
@@scinanisern9845you seriously wrote this during the #1 hottest and #2 hottest months on earth EVER recorded???!
@@cruisepaige
Tried to respond. Filled with science, records from NASA, NOAH and UAH. References to various science groups... etc etc. Cannot post it. Doesnt fit your cult guidelines and undermines your delusions. They keep erasing the facts.
So I suggest you take your contemptuously ignorant, out of contact, cult puppet butt to some real science sites and start investigating things.
Less... readers digest version:
Looks like your quoting HADCRUT5. Damned fraud. They make up data out of the blue, cherry pick data out of their source set and 'clean' the data base of data that doesn't comply to their goals and THEN they "homogenize" the resulting fraudulent data. HADCRUT5 gains 1/4 degree over the already fraudulent HADCRUT4, but that wasnt extreme enough for them. They had to be able to show its even warmer.
How come we are now digging entire towns out of the permafrost in Greenland that were frozen a thousand years ago if its the very hottest ever ever ever? Hmmm? How come you are looking like an isolated and ignorant cult drama queen? Have you EVER actually investigated the climate. Doens't look to me like you have. Your spewing pure fantasia. No, its not the hottest ever. Hottest ever was in 1932 or 33. I forget which. Today isnt close. You want a decent look at todays temperatures? Go to UAH temperature and climate projects they have with NASA and NOAH and see what the temperature is before its manipulated by your cult propagandists. No matter what though, if you keep quoting your cult your going to end up looking like the fool you do look like.
Get off your butt and investigate. Its clear you have never broached the subject, dont give a piss about climate and have no clue whats going on in reality. Deal with reality or its going to deal with you. You have till after 2025 to get your act together. Before 2030 global crop failure is forecast. you know why? Of course you dont. You only interested in being a cult puppet, not a bit interested in climate. Did you know that theory says that when an ice age comes the earth will have the hottest summers ever? No of course you didnt. Your not interested in either science or climate. Just in being a drama queen. Deal with reality or reality will deal with you. You have a few years left. Dont waste them on obeying your stupid cult.
@@cruisepaige. 👍Mind blowing... let's hope these people don't reproduce.
Great one, thank you👍🏼🌸
You're welcome ^^)
4:00 "So much water got frozen solid that sea levels dropped 400ft" has nothing to do with solid or liquid but WHERE the water IS. Ice on LAND drops sea levels, not floating ice.
Not sure if I believe the solid liquid topic
@@jeffreyhusack2400 ??
@@Mrbfgray don't matter where the water is when it freezes it will lower water levels because it's been replaced by a solid.
@@jeffreyhusack2400 When ice is floating in water it displaces *precisely* the same amount of water as if it were liquid. You can try it at home, take a bowl of water filled right to the top with ice *floating in the water,* but not stuck against sides or resting on the bottom.
Notice some of the ice is higher than the edge of bowl, when ice melts no water will spill over edge of bowl. Whatever the level was it still will be.
(((for many it's intuitively obvious but intuition comes from experience)))
I'm interested in prehistory. Tell us how the ice formation got to be kilometers deep. A deep drop in temperature does not automatically cause deep ice. The temperature must drop while the atmosphere in the area has water drifting through.
snows don't melt from year to year as in non ice ages..over hundreds of years the build up becomes significant..or you could just ask John Kerry..he's the irrefutable expert on this..
Continental ice sheets aren't created overnight. It takes years, maybe even thousands of years to accumulate. Neither do they disperse overnight.
Great documentary! Hope more sense video to come THANKS NOVA
The only problem is that the Sahara desert has alternating between periods of drought and savannah. In fact the end of the last ice age was quite abrupt. I think the mountains do effect the climate for sure but the milankovitch cycles makes more sense as the cause of the ice age.
That and both whether there is ice at the poles and the current position of the continents in the Northern Hemisphere surrounding the North Pole.
So do comets that hit Earth, as in the Younger Dryas period.
Yes, the global temperature change that we are experiencing now is one of the slowest in the earth's history!
Could it be a combination of said hypothesis a perfect storm of situations that contributed ? I say yes
@jonathanturek5846 we are heading into a very deep minimum, and billions of people will starve. But it will take 20,000 years before our next scheduled global ice-age.
You forgot to mention & explain the "Milankovic Cycles" and their influence on the climate
Very interesting analogy software. 👍🌬️
I don't think it was Himalayas alone . Although I think they contributed to the Ice Ages .
Maybe the entire Alpide Belt. It runs from out in the Atlantic and includes the Pyrenees, the Alps, the Carpathians, the Caucasus, Tien Shan, Pamir, Hindu Kush and Himalayas. They all rose at about the same time.
How old is this documentary?
The 4 : 3 frame makes me think it's older than the Himalayas
its from the early 2000's. 2003 I believe.
If you’re genuinely curious, try finding that information in the most obvious place: look at the •credits•. At 55:12, we see, “© 1996”.
The real mystery is, why does anyone need help figuring this out?
@@ColumbiaB Nature and nurture are often irresponsible. Why we invented science.
@ColumbiaB +1 million credits for you for information for inattentive people. Thank you! Gosh...face palm
The older documentaries were so much better. Now a days it's made for people who have short attention span and need all kinds of stimuli incorporated into them. Not to mention they basically start over n repeat after each commercial break
Erosion worldwide picked-uup at 40 million with major changes in the patterns of sea floor spreading, i.e. the Pacific for one, and the rise of rocky terranes in North and South America and elsewhere. So, the strontium record needs to be examined worldwide if this has not been done. Personally, I come down on Dr. Maureen Raymon's theory as a major contributor. Thank youfor a most interesting NOVA episode, and to all of my fellow scientist--keep an open mind.
Things have been updated a lot since 1994 - OMG that's 29 years ago!! Holy cow time flies! 🤯
The mountains haven’t shrank so if it was these mountains what changed to make it warmer again and when did that warming take place .
This could be addressed as I continue to watch .
Thanks!❤
I cannot understand how this has a caution note at the top. Outrageous. It's a theory of science. Whoop de do!
If TH-cam was around back in Rutherford's time the irony is the new ideas he was coming up with would have been censored and ironically TH-cam wouldn't have a medium as a result.
Get a grip you tube for the love of God
Roger
Old are gold, voice ❤
Mountains definitely drive the weather, but the himalayas accounts for a small fraction of the entire Earth's land surface, could this relatively small area cause global ice age?
Who was it who said, "I'm too intelligent to believe in climate change" ?
Wow Thanks, my friend 👍👏👏👏
Why isn't the Himalayas contributing to cooling temperatures now?
The rhetorical question...
Who says that it's not. And remember every strip mine is exposing new land to chemical erosion. All that strip mining they're doing in Canada and the Midwest. A modern version of the Himalayas LOL
Good question, and I take it as a sincere question, not rhetorical.
The hypothesis discussed in this video is that over the course of millions of years of geologic uplift and chemical erosion, the Himalayas removed enough CO2 from the atmosphere to initiate a period of glaciation. Earth systems exist in states of equilibrium or quasi equilibrium. When we do things to upset the balance, there are consequences.
Over the course of geologic time, which spans billions of years, it has been documented that variation in atmospheric carbon dioxide has provided the "biggest control knob" on Earth's surface temperatures. Look up talks by Professor Richard Alley from Penn State if you'd like to learn more about this.
There's no reason why CO2 would suddenly stop being the biggest control knob, just because it makes people feel upset for political reasons. It's _still_ the biggest control knob.
@@willfriar8054 it's good to think creatively, but sometimes our intuitions lead us in the wrong direction. That's why we have science to provide better answers.
The types of rocks that are exposed in most strip mines do not have the right chemical composition to remove carbon dioxide from the atmosphere. Actually, if they are coal strip mines, they will release carbon dioxide into the atmosphere, not only by combustion of the coal that's removed, but by chemical weathering of the carbon- rich material that's left behind. Sorry, but that's not going to help us.
"12,000 years ago the ice sheet shrank away" That's when man started driving SUVs and TH-cam says it was from burning fossil fuels.
12000 years ago our suv's were much larger and used 10 times the fossil fuel we use today.back then fuel was almost $5 /gallon.
Do unto others as you would have done unto you is a forever law.
What did you do, check this out from the library and upload it?
How would one put on paper the climactic hypotheses that involve the interaction of CO2 and weathering?
The rhetorical question...
47:19 Lower the tyre pressure. Off-road driving 101 when you're in sand.
Realy interesting: did they know that at that days?
@@SurvivorsStories They should have. A lot of off-road vehicles have compressors just for that reason. Lower the tyre pressure in sand, then pump it back up for rock. It gives you more of a footprint, so the load is distributed over more area.
50 years later , news flash it is still melting. Oceans are rising. We are getting a lot more meteorites are way.
I figured it's always Near Earth Object that makes it what ever it get cold or hot.
"Climate change refers to long-term shifts in temperatures and weather patterns, mainly caused by human activities, especially the burning of fossil fuels." - - Actually humans contribute a relatively small percentage of greenhouse gasses to the over all total emitted - but, it just happens to be the percentage that tips the balance - and accounts for most of the accumulating build up in the atmosphere.
It was a combination of things. From the Earth's orbet to volcanoes to ocean 🌊 currents. In my view.
Your view is wrong. Read the science literature, visit the NASA Climate website, take a university course (like I did) in climate science, whatever. Opinions mean nothing when unsupported by the evidence.
Sure, but not relevant to my comment but maybe it was too obvious to note.
Your view? “Orbet?”
Wow, this is REALLY OLD. I looked it up and this episode first aired in 1997, that's 25 years ago, and there are so many more details and better theories to explain what happened in Earth's ancient past. The Milankovitch cycles are now a standard explanation for the ice ages occurring every 100,000 years, evidence for one or more "Snowball Earths" dating back to the beginnings of life on Earth has also accumulated. In 1997, people were still more worried about a global nuclear winter from the fallout of a massive thermonuclear world war than about global warming from greenhouse gases. Science marches on......
As soon as it started I was thinking….this must be old. Even the narrator’s voice seems 90s. 😳 I’ll have to look up a more updated video on the subject.
Odd, Al Gore was vice president at the time and you're saying that climatic change was not a concern at the time... fascinating.
There are cartoon shows from the 1980s that had PSAs at the end, and climatic change... I mean Global Warming, was a topic of concern.
You've obviously never seen Captain Planet have you.
@@puppiesarepower3682 I knew about climate change way back in 8th grade, in 1970, when I read in our science textbook that 1) carbon dioxide in the atmosphere increases the greenhouse effect, and 2) carbon dioxide in the atmosphere was steadily increasing because of fossil fuels.
Now, these bits of fact were presented on separate pages in the textbook, and there was no connection made between the two, but it wasn't hard to see the link and so in class, I asked the science teacher, "doesn't that mean the climate is going to get warmer and warmer on Earth?"
And the science teacher thought for a minute and said, "yeah, you're right, it probably will, but that won't be for another hundred years, and then we'll all be dead!"
Well, that was over fifty years ago, so, he was pretty close - in another fifty years the full force of global warming will be upon us.
As to Captain Planet, no never heard of it, never watched it.
If you were old enough to be paying attention to the news in the 1980s instead of watching cartoon shows, the news was full of Reagan's military buildup, the neutron bomb, the basing of nuclear capable Pershing missiles in Germany, and the massive protests against all that in favor of "world peace".
In the midst of all that, Carl Sagan's group came out with the hugely influential "Nuclear Winter" paper in 1983, postulating that the dust from a global nuclear war would cause a massive global freeze. This pretty much drowned out whatever faint messages of global warming were out there at the time.
In the 1990s, whatever Gore was doing as vice-president during the Clinton administration was swamped by the news media circus going on with the Clintons during that time. He didn't really make an impact until he came out with his movie documentary "An Inconvenient Truth" in 2006. That movie served as the clarion call that finally brought global warming to the forefront of public attention. By then, the Soviet Union had broken up, Shrub had declared Vladmir Putin to be "trustworthy", and the possibillty of a nuclear winter seemed remote.
Today, despite Russia and North Korea constantly threatening to use nuclear weapons, people (other than the diehard preppers) still seem very blase about this possibility of a nuclear winter. A nuclear winter would actually be a pretty solid cure for the ongoing global warming.
@@gandalfgreyhame3425 man you like yourself... a bit long winded mate.
So we all agree its Co2.. Since we have been in a ice age for 2.6 million years currently and glacial periods only seem to come from major confluences of many factors.
That last statement about a nuclear winter would actually create global warming more since plants actually hold more Co2 and reflective clouds/ air particulates would reduce the suns radiation if a nuclear winter lasted for more than a year effectively killing them the Co2 in the atmosphere would certainly jump significantly.
Note that in the credits, at 55:12, we see, “© 1996”.
That could probably be consistent with a first air date, at some outlets, in 1997.
A synthesis is just another way to say I'm guessing, kind of a theory, what do you believe.
What about ocean currents and the oceans conveyor belt?
That makes way more sense to me then some complex Guessing game
That's what I'm talking about...
Soooo... If I get it, we need to burn coal, oil, natural gas, and wood to compensate the impact of the Himalaya on climate? COOL! Question: Will Homo live long enough to win the fight against the mountains? And what happens when MORE mountains build up, such as during the closure of the Mediterranean Sea or the Bearing Strait? Two million years is a LOONG time AND species evolve a lot faster than what Darwin thought, ESPECIALLY when there are major environmental changes.
There is no way we can intelligently say the last Ice Age was the worst, especially since there is also speculation about Snowball Earth, a time when the entire globe was frozen.
Yeah, that's right! I know this hypothesis. Did some presentation about this when I was student
See also the Hamaker theory. The older movie "Stopping the Coming Ice Age" is out there, as an older idea.
Thanks for advise!
How does calcium carbonate have strontium?
Good question! Strontium can substitute for calcium in the +2 valence state in the crystal structure of aragonite, one of the two main forms of calcium carbonate. Aragonite is the main form of calcium carbonate used by marine organisms, because it is structurally stronger than calcite, which is the other major form. As aragonite transforms into calcite over long periods of time, which it will do, the strontium is expelled from the crystal structure and released into the surrounding rocks.
These guys probably couldn't get funding today. Not enough talk about the nasty humans.
the kite at the 1:12 mark did not fly off because of the wind.
Has anyone at MIT given a thought that was anything was there before the Himalayas for a start.....
Great insight to combat the current climate change hysteria. The hystericals will not listen, they wallow in ignorance and self flagelation. Fine, don't inflict it on us!
Thank you
What if the Hysteria is actually coming from science denialists who are frantically and hysterically waving their arms, jumping up and down, and screaming that the science is a hoax?
Actual climate scientists are extremely careful in the conclusions that they draw, and characterizing them as "hysteria" is irresponsible.
I'm guessing the scientific content of this video went over your head. It provides further evidence supporting the broadly held scientific understanding of present-day climate change. It will take thousands of years at minimum for geologic processes to remove the carbon dioxide we are presently dumping in the atmosphere. In the meantime, that CO2 will continue to cause warming, because that's what greenhouse gases do. That's why climate scientists are so concerned. Their science-based concerns do not seem hysterical to me.
You can’t reason with any fanatic. Racing religion politics none can be reasoned with.
I thought this was a Dave Chappelle skit
Called " Cracking the ice age " with crackhead cavemen .. 😂 Lol
If the rise of the Himalayas caused an ice age, then why are we not still in one? Are they not still rising and eroding? I'm disappointed that I didn't hear this very obvious question be addressed.
No mention of the Melankovic Cycles. Fascinating.
That’s because the Milankovitch cycles are NOT currently having an effect on Earth’s climate, so why mention it? Moreover, those cycles affect earths climate on 100,000 year cycle, not the last 50 years in which the majority of our climate change has occurred from manmade CO2 emissions. And yes, they do know that the excess CO2 accumulations are from fossil fuels because they carry the C12 isotope signature, which can only come from fossil fuels.
@@ronaldjanert7456 my comment wasn't disputing modern day climate change as I am not a climate denier. The damage brought on by fossil fuels is indisputable. The video of cracking the ice age centered around the building of the Himalyas as the primary driver of the last ice age. Nowhere in the documentary did they mention the Malencavic Cycles. I found that fascinating.
Considering humans have only been burning fossil fuels in any appreciable quantity in the last 200 years how can you say what is actually causing the rise and fall of interglacials and glacial. There have been 33 reversals from one to the other in the last 2.6 million years based on oxygen isotopes so perhaps you ought to just keep trying to learn instead of just buying all the b******* that somehow text dollars are going to be able to fix this
@@douglashanlon1975 It’s not a matter of how long humans have been around burning fossil fuels. What’s at issue is HOW MUCH of it we’ve been burning, and HOW FAST.
Before us, Earth’s Carbon cycle has been in BALANCE (i.e., equal amounts drawn out of the atmosphere vs. How much gets released naturally). that has kept our climate extremely stable for the last 8,000 years, and relatively stable for the last 800,000 years.
The problem is, the Earth can only absorb a certain amount at a certain speed, and CO2 persists in the atmosphere from a 100 to a 1,000 years before it’s circulated back out again. That means that everything extra we emit ACCUMULATES year over year, the same way a bathtub fills up over time and eventually overflows under a dripping faucet when it’s not allowed to drain as fast as it’s accumulating. And that faucet’s been dripping faster and faster over the last 200 years. The greatest amount of accumulation of CO2 has occurred in only the last 40-50 years thanks to Globalization. That’s why it’s risen from 280 ppm to 419 ppm in so short a time.
As for your argument about glacial and interglacial periods, they’re irrelevant to any discussions about our CURRENT climate situation. Why? Because those happen in roughly 100,000 year cycles in response to variations in the Earth’s orbit and axial tilt (Milankovich Cycles) and there are currently no appreciable changes that can even remotely, possibly have an effect on our current climate, and they most certainly can’t explain the speed at which the Earth is heating up. None.
There is no natural explanation for the speed at which global warming is occurring. The science doesn’t match what we’re witnessing.
Moreover, the isotopic signature of the carbon building up in the atmosphere proves the excess CO2 is human-caused because the ratio of C12 is increasing relative to C13, and that can only come from fossil fuels where it’s been shielded for millions of years from the ionizing effects of solar radiation.
@@davidkelter8379 Be careful about demonizing fossil fuels, you are condemning your own existence, few of us would be around without them. It's time to faze them out but they have done vastly more good than bad, saved the whales, we would've wiped out pretty much all the worlds forests for fuel, and the actual *science* (as apposed to popular propaganda) strongly suggests 280ppm CO2 is way lower than ideal.
Never forget about boils law because this explains what happens on mountains they can't start a ice age, its only the orbit of the moon and sun creates ice age
This is unintentional ASMR, Love the using his computer.... cos can cos sin theta eccf graph... what causes co2 to get higher? (cars?)
I can't understand why PBS don't make these available on their website.
That's good for me!☺ I can help you with that
They want money. It's not about education. It's about profit.
@@nohandle62 Who?
It was the Himalayas and the separation of Africa from South America which drastically altered the gulf stream.
Africa and South America separated much earlier (during the Mesozoic), before there Was a Gulf Stream.
But the much more recent creation of the Isthmus of Panama (by volcanism) separated Atlantic from Pacific ocean currents and could have affected the Gulf Stream, and the amount of moisture available to form glaciers in Europe.
1996 oldie but good.
The good old TV shows
It's not all continental uplift
Very likely its a combination of all the things mentioned. We may never be sure.
From 1996. How things change.
I would have thought the mountains would block the cold air from dispersing to the south, thus concentrating it in the northern climes and causing more ice formation from less snow melting. There's snow on top of the mountains because it's colder up there, not warmer. More snow would mean more reflecting of sunlight whereas bare rock would heat more but to what degree if it's pretty cold rock to begin with? Has anyone ever found warm rocks up there, or are they all cold?
They're all cold at that altitude. If they were climbing an active volcano, there would be a pretty good chance of finding warm rocks at high altitude 😂😉
This video is 20 years old...
A bit more than that. Check out the credits; at 55:12, we see, “© 1996”.
So, in 2022, this episode is 26 years old.
The uplift became the death of the Green Sahara?
The last ice age started 40 ma? No, I don't think so.
40k in round numbers. That's colloquial for latest (probably not last) glacial maximum, strictly speaking we *are in the ice ages* beginning aprox. 3M yrs ago to present, with relatively brief interglacial times like now, alternated with longer glacial periods. We are roughly 'due' for next glacial max, 'soon' to a couple thousand yrs out.
We are on the cusp of tech/economic power to prevent next devastating event but CO2 probaly will not do the job, even a lot more than now in the atmosphere, it will at least marginally reduce the risk of mass plant extinction caused by dangerously low CO2 levels (meaning the end of everything that matters) that recent glacial max events have just skirted.
Scientists forget that out of the clash of various opinions, the Truth will emerge!
what year did this come out?
December 31, 1996.
pull tab pabst? that's some ancient classy shit right there..
I'm confused. Should we raise or lower the Himalayas to stop global warming??
We should stop dumping so much CO2 in the atmosphere. That is within our power, albeit very difficult. Raising or lowering the Himalayas is obviously not within our power, but I guess you knew that HA-HA.
It may be that there's nothing we can do to stop global warming, but that doesn't mean we shouldn't try.
So, Ice melts revealing more rock. Rock cools the earth into making more ice?
Or the melting causes flooding and that facilitates moving of the tectonic plates, pushing up more rock and cooling the earth?
Smh I'm just a plumber, but whatever is going on it's cyclical it seems.
Watched nova as a kid in the 70's
The Sun decides everything
The sun decides many things, not everything. If it were up to the Sun, the Earth would have been cooling over the past four decades that we have had reliable measurements of solar emissivity. The present day warming is being caused by increased concentrations of greenhouse gases.
Sometimes the world is more complicated than we would like, but that's why we have science, rather than just intuition, to answer questions. Intuition alone is insufficient to answer scientific questions.
Only one thing in nature colder than ice and that is melting ice 😮 The friction under the plates could have triggered it.🤔
Seems to me that you have air intake below the engine, put it upside down to get through water.
We're the dinosaurs alive during any of the ice ages
You liked my comment but you didnt answer the question
@@susancaleca4796 I quickly looked up "glacial periods in Earth's history" on Google, and came up with the following:
"Scientists have recorded five significant ice ages throughout the Earth's history: the Huronian (2.4-2.1 billion years ago), Cryogenian (850-635 million years ago), Andean-Saharan (460-430 mya), Karoo (360-260 mya) and Quaternary (2.6 mya-present)."
The Mesozoic, which spanned the "age of dinosaurs", from about 252 to 66 million years ago, is NOT included.
This science is sound and accurate, it’s a cycle, very natural. Man’s influence is minor, insignificant.m, there is no climate crisis.
What year was this doc made? Anyone know??
1997
@@kennethfisher7013 thank you
@@miadel5846 that was the copyright date that I saw. Someone else in the comments said 1999.
The obvious place to find that information is, of course, in the •credits•. At 55:12, we see, “© 1996”.
Pick your outcome ice age or what’s currently occurring to our planet’s disturbing warming average temps.
Slowly is relative, mastodons flash frozen standing upright eating sub tropical vegetation, that wasn't exactly slow
Some scientists say we're entering another ice age.
Perhaps. I doubt that our civilization would survive in such a case.😢
The planet has been cooling for near 4,000 years now and during this time there has been a brief heat spike every 1100 years. Like the Minoan Warming, the Roman Warming after it, the Medieval Warming after it, the Modern Warming today came exactly when expected and developed exactly how expected. Today we round the top and begin the slide down the falling side of the spike to a new and even colder period than before, known as the Little Ice Age. As this happens the Eddy Minimum is due, likely in the early 2030's. As we chill once again harvests are expected to fail. Global crop failure is forecast before 2030.
If you were to measure the ice on the planet you would find that there has been more ice in the last few hundred years than in the last ten thousand all added up together. Never in the entire Holocene as this pattern of climate developed. The only time this sort of pattern has ever emerged is when the previous Interglacial Periods came to a close. It indeed does look like the Holocene is ending and today is warmest it will be for the next 100,000 years.
Start a garden.
How could the last ice age have been 40 million years ago when they happen every 26,000 years? 🤔🤔
Many people confuse "glacial period" with "ice age". An Ice Age is a long-term period (up to millions of years) during which multiple glacial and interglacial periods can occur. The program was about the long-term cause of the current Ice Age. They also touched on how glacial/interglacial periods match cyclical changes in the earth's orbit (and axial tilt and precession). Ocean sediment cores indicate that around 8 to 10 glacial/interglacial cycles have happened over the last 800,000 years. But on land, the most recent continental glaciation tended to "bulldoze" away the record of the previous ones (but not everywhere). The most recent cycle lasted about 100,000 years, and glaciation peaked around 26,000 years ago.
If there was rain, rivers and green in North Africa, as we know that there was, and if that scenario presupposes the absence of the current high Himalayan plateau and current high mountains, then if your model is true, absent counting other factors, then the Himalayan situation might be only several thousand years old? The Himalayan mountains are SHARP and the glaciers are NEW, as I look at them. The peaks and even sides and approaches are unworn. The effects of the glaciers are almost negligible. Another subject, but I have examined the Grand Canyon. It just happened recently. The side canyons are brand new. It cannot be explained by gradual wear. The streams in the side canyons, have polished their beds a small amount, but cannot account AT ALL for the presence of those canyons. The streams do not even connect to the plateau. If the Colorado were ten times its current flow it would not begin to explain what I saw in the main canyon. The wear by the river explains NOTHING. The present scenario of lateral erosion by the river is a JOKE. Geological science needs a turn off and re-boot. Start over, but this time with INTELLIGENT PEOPLE, able to scientifically assess what we actually see, not what novelists want to imagine
You should watch more documentaries about the Earth
Is there climate change yes,Is there global warming no!
You couldn't be more wrong
Care to explain hurricane Hillary heading for California. A wee hint, warming of the Pacific.
Because Almighty God is a artist, He makes wow things, like lons tiger's & bear's , & decorates the land scape , 🐾💖🐅 💒
i just love that you tube has to fact check this by united nations no less.
Yeah I saw that , guess humans stopped the ice age , lol
The United Nations is hardly a scientific hub, their motivation is money only, puppets in the hands of dictators.
What if the earth drifted out of orbit further away from the sun, would this cause and ice-age?
We might see a meteorite hit before a polar shift.
No mystery at all. That is, if you know where to find the truth.
I'm curious though that nothing was mentioned about the Milankovitch Theory
They don’t need to. The Milankovitch cycles are irrelevant, because at this time there has been no kind of changes affecting earths climate.
@@ronaldjanert7456 Who is talking about at this time? We are going back millions of years and this would certainly include Milankovitch cycles. That being said, I think it was more than just the Himalayas that caused the ice ages. We are still in one (tail end) actually, but global warming will take care of that.
What if “ice age” is the normal and warm is the out of the norm?
What if...
Another piece of the puzzle.
Why is it they show an Indian subcontinent colliding into the Asian landmass, with a perfect fit ?? Some serious flaws here.