Just a heads up - the elliptical orbit at 2:20 is fundamentally wrong. The aphelion and perihelion are opposite to each other (180°), not at 90°, because the sun is not in the center, but at the *focus* of the ellipse (as per 1st Kepler's law). This is a significant difference, as it gives wrong predictions. The earth is closest to the sun once, not twice per year - currently during winter in northern hemisphere. As orbital speed is faster at closer distances (second Kepler's law), the cold two seasons in the northern hemisphere are shorter if you count the days on the calendar.
Your correction on how to graphically depict the aphelion and perihelion of an elliptical orbit is correct. Good catch. A slight correction to your correction, though. The sun is at one of the two foci of the ellipse (and an ellipse with only one focus is, of course, a circle).
True. But I highly doubt that Dave made the graphic. Also look at the moon size and distance, never mind the distance to the sun. TOTALLY out of scale. So this is just an illustration and not an accurate depiction. However, I concur that perihelion and aphelion should be shown at opposite sides of the orbit.
@@rickkwitkoski1976 He likely didn't make it, but he used it. Of course it is not to scale, a graphic showing the sun, earth and the earth's moon is pretty much never to scale. Try using a to scale graphic showing the three of them without one of them being too large to fit or smaller than a pixel, while fitting on a screen that's not 16,000:9. However, it can be out of scale and still show the correct orbital parameters. There's no excuse for that.
Because of your tutorials, I’m able to get into my ADHD-fueled, obsessive rabbit holes about cool space facts. Thank you, Professor Dave. Real random question: I love looking at pictures of nebulae taken with MIRI/NIR/Ultraviolet cameras to see each detail (unseen stars in the background unobscured by dust, particles, etc). Out of curiosity, What would those nebulae look like from a naked eye POV if hypothetically we were in a spacecraft close to those nebulae? Would we see a lot of dust surrounding those nebulae and light from forming stars lighting up the dust in their centers? I apologize if this question is confusing but I’ve always wondered.
@@ProfessorDaveExplains Thanks so much for the reply! I had always imagined that I’d see something similar to this picture of the Eagle Nebula seen in the link below (Starless version of the Eagle Nebula seen on Wikipedia) en.m.wikipedia.org/wiki/Eagle_Nebula#/media/File%3AM16_Eagle_Nebula_-_Pillars_of_Creation.jpg Looks super scary, but if there’s ANY possibility that we’d get some sort of naked eye natural color POV picture of any nebulae with a probe, I’d love to see it.
if you like astronomy, a real good channel to subscribe too, if you haven't is anton petrov there's a couple others too, but he covers astronomy, physics, and biology with about 1 ten minute video per day.
The density of the pillars of creation Nebula is about 4000 - 5000 particles per cubic centimeter. For comparison, on earth at a 0 altitude : there are about 10 million trillion particles per cubic centimeter (as you can see, many orders of magnitude) ... so if you are inside the Nebula, you wouldn't see anything. Even here on earth, we only obtain those impressive pictures using telescopes and through a long exposure to extract as much light as possible. Besides, this Nebula is between 4 - 5 ly long, to put things into scale, remember that the closest star (after the sun) is about 4.2 ly away ... So, you wouldn't see the Nebula if you are inside it. I mean we are already inside the Oort cloud, we can't see it.
It depends on how close you want to be and what type of nebula/star cluster you want to be in. If you're in a dense area of dust like the pillars of creation you may not see much. If you're on a planet in a globular cluster like the Beehive Cluster, all of the gas has been "used up" so you'd see as far as we can. The difference would be that there are a lot more stars closer to you, so a lot of stars would appear very bright in the night sky. There are many different possibilities, which is 1 reason why astronomy is so fun to me.
Dear Dave, I really love your content. I am going to start studying biochemistry in Oktober, and I often watch your educational videos and your videos debunking pseudoscience. Can i get a comment heart?
The amount of people in the comment section who've already pointed out the error with NOAA and the aphelion/perihelion reaffirms my trust in this channel. The viewers and commentors aren't mindlessly noddihg their heads; they're actively correcting the creator on what they got wrong. You'd never see this on creationist/flat earth channels.
I always wondered how you cope with the amount of sheer ignorance, insignificance, stupidity and spite found in youtube comments. I just dropped by to let you know that I appreciate your videos as they make me understand finer details of already assimilated broad concepts and theories. Thanks for your effort.
Fantastic video, Professor Dave! Now, when we hear climate change deniers claim that we can't discern human impacts on climates versus natural changes, all we have to do is point them to this video. I've tried explaining it to others, but I struggle to make the argument as plainly and simply as you have here. Thanks!
Honestly I think they maybe a good thing. Each kind of Science Professor Dave talks about, some denier comes out and says whatever they say but we can address those deniers and people can learn from it and why those myths are false. If you know what I mean?
But we still don't have exact data to know for certain humans are having a significant impact on Earth's temperatures. It's likely we do but again no exact temps going back hundreds and thousands of years. We see significant changes but not detailed minor changes. So the average temp going up a couple degrees is difficult to see. We just weren't here yet or didn't have the science to do the studies needed. But it is obvious we are having some kind of impact on global warming. How much is to be determined
@@brianstrutter1501 🤦♂️ Just because you don’t know anything about climate science doesn’t mean scientists don’t know We know humans are causing global warming entirely. That’s unequivocal. I have no idea where you are getting your info from, but this global warming is far from natural and looking at paleoclimatology global temperature reconstructions it’s unprecedented. Have you even looked through the scientific literature if I may ask?
Oh my 1:08 I never thought id be the one to find an error of Professor Dave's videos. Its National Oceanic and Atmospheric Administration. I even double checked before commenting because maybe i misremembered because it happens.
When having a discussion about the effects of humans on climate, my father tried to make the claim that the planet gets warmer and cooler naturally in an attempt to downplay human involvement. I showed him a graph similar to that at 7:50 that went back even farther to show how incredibly gradual such natural fluctuations are compared to the obviously rapid jump in temperature we've seen in the past century, and he had no response. Check in with your older family members every once in a while. The damage that organizations like Fox News have done to people cannot be overstated. Come armed with easy to understand graphs like this and fight the propaganda wherever you can.
Why not be honest and show him a temperature graph going back to the last glaciation about 20,000 years ago , it will show the Holocene maximum, 5c warmer than today's, the Roman warm period about 2c warmer than today's and the Medieval warm period about 2c warmer than today, when the ''little ice age'' it was about 2c colder than today which ended in about 1815 and since then we have warmed about 0.7c over 150 years , no rapid jump of any kind. Alarmists always take their data from about 1800 because they don't want to show any previous warm periods when there were no humans burning oil coal or gas. Maybe you can try and explain that to him.
Look at this! A coherent model that explains several different phenomena ALL AT ONCE! My my, I know some gents who would LOVE to have such a thing lol.
" A coherent model that explains several different phenomena ALL AT ONCE! My my, I know some gents who would LOVE to have such a thing lol." i know i would. sadly, all the models i know generally only care about makeup and fashion.
Haven't even watched it yet, but I appreciate this series. For my boomer parents, please incorporate info about anthropogenic climate change and what we have done and need to do in order to right through ship. I use your videos in my classes andove your debates with creationists. Keep up the awesome work.
Milutin Milankovic also made calendar called New Julian calendar (Revised Julian calendar) or Milankovic Calendar which is more precise then Gregorian Calendar.
@@AlbertaGeek Worse, in my experience, most high schoolers *were* taught a lot of things… and taught them again each year, because they completely forgot what they were taught the year before. No doubt many of them forgot most of it after graduating too. Then then come on YT, amazed that "they weren't taught this stuff".
Thanks, Dave. The question I had about Earth's eccentricity, obliquity and precession you answered around the 7:00 mark - that our current climate change cannot be attributed to those factors.
Hey Dave, I think there is a small mistake in the diagram at 2:50. I'm pretty sure the perihelion and aphelion are opposite from each other, as in 180 degrees apart, rather than 90 degrees. It's confused me in the past because depictions are often from a skewed perspective, but for an eliptical orbit, the object being orbited lies on one of the _foci_ of the elipse, rather than at the center of the ellipse: so, the earth is closer to the sun than average for an entire continuous half of the year, and farther than average for the other half. Wikipedia seems to agree. The names and definitions are correct otherwise. It's probably also worth noting that what causes the seasons is mainly the tilt of the Earth, because the change in the distance between the Earth and the sun (over a single year at least) is very slight in comparison as are its effects, although that might be a bit off-topic.
It is fairly easy to see that the tilt is the major factor for the seasons, since the earth is closest to the sun during the northern hemisphere winter.
Really great video Professor Dave. I’ve always been interested in Geology, Paleoclimatology, and how it relates to Human caused Global Warming. So this was nice to watch. Although I would personally change one thing, and anyone can correct me on this, I think it makes more sense to call those “ice ages” glacial cycles with those warmer periods as interglacial periods. With these cycles taking place in an overall ice age. As there have been five major ice ages in Earth’s geologic history (Huronian, Cryogenian, Andean-Saharan, late Paleozoic, and the current one: the Quaternary Ice Age). But I could be getting my terminology confused but I just wanted to address that. Just so it prevents confusion when talking about different types of climate changes in larger geologic time scales. 👍 Edit: Just a small tweak I would make at 1:11 I think it would make more sense to show the National Oceanic and Atmospheric Administration’s climate normals change from using 1981-2010 to 1991-2020 averages for mean annual temperature and annual precipitation and not just look at 1991-2020 absolute values for mean Temperatures and Precipitation for only the month of April. Either way the point still comes across.
Hey professor Dave, love the videos keep em coming. I would just like to ask you if it were possible to post in description the scientific articles from which material was taken (so we can dive even deeper in the topic). Don't know if you will even see this but if you will and you manage to do that thanks a lot!
Doing nothing to stave off man made climate change because climate change occurs naturally is equivalent to doing nothing about gun deaths because “we’re all gonna die someday”. My grandkids are gonna be so mad when(if?) they get older.
I find it fascinating how these little changes in the Earth's tilt and orbit around the sun can change the climate accordingly, even if I'm not studying them in-depth these little tidbits are always fun and useful to know! _plus I can already hear the flerfers and climate change deniers typing in the comments section XD_
@@AlbertaGeek I wasn’t talking about current global warming which is human caused. I was talking about how during glacial-interglacial transitions, the Milankovitch cycle changes Earth’s position in a bit, which warms the climate, than that warming allows co2 to be degassed from the oceans causing a more significant second warming. And leads to a feedback loop. A domino effect. And current global warming could also lead to feedback loops and tipping points. Yes, the Milankovitch cycles aren’t causing global warming today, they are too slow to actually be causing warming and according to them, Earth should be cooling very so slightly, not a dramatic increase in 150 years.
@@PremierCCGuyMMXVI " causing a more significant second warming. And leads to a feedback loop." the planet has multiple feedback loops, most of which are buffers to keep temperatures stable. so most often a change in one factor- say, CO2, would leaf to a chance in another to maintain an equilibrium [for example, increased carbon uptake by plants] the thing is, these equilibrium systems, they tend to act as buffers. buffers keep things the same now matter up you add, up to a point. then adding just a LITTLE bit more can lead to massive changes until a new equilibrium is added. which is why the total amount of carbon we are adding to the atmosphere is very tiny compared to what's already there, but is enough to trigger a massive chnage in equilibrium.
@@vforwombat9915 yes! What did I say that was wrong? The Milankovitch cycles alone aren’t enough to get earth out of a glacial cycle. The cycles allow Earth to warm a bit, than when co2 is degassed from the oceans, earth warms up even more starting a feedback loop that continues until earth’s energy budget reaches stable equilibrium. Yes, the total amount of co2 we are putting in the air is just 3% of the amount of co2 our planet produces. But the system was in balance due to the carbon cycle. Now because we have off setted that balance a little, it’s caused a massive increase in the overall concentration of co2 in the atmosphere by 40%+ in 150 years after being stable for 10,000+ years.
Well folks when someone can explain the existence of a mile of ice over North America (that would take a few years of very cold temperatures) and then mysteriously all that ice melts and raises ocean levels some hundred feet, without one ounce of human influence, then maybe I’ll believe that we humans can actually influence the earth’s climate. The earth’s climate is far more complex than any computer program we could create.
Hmm. Both at 2:37 and 4:00, the elliptical orbit, and thus where more or less sunlight hit Earth, are drawn as if the Sun were at the center of the ellipse, causing 2 perihelia and 2 aphelia per orbit, every 90°. This is inaccurate. The ellipse is off-center. There is 1 perihelion 180° away from 1 aphelion. The drawings at 6:05 get it right. Regarding those last drawings, it should be made clear that the summers & winters marked on them are for the Northern Hemisphere.
Given the complexity of the Milankovitch cycles, it's easy to paint a broad brush and convince people that our sun's cycles are playing a long term minimum effect game while we're to blame for all present day climate changes. But, It wasn’t anthropogenic influence which caused climate change in that period between 20K and 10K years ago. The average global temperature during the Last Glacial Maximum of 20,000 years ago is estimated to be about 46 degrees Fahrenheit. Around 10,000 years ago, the average global temperature is estimated to be around 5.4 degrees Fahrenheit cooler than the present day average global temperature of 59 degrees Fahrenheit or 53.6 degrees. With a 13 degree Fahrenheit average global temperature increase occurring between 20K and present day, and a 5.4 degree Fahrenheit average global temperature increase between 10K years ago and present day, we’re left with an average global temperature increase of 7.6 degrees Fahrenheit between 20K and 10K years ago. Most research indicates a general warming trend over the last 10,000 years, with the most significant temperature changes happening in the immediate aftermath of the last glacial period. According to current scientific consensus, the average global temperature has only increased by approximately 1.8 degrees Fahrenheit since the start of the Industrial Revolution. I agree that we should increase research and development for alternative energy production in hopes of developing a technology that will reduce GHG concentrations. However, unless we can measure for variations in solar activity from Earth’s orbit and spin (Milankovitch (Orbital) Cycles over the past 20K years, we shouldn’t be attributing climate changes entirely or mostly to human activity. To do so, is to suggest that our sun's activity doesn't experience variations within its solar radiation trend extremes.There are influences beyond human activity that are astronomical in comparison.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels. We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels. We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
@@whatabouttheearth Carbon-12 is formed in stars through a process called the "triple-alpha process," where three helium nuclei (alpha particles) fuse together under extreme heat and pressure to create a carbon-12 nucleus. All the carbon-12 found on Earth originated from stars that exploded and scattered the element into space, which then became part of our planet's material when it formed, not from any human directed processes occurring on Earth. A crucial step in the process involves a temporary, unstable state of the carbon nucleus called the "Hoyle state". To form carbon-12, the required heat is extremely high, reaching temperatures exceeding 10^8 Kelvin (around 100 million degrees Kelvin). Carbon-12 cannot be formed on Earth because the extreme temperatures and pressures required for its creation through nuclear fusion only exist inside stars, specifically during the helium-burning stage; therefore, the carbon-12 found on Earth originated from stellar nucleosynthesis and was delivered to our planet through cosmic dust and other processes. Since Earth's environment does not have the necessary conditions to create carbon-12 through nuclear fusion, we're not creating more carbon just redistributing what is already here. Worst case scenario is that we are moving miniscule amounts of carbon from fossil fuels into the atmosphere which is within Earth's natural carbon cycle. According to current scientific estimates, there are approximately 1.85 billion billion tonnes of carbon present on Earth, with the vast majority (over 99%) of it stored within the Earth's crust, leaving only a small fraction in the atmosphere, oceans, and on land. The majority of Earth's carbon is stored in the lithosphere, primarily within rocks like limestone, with the oceans holding the second largest reservoir, followed by the biosphere (living organisms) and a much smaller amount in the atmosphere; essentially, most carbon is found in geological formations, with the oceans acting as a significant carbon sink, while the atmosphere contains a relatively small proportion of total carbon in the cycle. Ocean surface waters and the atmosphere each hold about 2% of the Earth system's carbon reservoirs. Oil, gas, and coal reserves are thought to contribute another 3%. Soils and permafrost hold 5% and 4% of global carbon, respectively, while carbon stored in vegetation adds about 1%.
What would be interesting to know is what is the more powerful effect: global warming or the earths distance from the sun? I doubt this has an actual answer, but it is an interesting thought (for me at least). Also is a runaway greenhouse effect, like what apparently happened with venus, possible on earth or would these changes in orbit counter this?
*"what is the more powerful effect: global warming or the earths distance from the sun"* By global warming, are you referring to human(Co2) induced? *"Also is a runaway greenhouse effect, like what apparently happened with venus, possible on earth"* Yes, it is. But not due to human activity or what happened to Venus. A few billion years from now, the Sun will become larger and hotter as it goes thru it's natural cycle and burns thru most of it's Hydrogen and starts burning Helium. When this happens, Earth will become too hot and life on Earth will become extinct! Venus is a different situation as it's much closer to the sun and has no carbon cycle to sequester carbon out of it's atmosphere like Earth does. It's odd rotation may also have had a role in this!
_"What would be interesting to know is what is the more powerful effect: global warming or the earths distance from the sun?"_ You can just look at the historical data to see that.
The Earth’s distance from the Sun has changed very little to have any meaningful impact on the Climate over the past 150 years. The rise in Global Temperatures in the past few decades is due to carbon dioxide. End of story. A runaway greenhouse effect is unlikely. Humanity doesn’t have enough fossil fuels to turn Earth into Venus. Venus is much close to the Sun and is ~98% CO2 in its atmosphere so it’s hellish. Earth on the underhand has only 0.04% of Co2 in its atmosphere (that my seem tiny but the Earth’s climate is very delegate so just a small rise can have huge impacts as we have seen throughout Earth’s geologic history). The worse Humanity can do to the Earth’s climate is turn it into a hothouse comparable to the PETM 56 million years ago or the Late Permian 252 million years ago.
Nice video except that you should have included how the solar variations are on various times scales, some quite long and powerful, not the just the 0.1% short cycle. Also, you do not include the feedback effect of how the Sun's variation influences the influx of cooling galactic cosmic rays (cooling because they lead to more low level clouds which reflect incoming sunlight). Taken into account, these two factors can account for much of the warming of the past century.
disappointing to see most descriptions of the Milankovitch cycles have been cleansed to promote global warming, or I meant the rebranded ‘climate change’.
It's been dumbed down for the public for decades. None of this is hard to understand. But when their favorite politicians & talking heads are telling them it's all a hoax, none of that matters.
@professor dave explains Hey Dave! Glad to see you address some of these points. One point I've heard from critics of "the climate agenda" is that the earth has had 3x higher proportions of carbon dioxide than current levels in the atmosphere through several times in Earth's history. They note that these times were also associated with an increase in global flora, and they basically argue that this warming cycle is far better for promoting the health and diversity of life on earth compared to a cooling cycle of freezing. What would you say to people who argue that global warming is a good thing?
This has nothing to do with comparing heating to cooling. We need to maintain the climate as it was prior to industrial emissions. We don't want an ice age either. Nobody who studies climate for a living says anything absurd such as this. Rising average temperatures are having catastrophic effects on weather patterns and sea level rise.
@@ProfessorDaveExplains Thanks for the response! It would be a great privelage to get your response to this podcast episode starting at the 12 minute mark ua-cam.com/video/-T14Xzfeltw/v-deo.html where they discuss carbon having an overall beneficial impact on the global environment. Maybe you could do a video on it?
I think a better idea would simply be for you to ignore unqualified contrarian grifting assholes you find on the internet. Carbon dioxide is a greenhouse gas. Industrial emissions of it are raising global temperatures, which is having catastrophic effects. There is zero controversy about that within the scientific community, period.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels. We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels. Nuclear testing in the 1950s changed atmospheric CO2, including adding radioactive 14C to the atmosphere, but after the Nuclear Test Ban Treaty of 1963, we can see "a decrease in 14C" which is really just an increase in 12C/13C from fossil fuels, and we can still use climate proxies for years before nuclear testing.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels. We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels. Nuclear testing in the 1950s changed atmospheric CO2, including adding radioactive 14C to the atmosphere, but after the Nuclear Test Ban Treaty of 1963, we can see "a decrease in 14C" which is really just an increase in 12C/13C from fossil fuels, and we can still use climate proxies for years before nuclear testing.
@@ProfessorDaveExplains I am not trying to fight science, I want to understand it properly. I also agree with 99% of you content. Please send me the name of the paper your curve was published in. Here is one I recommend you to read: Lüdecke, Horst-Joachim, and Carl-Otto Weiss. "Harmonic analysis of worldwide temperature proxies for 2000 years." The Open Atmospheric Science Journal 11.1 (2017). In you record the roman and medieval warm period is not visible, although most reconstructions, including ice core records show them clearly. I also agree that the 11yr Schwabe cycle has very little impact on imcoming solar radiation. But there are far more and more powerful solar cycles than the 11yr cycle apart from the Mylancovic cycles that you haven`t mentioned and are caused by other orbital variations. Furthermore the strength of the suns magnetic field has increased, not decreased since the last decades as an indicator for solar activity. You would also expect a small delay between the highest solar irradiance and themperature spike due to he large heat capacity of the oceans. How dou you explain the Atlantic multidecadal oscilation or the temperature decline during the 1940s?
@@ProfessorDaveExplains I am not trying to fight basic science, I want to understand it. I agree with 99% of your conent. In this case however your graph appears to be far off reality. It does not show any sign of the roman or medieval warm period, or the dark age in between. Please provide me with the source of the paper your the graph is from. It contradicts too much other data, including ice core data from greenland. Here is an examle: Lüdecke, Horst-Joachim, and Carl-Otto Weiss. "Harmonic analysis of worldwide temperature proxies for 2000 years." The Open Atmospheric Science Journal 11.1 (2017). Furtermore I disagree with you by thinking that changes of solar irradiation have a large influence on climate change caused by other strong orbital cycles beside the Milancovic cycles or the very weak 11 yr Schwabe cycle. A decrease of the strength of the 11 yr cycle during the last decades doesnt necessarily mean that total solar irradiance or the strength of suns magnetic field has decreased. How do you explain changes in the Atlantic Multidecadal Oscilation and land temperature decrease in the 1950s with the CO2 record?
You should debate jon zherka about the flat earth. Nobody challenges his stupid points and he is very popular making a lot of people belive in the flat earth
@@waitingfornetwork4989honestly what’s the point? He’s already made tons of videos debunking Flat Earth. Besides we have other science conspiracies that are more pressing such as climate denial or the anti-vaccine movement.
I want to know how fast Bro Sanchez would rage quit on Dave but I know it will never happen and flerfs shouldn't get more time than they're already given
The probability is extremely high, since this is an educational channel with a database of academic tutorials that students watch only when they need to for class. Got it, champ?
Because these videos are designed to be educational and aimed at students. They aren't algorithm abusing shitposts intended to rake in as much money as possible.
@@ProfessorDaveExplains Some of this is also freshman astronomy 101. Atmospheric science is necessary if you're going into the planetary side of astronomy.
Dave and the muppets Science is the obsevation and testing of a subject matter proposing theories along with testing of those theoretical hypothesis. NOW tell me for the sake of these idiots who don't know.. how did the dust particulars come together to form planetesimals since they were to small for gravity to have an effect? How come evolution astronomers models say earth should have no water but we have seas? And lastly why does earth still have a magnetic field if it's billions of years 🧐🤣🤣
So over this current political leadership, the climate averages were 'adjusted' outside the frame of responsibility. By a factor of 3 decades.. hmmm...
No, they just update the climate norms. That’s all. And the climate normal from 1991-2020 across the US was warmer and wetter on average overall climatologically speaking than the 1981-2010 average. Which indicates the US is getting warmer (as well as the rest of the globe) Data is freely available on NOAA National Centers for Environmental information
I can not take seriously any "science" lecture that takes Michael Mann's hockey stick and presents it as factual, sorry. Easy to spot as it stops in the year 2000, making it both false and obsolete.
@@ProfessorDaveExplains Michael Mann's hockey stick graph is visible at 7:53. It is well known that Mann used a large number of dirty tricks to manipulate this graph. There are many analyses on the net of the tricks Mann used, and I refer to those. The obvious intention of this graph is to remove the Little Ice Age and the medieval warming period, which were well-established in science before Mann erased them. The stated excuse was that those happened only in Europe (hard to deny Europe as there is a lot of historical written evidence that they occurred there). However, the medieval warming period and the Little Ice Age happened in other parts of the world, too. For example, there have been climate reconstructions in China based on O-16/O-18 in stalactites, which showed that the medieval warming period and little ice age happened there, too. Mann worked together with Al Gore, and the obvious intention was to create a myth that the climate only changed slowly before humanity started carbon-sinning. Anyway, the graph is quite old now (the graph ends at about the year 2000) and was the basis of Al Gore's climate scare movie. But worse, this graph is very wrong, and wrong deliberately.
@@ProfessorDaveExplains Thank you for adding the coloration to show the medieval warming period and the little ice age in response to the above comment.
@@petersteenkamp Instead of baselessly claiming Mann manipulated the data, why don’t you say what the graph is supposed to show, and what your evidence for that is? You are cherrypicking one 1999 rendition of a graph, while ignoring the real reasons for consensus in climate science. Consensus doesn’t just magically appear because of one graph.
how can anyone know everything you talk about and not believe in God? the sheer intellect in designing such a complex and effective universe within a universe within a universe - it's unparalleled! HalleluYah! Repent and give your life to the Lord!
Just a heads up - the elliptical orbit at 2:20 is fundamentally wrong. The aphelion and perihelion are opposite to each other (180°), not at 90°, because the sun is not in the center, but at the *focus* of the ellipse (as per 1st Kepler's law). This is a significant difference, as it gives wrong predictions. The earth is closest to the sun once, not twice per year - currently during winter in northern hemisphere. As orbital speed is faster at closer distances (second Kepler's law), the cold two seasons in the northern hemisphere are shorter if you count the days on the calendar.
Your correction on how to graphically depict the aphelion and perihelion of an elliptical orbit is correct. Good catch. A slight correction to your correction, though. The sun is at one of the two foci of the ellipse (and an ellipse with only one focus is, of course, a circle).
True. But I highly doubt that Dave made the graphic. Also look at the moon size and distance, never mind the distance to the sun.
TOTALLY out of scale.
So this is just an illustration and not an accurate depiction.
However, I concur that perihelion and aphelion should be shown at opposite sides of the orbit.
" the cold two seasons in the northern hemisphere are shorter if you count the days on the calendar."
that damn groundhog lied!
@@rickkwitkoski1976 He likely didn't make it, but he used it. Of course it is not to scale, a graphic showing the sun, earth and the earth's moon is pretty much never to scale. Try using a to scale graphic showing the three of them without one of them being too large to fit or smaller than a pixel, while fitting on a screen that's not 16,000:9.
However, it can be out of scale and still show the correct orbital parameters. There's no excuse for that.
@@rickkwitkoski1976imagine being a schill for a lying yt “scientist”
Because of your tutorials, I’m able to get into my ADHD-fueled, obsessive rabbit holes about cool space facts. Thank you, Professor Dave.
Real random question: I love looking at pictures of nebulae taken with MIRI/NIR/Ultraviolet cameras to see each detail (unseen stars in the background unobscured by dust, particles, etc). Out of curiosity, What would those nebulae look like from a naked eye POV if hypothetically we were in a spacecraft close to those nebulae? Would we see a lot of dust surrounding those nebulae and light from forming stars lighting up the dust in their centers? I apologize if this question is confusing but I’ve always wondered.
I dunno! I think it wouldn't look like much of anything if you were very close.
@@ProfessorDaveExplains Thanks so much for the reply!
I had always imagined that I’d see something similar to this picture of the Eagle Nebula seen in the link below (Starless version of the Eagle Nebula seen on Wikipedia)
en.m.wikipedia.org/wiki/Eagle_Nebula#/media/File%3AM16_Eagle_Nebula_-_Pillars_of_Creation.jpg
Looks super scary, but if there’s ANY possibility that we’d get some sort of naked eye natural color POV picture of any nebulae with a probe, I’d love to see it.
if you like astronomy, a real good channel to subscribe too, if you haven't is anton petrov
there's a couple others too, but he covers astronomy, physics, and biology with about 1 ten minute video per day.
The density of the pillars of creation Nebula is about 4000 - 5000 particles per cubic centimeter. For comparison, on earth at a 0 altitude : there are about 10 million trillion particles per cubic centimeter (as you can see, many orders of magnitude) ... so if you are inside the Nebula, you wouldn't see anything. Even here on earth, we only obtain those impressive pictures using telescopes and through a long exposure to extract as much light as possible. Besides, this Nebula is between 4 - 5 ly long, to put things into scale, remember that the closest star (after the sun) is about 4.2 ly away ...
So, you wouldn't see the Nebula if you are inside it. I mean we are already inside the Oort cloud, we can't see it.
It depends on how close you want to be and what type of nebula/star cluster you want to be in. If you're in a dense area of dust like the pillars of creation you may not see much. If you're on a planet in a globular cluster like the Beehive Cluster, all of the gas has been "used up" so you'd see as far as we can. The difference would be that there are a lot more stars closer to you, so a lot of stars would appear very bright in the night sky. There are many different possibilities, which is 1 reason why astronomy is so fun to me.
Dear Dave,
I really love your content. I am going to start studying biochemistry in Oktober, and I often watch your educational videos and your videos debunking pseudoscience. Can i get a comment heart?
Flat Earthers are going to love this video xD
Oh no doubt they're getting the marching orders to start trolling.
Is their whole world 1D?
@@Idrinklight44No, that would be the line-earthers.
@@rimbusjift7575lol, don't even believe in 2 dimensions
@@rimbusjift7575lmao
The amount of people in the comment section who've already pointed out the error with NOAA and the aphelion/perihelion reaffirms my trust in this channel. The viewers and commentors aren't mindlessly noddihg their heads; they're actively correcting the creator on what they got wrong. You'd never see this on creationist/flat earth channels.
I always wondered how you cope with the amount of sheer ignorance, insignificance, stupidity and spite found in youtube comments. I just dropped by to let you know that I appreciate your videos as they make me understand finer details of already assimilated broad concepts and theories. Thanks for your effort.
Brilliant as always. Thank you for your service.
I love your contents, can I get a comment heart?
Fantastic video, Professor Dave! Now, when we hear climate change deniers claim that we can't discern human impacts on climates versus natural changes, all we have to do is point them to this video. I've tried explaining it to others, but I struggle to make the argument as plainly and simply as you have here. Thanks!
Honestly I think they maybe a good thing. Each kind of Science Professor Dave talks about, some denier comes out and says whatever they say but we can address those deniers and people can learn from it and why those myths are false. If you know what I mean?
@@PremierCCGuyMMXVI I do, indeed.
Yes, professor Dave talks about actual science. That's why he didn't mention "existential threat" doomsday prediction.
But we still don't have exact data to know for certain humans are having a significant impact on Earth's temperatures. It's likely we do but again no exact temps going back hundreds and thousands of years. We see significant changes but not detailed minor changes. So the average temp going up a couple degrees is difficult to see. We just weren't here yet or didn't have the science to do the studies needed. But it is obvious we are having some kind of impact on global warming. How much is to be determined
@@brianstrutter1501
🤦♂️
Just because you don’t know anything about climate science doesn’t mean scientists don’t know
We know humans are causing global warming entirely. That’s unequivocal. I have no idea where you are getting your info from, but this global warming is far from natural and looking at paleoclimatology global temperature reconstructions it’s unprecedented.
Have you even looked through the scientific literature if I may ask?
Thank you once again, Professor Dave, for making a complicated subject, very palatable and understandable
Oh my 1:08 I never thought id be the one to find an error of Professor Dave's videos. Its National Oceanic and Atmospheric Administration. I even double checked before commenting because maybe i misremembered because it happens.
What did he say, association?
Yikes! Whoops!
You're my favorite UA-cam scientist 😁
Thank you for helping me truly understand class content for multiple classes throughout my college career !
Love the concise, informative presentation. Looking forward to part 2, very interesting!
This is another video series I'll be watching all the way through, thank you Dave.
It's amazing how complex Earth's climate is. Factors from orbital shift to volcanic eruptions are all connected to influence our world.
When having a discussion about the effects of humans on climate, my father tried to make the claim that the planet gets warmer and cooler naturally in an attempt to downplay human involvement. I showed him a graph similar to that at 7:50 that went back even farther to show how incredibly gradual such natural fluctuations are compared to the obviously rapid jump in temperature we've seen in the past century, and he had no response.
Check in with your older family members every once in a while. The damage that organizations like Fox News have done to people cannot be overstated. Come armed with easy to understand graphs like this and fight the propaganda wherever you can.
Why not be honest and show him a temperature graph going back to the last glaciation about 20,000 years ago , it will show the Holocene maximum, 5c warmer than today's, the Roman warm period about 2c warmer than today's and the Medieval warm period about 2c warmer than today, when the ''little ice age'' it was about 2c colder than today which ended in about 1815 and since then we have warmed about 0.7c over 150 years , no rapid jump of any kind. Alarmists always take their data from about 1800 because they don't want to show any previous warm periods when there were no humans burning oil coal or gas. Maybe you can try and explain that to him.
I'd like to have a comment heart too!
Look at this! A coherent model that explains several different phenomena ALL AT ONCE! My my, I know some gents who would LOVE to have such a thing lol.
" A coherent model that explains several different phenomena ALL AT ONCE! My my, I know some gents who would LOVE to have such a thing lol."
i know i would.
sadly, all the models i know generally only care about makeup and fashion.
Haven't even watched it yet, but I appreciate this series. For my boomer parents, please incorporate info about anthropogenic climate change and what we have done and need to do in order to right through ship. I use your videos in my classes andove your debates with creationists. Keep up the awesome work.
Milutin Milankovic also made calendar called New Julian calendar (Revised Julian calendar) or Milankovic Calendar which is more precise then Gregorian Calendar.
Thank you so much for making these videos. You have taught me everything high school failed to.
I see this sort of stupid comment all the time, and I really have to wonder exactly what the commenter thinks high school was supposed to teach them.
@@AlbertaGeek Worse, in my experience, most high schoolers *were* taught a lot of things… and taught them again each year, because they completely forgot what they were taught the year before. No doubt many of them forgot most of it after graduating too. Then then come on YT, amazed that "they weren't taught this stuff".
Thanks, Dave. The question I had about Earth's eccentricity, obliquity and precession you answered around the 7:00 mark - that our current climate change cannot be attributed to those factors.
Hey Dave, I think there is a small mistake in the diagram at 2:50. I'm pretty sure the perihelion and aphelion are opposite from each other, as in 180 degrees apart, rather than 90 degrees. It's confused me in the past because depictions are often from a skewed perspective, but for an eliptical orbit, the object being orbited lies on one of the _foci_ of the elipse, rather than at the center of the ellipse: so, the earth is closer to the sun than average for an entire continuous half of the year, and farther than average for the other half. Wikipedia seems to agree. The names and definitions are correct otherwise.
It's probably also worth noting that what causes the seasons is mainly the tilt of the Earth, because the change in the distance between the Earth and the sun (over a single year at least) is very slight in comparison as are its effects, although that might be a bit off-topic.
It is fairly easy to see that the tilt is the major factor for the seasons, since the earth is closest to the sun during the northern hemisphere winter.
Thanks teach 🙋🙋🙋
Beautiful graphics that explain the situation so well. Thanks.
Really great video Professor Dave. I’ve always been interested in Geology, Paleoclimatology, and how it relates to Human caused Global Warming. So this was nice to watch.
Although I would personally change one thing, and anyone can correct me on this, I think it makes more sense to call those “ice ages” glacial cycles with those warmer periods as interglacial periods. With these cycles taking place in an overall ice age. As there have been five major ice ages in Earth’s geologic history (Huronian, Cryogenian, Andean-Saharan, late Paleozoic, and the current one: the Quaternary Ice Age).
But I could be getting my terminology confused but I just wanted to address that. Just so it prevents confusion when talking about different types of climate changes in larger geologic time scales. 👍
Edit: Just a small tweak I would make at 1:11
I think it would make more sense to show the National Oceanic and Atmospheric Administration’s climate normals change from using 1981-2010 to 1991-2020 averages for mean annual temperature and annual precipitation and not just look at 1991-2020 absolute values for mean Temperatures and Precipitation for only the month of April.
Either way the point still comes across.
Yeah Dave used the colloquial term at one point there. Ice age instead of glacial.
@@Stratosarge "Ice age instead of glacial."
probably didn't want to slow down the video to a glacial pace.
Awesome, very glad you're covering this topic.
Hey professor Dave, love the videos keep em coming. I would just like to ask you if it were possible to post in description the scientific articles from which material was taken (so we can dive even deeper in the topic). Don't know if you will even see this but if you will and you manage to do that thanks a lot!
7:08+ current global warming is not due to orbital variations nor solar variations.
He did address this later in the video but yes you are correct
Thank you, Prof Dave. Good as always. Informative and to the point.
That little opening song/intro is top notch sir.
The charts in these videos are fascinating. I often pause so I can study them.
Thank you for an awesome, scientifically accurate video.
wow this guy knows a lot about the science stuff
Doing nothing to stave off man made climate change because climate change occurs naturally is equivalent to doing nothing about gun deaths because “we’re all gonna die someday”. My grandkids are gonna be so mad when(if?) they get older.
Wonderfully done
I find it fascinating how these little changes in the Earth's tilt and orbit around the sun can change the climate accordingly, even if I'm not studying them in-depth these little tidbits are always fun and useful to know!
_plus I can already hear the flerfers and climate change deniers typing in the comments section XD_
Well it’s these little changes in tilt and orbit that is than amplified by co2 changes thanks to feedback loops. Sort of like a domino effect.
@@PremierCCGuyMMXVI The tilt and orbit has not changed appreciably in the last 100 years. Carbon dioxide emissions, OTOH, most definitely have.
@@AlbertaGeek I wasn’t talking about current global warming which is human caused. I was talking about how during glacial-interglacial transitions, the Milankovitch cycle changes Earth’s position in a bit, which warms the climate, than that warming allows co2 to be degassed from the oceans causing a more significant second warming. And leads to a feedback loop. A domino effect.
And current global warming could also lead to feedback loops and tipping points.
Yes, the Milankovitch cycles aren’t causing global warming today, they are too slow to actually be causing warming and according to them, Earth should be cooling very so slightly, not a dramatic increase in 150 years.
@@PremierCCGuyMMXVI " causing a more significant second warming. And leads to a feedback loop."
the planet has multiple feedback loops, most of which are buffers to keep temperatures stable.
so most often a change in one factor- say, CO2, would leaf to a chance in another to maintain an equilibrium [for example, increased carbon uptake by plants]
the thing is, these equilibrium systems, they tend to act as buffers. buffers keep things the same now matter up you add, up to a point. then adding just a LITTLE bit more can lead to massive changes until a new equilibrium is added.
which is why the total amount of carbon we are adding to the atmosphere is very tiny compared to what's already there, but is enough to trigger a massive chnage in equilibrium.
@@vforwombat9915 yes! What did I say that was wrong? The Milankovitch cycles alone aren’t enough to get earth out of a glacial cycle. The cycles allow Earth to warm a bit, than when co2 is degassed from the oceans, earth warms up even more starting a feedback loop that continues until earth’s energy budget reaches stable equilibrium.
Yes, the total amount of co2 we are putting in the air is just 3% of the amount of co2 our planet produces. But the system was in balance due to the carbon cycle. Now because we have off setted that balance a little, it’s caused a massive increase in the overall concentration of co2 in the atmosphere by 40%+ in 150 years after being stable for 10,000+ years.
Superb, Dave.
Thank you Professor Dave for the video ! Best
this guys the goat
Understandment likes useful informations ツ
Easy and concise.
Well folks when someone can explain the existence of a mile of ice over North America (that would take a few years of very cold temperatures) and then mysteriously all that ice melts and raises ocean levels some hundred feet, without one ounce of human influence, then maybe I’ll believe that we humans can actually influence the earth’s climate. The earth’s climate is far more complex than any computer program we could create.
very nice video!
Would be cool to see a real temperature graph from the space station or a satellite.
Hmm. Both at 2:37 and 4:00, the elliptical orbit, and thus where more or less sunlight hit Earth, are drawn as if the Sun were at the center of the ellipse, causing 2 perihelia and 2 aphelia per orbit, every 90°. This is inaccurate. The ellipse is off-center. There is 1 perihelion 180° away from 1 aphelion. The drawings at 6:05 get it right.
Regarding those last drawings, it should be made clear that the summers & winters marked on them are for the Northern Hemisphere.
I thought we were still in an ice age because there was ice on both poles?
Are climate change deniers next on your debunk list?
Well they are well funded by Koch and Wilkes and many many other fossil fuel corporations. I'm sure PragerU is working on a response video right now.
I sure hope so!
And before this video becomes the new “how we know the Earth is not flat”
Given the complexity of the Milankovitch cycles, it's easy to paint a broad brush and convince people that our sun's cycles are playing a long term minimum effect game while we're to blame for all present day climate changes. But, It wasn’t anthropogenic influence which caused climate change in that period between 20K and 10K years ago. The average global temperature during the Last Glacial Maximum of 20,000 years ago is estimated to be about 46 degrees Fahrenheit. Around 10,000 years ago, the average global temperature is estimated to be around 5.4 degrees Fahrenheit cooler than the present day average global temperature of 59 degrees Fahrenheit or 53.6 degrees. With a 13 degree Fahrenheit average global temperature increase occurring between 20K and present day, and a 5.4 degree Fahrenheit average global temperature increase between 10K years ago and present day, we’re left with an average global temperature increase of 7.6 degrees Fahrenheit between 20K and 10K years ago. Most research indicates a general warming trend over the last 10,000 years, with the most significant temperature changes happening in the immediate aftermath of the last glacial period. According to current scientific consensus, the average global temperature has only increased by approximately 1.8 degrees Fahrenheit since the start of the Industrial Revolution. I agree that we should increase research and development for alternative energy production in hopes of developing a technology that will reduce GHG concentrations. However, unless we can measure for variations in solar activity from Earth’s orbit and spin (Milankovitch (Orbital) Cycles over the past 20K years, we shouldn’t be attributing climate changes entirely or mostly to human activity. To do so, is to suggest that our sun's activity doesn't experience variations within its solar radiation trend extremes.There are influences beyond human activity that are astronomical in comparison.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels.
We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels.
We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
@@whatabouttheearth Carbon-12 is formed in stars through a process called the "triple-alpha process," where three helium nuclei (alpha particles) fuse together under extreme heat and pressure to create a carbon-12 nucleus. All the carbon-12 found on Earth originated from stars that exploded and scattered the element into space, which then became part of our planet's material when it formed, not from any human directed processes occurring on Earth. A crucial step in the process involves a temporary, unstable state of the carbon nucleus called the "Hoyle state". To form carbon-12, the required heat is extremely high, reaching temperatures exceeding 10^8 Kelvin (around 100 million degrees Kelvin). Carbon-12 cannot be formed on Earth because the extreme temperatures and pressures required for its creation through nuclear fusion only exist inside stars, specifically during the helium-burning stage; therefore, the carbon-12 found on Earth originated from stellar nucleosynthesis and was delivered to our planet through cosmic dust and other processes. Since Earth's environment does not have the necessary conditions to create carbon-12 through nuclear fusion, we're not creating more carbon just redistributing what is already here. Worst case scenario is that we are moving miniscule amounts of carbon from fossil fuels into the atmosphere which is within Earth's natural carbon cycle. According to current scientific estimates, there are approximately 1.85 billion billion tonnes of carbon present on Earth, with the vast majority (over 99%) of it stored within the Earth's crust, leaving only a small fraction in the atmosphere, oceans, and on land. The majority of Earth's carbon is stored in the lithosphere, primarily within rocks like limestone, with the oceans holding the second largest reservoir, followed by the biosphere (living organisms) and a much smaller amount in the atmosphere; essentially, most carbon is found in geological formations, with the oceans acting as a significant carbon sink, while the atmosphere contains a relatively small proportion of total carbon in the cycle. Ocean surface waters and the atmosphere each hold about 2% of the Earth system's carbon reservoirs. Oil, gas, and coal reserves are thought to contribute another 3%. Soils and permafrost hold 5% and 4% of global carbon, respectively, while carbon stored in vegetation adds about 1%.
Solar cycle: 12 years
Primary school: 12 years
Coincidence? Truvago
just wanna point out that one of the earths on the excentricity diagram should be INSIDE the circle.
Flat earthers are bout to descend again
What would be interesting to know is what is the more powerful effect: global warming or the earths distance from the sun? I doubt this has an actual answer, but it is an interesting thought (for me at least).
Also is a runaway greenhouse effect, like what apparently happened with venus, possible on earth or would these changes in orbit counter this?
*"what is the more powerful effect: global warming or the earths distance from the sun"*
By global warming, are you referring to human(Co2) induced?
*"Also is a runaway greenhouse effect, like what apparently happened with venus, possible on earth"*
Yes, it is. But not due to human activity or what happened to Venus. A few billion years from now, the Sun will become larger and hotter as it goes thru it's natural cycle and burns thru most of it's Hydrogen and starts burning Helium. When this happens, Earth will become too hot and life on Earth will become extinct!
Venus is a different situation as it's much closer to the sun and has no carbon cycle to sequester carbon out of it's atmosphere like Earth does. It's odd rotation may also have had a role in this!
_"What would be interesting to know is what is the more powerful effect: global warming or the earths distance from the sun?"_ You can just look at the historical data to see that.
The Earth’s distance from the Sun has changed very little to have any meaningful impact on the Climate over the past 150 years. The rise in Global Temperatures in the past few decades is due to carbon dioxide. End of story.
A runaway greenhouse effect is unlikely. Humanity doesn’t have enough fossil fuels to turn Earth into Venus. Venus is much close to the Sun and is ~98% CO2 in its atmosphere so it’s hellish.
Earth on the underhand has only 0.04% of Co2 in its atmosphere (that my seem
tiny but the Earth’s climate is very delegate so just a small rise can have huge impacts as we have seen throughout Earth’s geologic history).
The worse Humanity can do to the Earth’s climate is turn it into a hothouse comparable to the PETM 56 million years ago or the Late Permian 252 million years ago.
Nice video except that you should have included how the solar variations are on various times scales, some quite long and powerful, not the just the 0.1% short cycle. Also, you do not include the feedback effect of how the Sun's variation influences the influx of cooling galactic cosmic rays (cooling because they lead to more low level clouds which reflect incoming sunlight). Taken into account, these two factors can account for much of the warming of the past century.
Milankovitch cycles need to be a container
I always keep my cycle in a container to protect it from the elements.
Prepare for the comment section to be flooded with AGW deniers!!!
actually its “national oceanic and atmospheric administration”
Here before the wrath of David Weiss 😂
Love dave
おはようございます
Dave , send this to our stupid
government , they need educating.
R. UK.
Thanks for sharing your knowledge! Hard to gas light people, when they understand the science. Appreciate you!
disappointing to see most descriptions of the Milankovitch cycles have been cleansed to promote global warming, or I meant the rebranded ‘climate change’.
This is just basic astronomy information, kiddo. Learn something or don't. Nobody cares.
Ur looking forward to watch Oppenheimer brah?
WdYm tHe EaRtH iS fLaT sO tHiS ViDeO WrOnG
Hiiiii
Day 1 of requesting Dave to debunk Cross Examined (UA-cam channel led by Frank Turek)
alright, this topic really requires some coverage and reasonable dumbing down (no offense intended) for the average folks
It's been dumbed down for the public for decades. None of this is hard to understand. But when their favorite politicians & talking heads are telling them it's all a hoax, none of that matters.
@professor dave explains Hey Dave! Glad to see you address some of these points. One point I've heard from critics of "the climate agenda" is that the earth has had 3x higher proportions of carbon dioxide than current levels in the atmosphere through several times in Earth's history. They note that these times were also associated with an increase in global flora, and they basically argue that this warming cycle is far better for promoting the health and diversity of life on earth compared to a cooling cycle of freezing. What would you say to people who argue that global warming is a good thing?
This has nothing to do with comparing heating to cooling. We need to maintain the climate as it was prior to industrial emissions. We don't want an ice age either. Nobody who studies climate for a living says anything absurd such as this. Rising average temperatures are having catastrophic effects on weather patterns and sea level rise.
@@ProfessorDaveExplains Thanks for the response! It would be a great privelage to get your response to this podcast episode starting at the 12 minute mark ua-cam.com/video/-T14Xzfeltw/v-deo.html
where they discuss carbon having an overall beneficial impact on the global environment. Maybe you could do a video on it?
I think a better idea would simply be for you to ignore unqualified contrarian grifting assholes you find on the internet. Carbon dioxide is a greenhouse gas. Industrial emissions of it are raising global temperatures, which is having catastrophic effects. There is zero controversy about that within the scientific community, period.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels.
We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
Nuclear testing in the 1950s changed atmospheric CO2, including adding radioactive 14C to the atmosphere, but after the Nuclear Test Ban Treaty of 1963, we can see "a decrease in 14C" which is really just an increase in 12C/13C from fossil fuels, and we can still use climate proxies for years before nuclear testing.
Predominant icrease in atmospheric CO2 is 12C/13C in the ratio found in plants that discriminates towards 12C, but there is no proportional increase in the radioactive 14C. This is because 14C decays over time. That means that the increase is due to ancient plants and the only ancient plants that are being released into the atmosphere are fossil fuels.
We know damn well that the current warming uptick since the industrial revolution is cause by fossil fuels.
Nuclear testing in the 1950s changed atmospheric CO2, including adding radioactive 14C to the atmosphere, but after the Nuclear Test Ban Treaty of 1963, we can see "a decrease in 14C" which is really just an increase in 12C/13C from fossil fuels, and we can still use climate proxies for years before nuclear testing.
your temperature reconstruction of the last 2000 years is wrong for most of the time period. Did you only use selected tree ring data?
It is not. No, ice cores, and other techniques. Stop fighting basic science.
@@ProfessorDaveExplains I am not trying to fight science, I want to understand it properly. I also agree with 99% of you content. Please send me the name of the paper your curve was published in. Here is one I recommend you to read: Lüdecke, Horst-Joachim, and Carl-Otto Weiss. "Harmonic analysis of worldwide temperature proxies for 2000 years." The Open Atmospheric Science Journal 11.1 (2017). In you record the roman and medieval warm period is not visible, although most reconstructions, including ice core records show them clearly. I also agree that the 11yr Schwabe cycle has very little impact on imcoming solar radiation. But there are far more and more powerful solar cycles than the 11yr cycle apart from the Mylancovic cycles that you haven`t mentioned and are caused by other orbital variations. Furthermore the strength of the suns magnetic field has increased, not decreased since the last decades as an indicator for solar activity. You would also expect a small delay between the highest solar irradiance and themperature spike due to he large heat capacity of the oceans. How dou you explain the Atlantic multidecadal oscilation or the temperature decline during the 1940s?
@@ProfessorDaveExplains I am not trying to fight basic science, I want to understand it. I agree with 99% of your conent. In this case however your graph appears to be far off reality. It does not show any sign of the roman or medieval warm period, or the dark age in between. Please provide me with the source of the paper your the graph is from. It contradicts too much other data, including ice core data from greenland. Here is an examle: Lüdecke, Horst-Joachim, and Carl-Otto Weiss. "Harmonic analysis of worldwide temperature proxies for 2000 years." The Open Atmospheric Science Journal 11.1 (2017). Furtermore I disagree with you by thinking that changes of solar irradiation have a large influence on climate change caused by other strong orbital cycles beside the Milancovic cycles or the very weak 11 yr Schwabe cycle. A decrease of the strength of the 11 yr cycle during the last decades doesnt necessarily mean that total solar irradiance or the strength of suns magnetic field has decreased. How do you explain changes in the Atlantic Multidecadal Oscilation and land temperature decrease in the 1950s with the CO2 record?
_bUt wHaT aBoUT vOlcAnOeS!!?_ /s
Looking at the "newest comments first" I'm surprised no one has been given the pin of shame yet
NO chance lad, I'm "Boracic" (skint)
First 🎉🎉🎉
I anticipate trolls
Always pronounced it ap-helion lol
You should debate jon zherka about the flat earth. Nobody challenges his stupid points and he is very popular making a lot of people belive in the flat earth
Does Jon have a functional map?
@@NinjaMonkeyPrime ofc not but like i said people just listen to him and don’t challenge his ideas
whats the point? they only accept their own „truths“ and ignore every real proof. Because they are crazy con-men. That is all there is to it.
@@waitingfornetwork4989honestly what’s the point? He’s already made tons of videos debunking Flat Earth. Besides we have other science conspiracies that are more pressing such as climate denial or the anti-vaccine movement.
@@PremierCCGuyMMXVI the point is a very large audience
Discuss Earths magnetism. Down 30% since 1800.
Source?
Is it?
If sun is in space, why there is light on earth but not in space?
There is light in space. There's just no atmosphere to scatter it.
Wtf are you guys not going to school??? Im scared of the stupidity of some flerfs
Professor DAVE please have a debate with Jeranism on FLAT EARTH!!
whats the point? they only accept their own „truths“ and ignore every real proof. Because they are crazy con-men. That is all there is to it.
I want to know how fast Bro Sanchez would rage quit on Dave but I know it will never happen and flerfs shouldn't get more time than they're already given
Don christie
a guy w 2.5 million subs gets less than 1% of that in views, explain the probability of that.
The probability is extremely high, since this is an educational channel with a database of academic tutorials that students watch only when they need to for class. Got it, champ?
How often do you watch a tutorial?
Because these videos are designed to be educational and aimed at students. They aren't algorithm abusing shitposts intended to rake in as much money as possible.
You little smart man. You should have said that cities and technology are the main couse. But you chosed a word "human"..
First
Dave stop acting like you know ... tell everyone what your qualifications are and where you gained a phd as a astrophysicist 😂😂😂
This is freshman 101 ecology as written by an ecologist. Try and learn something while you’re here, moron.
You find this topic difficult to understand? Is that why you think the Bible is a science book?
@buildingproject stop pretending you got a science degree. It's sad.
@@ProfessorDaveExplains Some of this is also freshman astronomy 101. Atmospheric science is necessary if you're going into the planetary side of astronomy.
Dave and the muppets Science is the obsevation and testing of a subject matter proposing theories along with testing of those theoretical hypothesis. NOW tell me for the sake of these idiots who don't know.. how did the dust particulars come together to form planetesimals since they were to small for gravity to have an effect? How come evolution astronomers models say earth should have no water but we have seas? And lastly why does earth still have a magnetic field if it's billions of years 🧐🤣🤣
BS
So over this current political leadership, the climate averages were 'adjusted' outside the frame of responsibility. By a factor of 3 decades.. hmmm...
Err what? The climate normals are set for every decade once we have a decade of data. This is based on measurement not political party.
Huh?
Move along folks, nothing to see here - just a sad RWNJ trying to implicate Joe Biden in some sort of conspiracy.
What is "by a factor of three decades" even supposed to mean?
No, they just update the climate norms. That’s all.
And the climate normal from 1991-2020 across the US was warmer and wetter on average overall climatologically speaking than the 1981-2010 average. Which indicates the US is getting warmer (as well as the rest of the globe)
Data is freely available on NOAA National Centers for Environmental information
I can not take seriously any "science" lecture that takes Michael Mann's hockey stick and presents it as factual, sorry. Easy to spot as it stops in the year 2000, making it both false and obsolete.
Huh?
@@ProfessorDaveExplains Michael Mann's hockey stick graph is visible at 7:53. It is well known that Mann used a large number of dirty tricks to manipulate this graph. There are many analyses on the net of the tricks Mann used, and I refer to those. The obvious intention of this graph is to remove the Little Ice Age and the medieval warming period, which were well-established in science before Mann erased them.
The stated excuse was that those happened only in Europe (hard to deny Europe as there is a lot of historical written evidence that they occurred there).
However, the medieval warming period and the Little Ice Age happened in other parts of the world, too. For example, there have been climate reconstructions in China based on O-16/O-18 in stalactites, which showed that the medieval warming period and little ice age happened there, too.
Mann worked together with Al Gore, and the obvious intention was to create a myth that the climate only changed slowly before humanity started carbon-sinning.
Anyway, the graph is quite old now (the graph ends at about the year 2000) and was the basis of Al Gore's climate scare movie. But worse, this graph is very wrong, and wrong deliberately.
@@ProfessorDaveExplains Thank you for adding the coloration to show the medieval warming period and the little ice age in response to the above comment.
@@petersteenkamp Instead of baselessly claiming Mann manipulated the data, why don’t you say what the graph is supposed to show, and what your evidence for that is? You are cherrypicking one 1999 rendition of a graph, while ignoring the real reasons for consensus in climate science. Consensus doesn’t just magically appear because of one graph.
Fire, the element by which the sun exerts its energy, needs what to burn? Oxygen."
How did you pack so much wrongness in one sentence?
@@ProfessorDaveExplains it's a classic meme from flat earther jm truth 🌚
@@cygnustsp Ah gotcha. Yeah they do be saying dumb shit like that.
That and the Electric Universe, where the sun needs a battery :D
LOL.. I see what you did here..
How can Dave who constantly is wrong who put out images and slides that almost all are wrong have so many followers. Are people tht brainwashed?
Name one thing I’m wrong about, sweetie. Or just shut up forever.
Timestamp of the error?
matereo please show what is wrong and then give your evidence not just "I just don't believe it".
how can anyone know everything you talk about and not believe in God? the sheer intellect in designing such a complex and effective universe within a universe within a universe - it's unparalleled! HalleluYah!
Repent and give your life to the Lord!
It's the process of learning science that makes one realize that there is in fact no need to believe in god. Sorry.
Sounds great. Where's your evidence?
@@Talita2006 Cool story, bro! Whatever you need to tell yourself to feel special.
Hey guycohen do you have any evidence for your god besides a book tells me so.
No, it does not. That's a lie you tell yourself because you know zero things about science and you're afraid to die. Sorry, kiddo.