Greenhouse and icehouse periods have played crucial roles in the evolution of life on Earth, forcing biotic adaptation and turnover at various spatial scales across time. Over the past 720 million years, icehouse conditions preferentially occur when supercontinents are assembled and continental volcanism wanes. Conversely, greenhouse conditions occur when certain gases accumulate in Earth’s atmosphere.
Throughout our planet’s history, Earth has fluctuated between hothouse and icehouse states. Today, our home is supposed to be in a period of global cooling, but human emissions of greenhouse gases have caused this change. Hotter periods make up about 70% of the past 2.5 billion years and are called Greenhouse Earth. They can last hundreds of millions of years, with CO2 levels rising. The Late Cretaceous ‘greenhouse’ world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without.
The Earth has been in a greenhouse state for over 70% of its history, largely ice-free, even at the poles. Evidence for abrupt climate change is readily apparent in ice cores taken from Greenland and Antarctica. Earth’s hottest periods, such as the Hadean, late Neoproterozoic, Cretaceous Hot Greenhouse, and PETM, occurred before humans existed.
The Earth is currently in an “interglacial period” of our ice age, where the planet is somewhat warmer and glaciers have retreated closer to the poles. The astronomical conditions necessary for another Ice Age are slowly moving into place, and there are not one kind of Hothouse Earth.
📹 When will the next ice age happen? – Lorraine Lisiecki
Throughout Earth’s history, climate has varied greatly. For hundreds of millions of years, the planet had no polar ice caps. Without …
Has the Earth ever been hotter than it is now?
The planet has experienced significant heat spikes over the past 100 million years, including the Cretaceous Hot Greenhouse and the Paleocene-Eocene Thermal Maximum. The history of hot temperatures is influenced by indirect clues such as rocks, fossils, and ocean sediments. However, thermometers and weather stations only exist for a small portion of Earth’s 4. 54 billion-year-long life. During the Hadean period, Earth’s collisions with other large planetesimals, including a Mars-sized one, likely created the Moon.
This likely melted and vaporized most rock at the surface. Scientists estimate early Earth conditions based on observations of the Moon and astronomical models, with the planet estimated to have been around 2, 300 Kelvin (3, 680°F) after the collision. No rocks on Earth have survived from so long ago.
Will global warming trigger an ice age?
Earth’s natural cycles and greenhouse effects may delay the onset of the next ice age, expected within the next 10, 000 to 100, 000 years. Some theories suggest that global warming could trigger an ice age by disrupting ocean currents, particularly the Gulf Stream, leading to dramatic cooling in Europe. A warming planet is less likely to wind up in an ice age, as the Earth is constantly going through warming and cooling cycles. Scientists predict that we will hit another big chill sometime in the next 10, 000 to 100, 000 years, covering much of the world, including Europe and North America, in a thick sheet of ice.
However, some researchers argue that the heat trapped in the Earth’s atmosphere from the greenhouse effect will offset this cooling, preventing the Earth from entering another ice age. Another theory suggests that global warming might actually lead to another ice age, as warming temperatures disrupt ocean currents, particularly the Gulf Stream, which redistributes warm water from the Gulf of Mexico to northern Europe.
Are we in a period of climate crisis?
Climate change is a global crisis that is causing environmental degradation, natural disasters, weather extremes, food and water insecurity, economic disruption, conflict, and terrorism. Rising temperatures are causing sea levels to rise, the Arctic melting, coral reefs dying, oceans acidifying, and forests burning. Business as usual is not enough to address the irreversible costs of climate change.
Human activity is producing greenhouse gas emissions at a record high, with billions of tons of CO2 released into the atmosphere every year due to coal, oil, and gas production. A ten-year summary of UNEP Emission Gap reports shows that we are on track to maintain a “business as usual” trajectory, highlighting the urgent need for collective action.
Will there be a mini ice age in 2030?
The published opinion of an ice age in the next 15 years is false due to the lack of reports and confirmation of such an event. Climate and space science data do not confirm such a situation, and there is a low probability that it will occur due to accidental changes. Some parts of the world oppose the concept of global warming, arguing that even if global temperatures rise, environmental temperatures may not rise too much.
How close are we to 1.5 degrees?
Human-induced warming reached 1°C above pre-industrial levels in 2017, and global temperatures are projected to reach 1. 5°C around 2040. The stylized 1. 5°C pathway involves emission reductions starting immediately and CO2 emissions reaching zero by 2055. To better understand the long-term trend, it is necessary to average temperature anomalies over 20 to 30 years. Global temperatures have reached 1. 1°C above pre-industrial levels in 2011-2020 and 1.
5°C above pre-industrial levels in September 2023. However, the Paris Agreement does not specify how many years, datasets, and time periods should make up this long-term trend, causing different conclusions from scientists, governments, and groups about when Earth passes this critical threshold.
How hot will the Earth be in 2050?
Climate change is a significant issue, with global temperatures increasing by about 1°C since 1880 and projected to rise by 1. 5°C by 2050 and 2-4°C by 2100. The National Oceanic and Atmospheric Administration (NOAA) reports that average annual global temperatures have steadily increased since the 1960s. Nineteen of the 20 warmest years have occurred since 2001, and it is likely that the coldest year moving forward will be warmer than the warmest year in the 20th century.
Researchers from the University of Wisconsin-Madison analyzed temperature records from a statewide network compiled by the National Climatic Data Center, revealing that Wisconsin has become 2°F warmer and 4. 5 inches wetter since the 1950s, with the greatest warming during winter and the largest precipitation increase during summer.
Could humans survive an ice age?
Humans, a species that emerged around 300, 000 years ago in Africa, have been around the world since then. Some populations remained in Africa, avoiding the full effects of the cold, while others moved into Europe’s cold, glacial environments. Other hominin species, including Neanderthals in Europe and Denisovans in Asia, also existed during the ice age. Both groups disappeared before the end of the ice age.
The survival of humans during the ice age is believed to be due to our adaptability and the use of social and communication skills. Interestingly, humans did not hunker down during the ice age, but instead moved into new areas.
Is Earth in a warming or cooling period?
Earth’s climate is warming, but media often questions this, interpreting new studies as contradicting previous research or data as conflicting with established scientific thinking. A recent story from NASA’s GISS Surface Temperature Analysis (GISTEMP) highlighted a short-term cooling period in 2017 and 2018, stating that short-term cooling cycles are “statistical noise compared to the long-term trend”.
This led to queries from readers about whether a significant period of global cooling could be or already underway. The article highlights the need for continued research and analysis to confirm the long-term trend of global warming.
What climate period is the Earth currently in?
Earth is currently in an icehouse state, with ice sheets present in both poles simultaneously. This state results in lower greenhouse gas concentrations and global temperatures. Earth fluctuates between glacial and interglacial periods, with the size and distribution of continental ice sheets varying dramatically. This fluctuation affects regional climatic conditions, affecting the range and distribution of many terrestrial and oceanic species. The Earth’s climate has transitioned from warm to chilly intervals within life-sustaining ranges over thousands to hundreds of millions of years.
The Quaternary Ice Age began approximately 2. 58 million years ago, with an ice sheet in Antarctica for 34 million years. Earth is now in a clement interglacial period that started around 11, 800 years ago. Earth is expected to phase into another interglacial period, such as the Eemian, between 130, 000 and 115, 000 years ago.
There is a strong correlation between low CO2 levels and an icehouse state, but this does not mean that decreasing atmospheric levels CO2 is a primary driver of a transition to the icehouse state. Other solar, geologic, and atmospheric processes may also play a role in driving Earth into an icehouse state. Potential drivers of previous icehouse states include the movement of tectonic plates and the opening and closing of oceanic gateways.
Examples of oceanic current shifts due to tectonic plate dynamics include the opening of the Tasmanian Gateway 36. 5 million years ago, which separated Australia and Antarctica, and the opening of the Drake Passage 32. 8 million years ago by the separation of South America and Antarctica. The closing of the Isthmus of Panama and the Indonesian seaway approximately 3 to 4 million years ago may also contribute to Earth’s current icehouse state.
One proposed driver of the Ordovician Ice Age was the evolution of land plants, which gradually removed CO2 from the atmosphere and replaced it with increasing levels of O2. Another proposed driver of the Quaternary Ice Age was the collision of the Indian Subcontinent with Eurasia, forming the Himalayas and the Tibetan Plateau. Under this paradigm, unweathered silicate rock CaSiO3 reacted with CO2 to produce CaCO 3 (lime) and SiO 2 (silica), which were transported to the ocean and taken up by plankton, which then died and sank to the bottom of the ocean, effectively removing CO2 from the atmosphere.
What climate era are we in?
The Anthropocene refers to the era during which humans have become the most influential species on Earth, causing significant global warming and changes to various aspects of the environment, including land, water, organisms, and the atmosphere. The term was coined in the 1980s and popularized in 2000 by atmospheric chemist Paul J Crutzen and diatom researcher Eugene F Stoermer. The Anthropocene is widely accepted as a new geological epoch, as humans have had a lasting and potentially irreversible impact on Earth’s systems, environment, processes, and biodiversity.
Are we exiting an ice age?
Earth is currently in an “interglacial period” of our ice age, where the planet is slightly warmer and glaciers have retreated closer to the poles. This warming is happening much faster than the natural “glaciation cycle”, which has occurred around every hundred thousand years. The last ice age peaked around 21, 000 years ago, followed by 10, 000 years of warming that brought us to the climate we know today.
During this time, global temperatures rose by about 6° Celsius (around 11° Fahrenheit) and the amount of carbon dioxide in the atmosphere rose by nearly 50. This is the main greenhouse gas responsible for today’s climate change.
📹 The Last Time the Globe Warmed
Imagine an enormous, lush rainforest teeming with life…in the Arctic. Well, there was a time — and not too long ago — when the …
Let’s not forget when there were so many huge plants (including the massive ‘scale trees’) that too much carbon dioxide was being sucked up, leading to the reverse of global warming and causing an ice age. Those same plants also increased the oxygen level so much that Arthropods increased significantly in size, leading to three metre centipedes and eagle-sized dragonflies. What a time the Carboniferous period was!
Can somebody please help me with my question? So if I’m getting this right… It took 14,000 years to reach the interglacial maximum temperature… if we reach our glacial maximum every 100,000 years, then our next glacial maximum will be Ed 86,000 years? Of course, that would be if humans were not altering the climate… Am I getting this right? Any help with my answer would be much appreciated, thank you.
I am conservative and proud of it. Climate change is not a hoax and we all know this and most of us actually agree. I think this a great chance for creativity. It starts with the small things cleaning up after yourselves and getting involved in groups. Planting trees, healthier dieting, reduce driving, bike riding. I post this because we are in fact all in this together.
This made so much sense to me. I always thought/believed that climate change was just a natural process but once I heard the nifty fact that scientists studied air bubbles in Antarctica, I changed my mind. We should be cooling but are not due to the amount of pollution we create. Makes perfect sense!
According to the geological survey, we have stagnated on the low end of the interglacial temperature scale. In other words we are far from reaching the past high temperature. Given that the tilt/wobble of axes is receding from its peek of 24.5 degrees 11,000 years ago (end of the ice age) to present 23.5 means we are headed toward cooling. And according to the geological graph, we are like on a washboard with temp’s bumping up and down. The tilt of axes is on our side, proven to cool temperatures in time. To say warming is the cause of the past 150 years is ridiculous. We have been in this stagnant interglacial period for hundreds of years. But as the degree of tilt recedes toward 22.1 degrees, we will be cooling.
If the world has gone through periods where the oceans rose dramatically and then fell dramatically. Then what is the problem with it happening again, even if it is caused, more or less, by humans? Yes, it would hurt island nations and coastal regions, but the changes would happen gradually over about 100 years, according to this article. That’s a good amount of time to come up with a way to either evacuate these places or defend them against the ocean; and enough time to follow through with the plan/plans. Also, something interesting about rising sea levels, the Sahara desert used to be a massive jungle when the ocean level was higher. So, we would lose current coasts for new ones, and, potentially, gain some arable land from deserts; also the land under the ice sheets, we would get that as well.
That my blood curdled… I need to try to work this out, thinking about this. I feel like i humilate myself. Because kids in this article already is doing things like that. Mavelous👍 I respect their behavior! And I’m trying to do things like that, taking baby steps. It doesn’t have to be a great deal! Actioning in life is something that all of us can do! That’s the name of the game!
My question is: in the article it mentions the cold climate of orbital cycle comes every 100,000 years 1:49. The last ice age was 20,000 years ago 0:07 2:18, so shouldn’t the change last for another 50,000 years or around that before it reverts? 🤔 how come the warm temperature peak occured about 6,000 years ago 2:39?
Mrs Richards “I paid for a room with a view !” Basil: (pointing to the lovely view) “That is Torquay, Madam.” Mrs Richards: “It’s not good enough!” Basil: “May I ask what you were expecting to see out of a Torquay hotel bedroom window? Sydney Opera House, perhaps? the Hanging Gardens of Babylon? Herds of wildebeest sweeping majestically past?…” Mrs Richards: “Don’t be silly! I expect to be able to see the sea!” Basil: “You can see the sea, it’s over there between the land and the sky.” Mrs Richards: “I’m not satisfied. But I shall stay. But I expect a reduction.” Basil: “Why?! Because Krakatoa’s not erupting at the moment ?
If there is a climate change it might be better to focus on preventing damage then on CO2 emissions. The anthropogenic distribution on the global CO2 emissions are between 2 % and 3,5 % which couldn’t even be cut efficiently with current climate goals by just 0,5 %. There are planty of factors that cause a climate change as you mentioned. It is very likely that climate would change even without human interference. If that’s the case we should prioritise the adaptation to changed circumstances. I can not help up but seeing the climate goals to be just politically wanted.
Gradual longterm cooling since 1000s years. Suddenly with industrialism upward warming curve. So, what is so special with the warming trend in our time compared to the warming trends of the Minoan age, the Roman age and the Medieval warming? Those warming trends were transitory. How d’you know the last warming tendency is not transitory, too? How do you know the contemporary warming is due to Industrialism, and not due to natural factors like the earlier warming periods? In which case it would have happened regardless of human impacts?
It’s important to note Earth has seen 5 ice ages, we are currently in one, the Quaternary Ice Age. Each ice age has glacial-interglacial cycles effected by Milankovitch cycles. It’s important to note that the shape of Earth’s orbit, known as eccentricity, the angle Earth’s axis is tilted with respect to Earth’s orbital plane, known as obliquity; and the direction Earth’s axis of rotation is pointed (wobble), known as precession. These work together to a point where sunlight in summer isn’t strong enough to be hot enough to melt winter ice and as much mentioned in the article caused ice gain. Greenhouse gasses also play a big role. But we are currently in an interglacial of the Quaternary ice age known as the Holocene which began over 11,000 years ago. The current Quaternary ice age began over 2 million years ago. People tend to confuse ice age with glacial cycle but we are still in an ice age. The most decent interglacial was the Eemian 130,000 years ago and Earth was actually a bit warmer than the current Holocene (tho sea levels were much higher according to NASA GISS). But with higher greenhouse gasses by humans, we may end the Holocene epoch or even the whole Quaternary time period all together and form the Anthropocene epoch or even the Anthropocene time period.
I have a question: Why do you not mention the thermohaline circulation, which does match up with previous cool periods? How does runaway warming not cause another ice age due to all the freshwater which is being dumped into the oceans by the melting glaciers, causing complete collapse of the circulation?
While we obviously need to curb out Carbon use why can’t we also use this water to our benefit? As an American I see wildfires in California and it strikes me as crazy since there is a giant ocean there. Maybe states(countries)need to build (green) desalinization plants. It just seems that there isn’t enough money to be made so therefore progress isn’t there.
We are in the middle of an ice age actually, called quaternary glaciation, and it didn’t end 10k years ago as You said, but it’s ongoing. What happened 10k years ago was the beginning of an interglacial period within the ice age (i.e. A period of warmer climate usually lasting 10k to 50k years within an ice age)… If the ice age actually finished 10k years ago the earth would be ice free and average temperatures would be closer to 20c…..
When? Do you mean when it begins? Or do you mean when huge ice sheets have already been built up? I guess a fullblown ice age will have begun when summeers are gone and winter weather prevails the whole year. Til then we have to go through a Transitioning phase which, by the way, might already have begun.
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1:05 straight to the ‘Co2 is the MAIN driver’ lie huh? lets just completely ignore that Co2 FOLLOWS changes in temperatures in the geological past I guess… “Our analyses of ice cores from the ice sheet in Antarctica shows that the concentration of CO2 in the atmosphere follows the rise in Antarctic temperatures very closely and is staggered by a few hundred years.” – Sune Olander Rasmussen “In their seminal paper on the Vostok Ice Core, Petit et al note that CO2 lags temperature during the onset of glaciations by several thousand years but offer no explanation. They also observe that CH4 and CO2 are not perfectly aligned with each other but offer no explanation. The significance of these observations are (sic) therefore ignored. At the onset of glaciations temperature drops to glacial values before CO2 begins to fall suggesting that CO2 has little influence on temperature modulation at these times.’
Kind of a click bait title. Not saying climate change is any less important, but still. I was expecting to get an answer. She never even said that the next ice age wont happen or even if they do know or not. I’m assuming it’s implied that at this rate it wont, but why never actually answer the question you proposed?
I liked the article, but it doesn’t answer the question, and there is research for when the next ice age can occur. Of course it depends on several factors, like CO2, CH4, and H2O vapor; however, the main driver are still the Milankovitch cycles you mentioned (the greenhouse gases just delay it). Also, it might be better to use stalagmite research (like the work of Dr. Jonathan Baker and I) for recent climate change, since gas bubbles can move freely in recent ice layers, and that messes up your data and conclusions. Too bad you people will probably never read this though.
The CO2 pumped into the atmosphere by the burning of fossil fuels is undeniable. However, I do not see many people talking about the need for CO2 is order to prevent a glacial period (or maximum). Surely, an ice sheet covering a huge portion of the northern hemisphere is worse than a sea level rise of 10 meters OVER SEVERAL MILLENNIA… I.e. a centimeter a year… you think the communities and population wouldn’t just slowly move back over the course of THOUSANDS OF YEARS?
Yeah i think manier times that one the earth will end coz of us harming the mother earth badly. So to prevent this i am taking a small initiative that i will grow one tree a year. And yep i’m an indian so it written somewhere in our holy-book that it is also good for our ancesters too. Good bye and keep it up for making such inspirational vidos ❤❤
To answer the question, NO. I think any action helps, I’ve been trying to learn botanical science and practicing it ever since became aware of the world, since I grew up in a place with heavy pollution. even the math is simple. given circumstances that people might be in a hardship, if only half of earth’s population spend 1 hour in their weekend to plant a young tree and maintain it, we would have 3.75 billions or so grown up trees in a few years. that’s not much, but imagining doing that repeatedly?
My question is, even if we manage to keep carbon emissions down, history tells us the planet does have its own cycle and this is an issue humanity will have to face regardless… … what do you think about that? Do we suppose technology will save us? Either we adapt to the new conditions which are inevitable or become extinct… I’d love to hear thoughts on this…
Given that a lot of countries still rely on fossil fuels for energy, the largest world powers would have to agree to give every developing country the technology and knowledge required to use alternative energy solutions (such as nuclear or solar). It would be the single greatest act of charity the world would never know. Taxing countries that use coal power doesn’t work either since they’re generally too poor to afford better energy solutions in the first place, so they’re unlikely to care if a rich country tries to bully them over it. It’s like a few rich snobs ending up in an elevator with a bunch of less well off people who have gas problems for 12 hours and the rich snobs declare that anyone who passes wind has to pay everyone else $10. The gassy people have nothing to lose by dropping their guts and are more inclined to do so out of spite for the rich idiots who may seek to extort them. Perhaps the ideal solution is to find ways to pull carbon back out of the air at the same rate that it’s being pumped into the air from coal and other fossil fuel power plants? Of course, even then you’d have to convince the world’s governments and corporate CEOs to implement them, so you might have just as much luck outright replacing coal power with solar, nuclear or wind power. (So not much luck at all.)
Here’s an idea how about we get companies to go back to using glass bottles and paper bags Used to glass bottles could be taken back to stores for money, then they would be washed thoroughly, then sent back to the bottling companies to be refilled. Broken glass could be remelted back into bottles. Also chemicals plastic is rumored to kill testosterone. Affecting men and women a like.
Co2 is not the only green house gas we need worry about. There are many including methane which is far more potent than co2. If you want to do something about like Climate change one of the best things you can do as an individual is go plant based, animal agriculture is one of the leading causes of climate change and by stopping your consumption of animal products you will make a real difference!
Ice ages and interglacial eras have nothing to do with CO2 concentrations. Remember, when CO2 is high during an interglacial the world cools, and when CO2 is low at the glacial maximum, the world warms. Yes – counterintuitive, isn’t it… So what controls and modulates the interglacial cycle? Answer – orbital cycles and ice sheet albedo. Milankovitch orbital cycles provide the basis, but the surface feedback mechanism is albedo, not CO2. The albedo effect as measured in the high NH latitudes is orders of magnitude greater that any CO2 effects. Ice ages would continue indefinitely, if the high albedo of the ice-sheets could not be lowered. So what lowers ice sheet albedo? Answer – dust. It is a fact that sudden dust-storms lasting for millennia, lower the ice sheet albedo just before every interglacial. Why these dust-storms suddenly happen, is fully explained in the science paper: Ice Age Modulation by Dust and Albedo. This dust production process is caused by CO2, but not in the manner you might imagine. See these Ice age modulation articles, based upon the science paper: youtube.com/watch?v=99EHhiKG1ZI youtube.com/watch?v=3Fm2KMMrtXI R
You didn’t answer the question. But I get that that’s not the point, so my question is why does it matter? Global cooling would have just as great an effect on the environment and cold temperatures are more detrimental to human health. A rise in sea level of less than a meter every hundred years is something coastal communities can probably keep up with and it would probably be cheaper than some alternatives.
What’s important to keep in mind is that a quantitative difference in the rate of change can mean a qualitative difference in the effect of that change. E.g. if the change is slow enough for a species to adapt, it adapts. If it’s faster than it can adapt, the species is gone. Which in turn might cause other species to go extinct, even if they could’ve otherwise adapted.
We always hear about how balmy it was in the Arctic during this time, but then what was life like at the equator during this period? Deserts? Unlivable and devoid of life? More tropical rainforests? I’d like to know what the rest of the planet was experiencing when temperatures were so much higher…
The transient mantle plume under the Faroe Shetland basin at the end of the Palaeocene caused massive uplift of the ocean floor (minimum of 700m to 1000m) and cut off the ocean circulation to and from the north at the time. This has been mooted as one of the contributing factors. Also, a warming sea cannot hold as much CO2 so there is a chicken and egg scenario wrt CO2 and warming.
Good one! But one thing I would have liked to seen addressed is the matter of sunlight. Even if the poles go tropical they still have to contend with having dramatically unequal lengths of daylight during the winter and summer. It could be that massive decomposition every winter had something to do with it. At the very least it makes me wonder if this with where the deciduous tree comes from.
Polar dinosaurs would be an interesting topic. Many species of very different forms were present within the arctic circle, including hadrosaurs, tyranosaurs, dromeaosaurs, and ceratopsians. We know some of those species to not have any evidence of feathers, going as far as to have evidence supporting the contrary (hadrosaurs, I’m looking at you). These must have been some pretty resilient animals to have been so successful in that region.
Interesting article. However, I heard no mention of the Milankovitch cycles, which have to do with 3 changes in the earth-sun relationship. They are precession, a cycle of about 25,000 years, axis deviation, over about 40,000 years, and orbital changes, which cycle about every 100,000 years or so. These changes have significant effect on climate change over long periods. They have no noticeable effects over short periods of, say, 3 or 4000 years, but over the much longer term, they are very significant.
Please do one on the medieval warm period when the Vikings lived in Greenland and, the historical record from the Arctic where people travelled to 81 degrees 29 mins north in the year 1923, the furthest ever recorded. Also, should ye have the time to examine it, the events in Europe in the early part of the 1700s, when the Seine and the Loire dried up so much that people were able to walk across them.
Warm oceans release dissolved CO2 and the forams die off and quit taking it out of the ocean. The released CO2 and higher temperatures stimulate rain forests. But the warmer atmosphere expands and holds more H2O and the vapor rising to higher increases cloud cover and precipitation. Albedo goes down, ocean staying constant but the clouds condensing over the continents reflect more heat back into space. Decreased solar insolation reduces the health of the rain forests, and the temperature which has been forced to an extreme now rebounds vigorously causing dramatic cooling. The oscillation, as one might expect will reverse direction from more extreme conditions. Add sensitivity to initial conditions and the long term predictions become … uncertain. We can’t be certain of the balance between positive and negative feed backs, but we can be certain that there will be extremely swift and extreme fluctuations.
I think the Amazon rain forest was everywhere in the world when the PETM warming occurred. Sometimes I do really believe that Earth can recover once human activities suddenly disappeared on one day. Imagine a dry land where an entire forest is cut down, nature will repair itself. But damn I have to admit, a tropical Earth seems to be better then cold and warm seasons in the Arctic circle.
Thank you for a serious presentation given briefly. I am 70 and when I was a student at Cambridge the serious academic opinion which was widely communicated in public was that Earth was heading for a serious cold period if not new Ice Age which would be triggered by a short and minor warming caused by pollution.. That was 50 years go – but 50 years is really very short time and I would like an explanation sometime – from you or anyone else serious – at to why opinions have changed. so dramatically. Could it be politics rather than serious science?
What they don’t seem to want to say is that about 20 million years ago india crashed into asia and raised both the tibetan plateau and the thirty thousand foot high himilayas. The huge amounts of weathering that happened as a result of this efficiently scrubbed the excess co2 from the atmosphere and has led to the ten and twenty thousand year cycles of glaciation.
And the last time this occurred there weren’t billions of humans who lived in coastal areas and relied on ocean life for food. Amazing some can’t grasp the difference. Still the most common argument I get from climate change deniers and skeptics is that the climate is always changing. Yeah, of course, but not on this scale, at this rate, for this reason…
The last major warming was the Eemian, 115, 000 years ago . That was the interglacial warming that occurred before the Holocene, which is the current interglacial warming we live in today. The Eemian was about 2c hotter than now at its maximum and lasted in total about 15000 years before the glaciers returned.
temperature rises, ice melts, sea levels rise species die, oceans reach desalination point, species die, temperature drops, ice age begins, species die, oceans levels drop, temperature rises, oceans reform basically its a circle, but the factor that’s changed is humkinds introduction into the loop and its ability to impact its environment like no other species has been able to
Question: as you point out that primates evolved with forward facing eye, thumbs…, I’m sure other animals at this time also evolved from earlier forms ! Now today we have had reports of animals (dolphins, chameleons and others) popping up with new species! Could the rise in current temperatures also kick off another evolution for the animals that humans haven’t killed off yet ???
At least in the last 8yrs they have some theories as to what caused the poles to freeze after the global warming events. It was the ocean currents stopping due to the salinity being to low from all the ice melt. Once the oceans stopped moving warm water from the equator to the poles they refroze and eventually enough water froze to raise the salinity again and the current restarted and the warming cycle began again.
I would like info on the current ice age. What has or is causing the very lengthy cooling trend? Why are we in an inter glacial period now? How long might this cool climate trend persist when it resumes? What geographical areas will be most survivable when the ice sheets have returned? How will the shape of continents change with the loss of ocean waters to ice?
This is my thought and question. The earth has gone through several extinction events many of which happened long long before humans showed up. I realize that what humans do now is speeding global warming up but realistically, is there really anything that we can do to stop the earth from going through another extinction event, global/partial ice age, tropical earth phenomenon and the like? Are these events not just part of the earth’s life cycle? I’m not saying stop recycling, stop pollution reduction measures, etc. I’m just saying the earth is going to do what the earth does and I think that humans have a very large God complex if we think that we can do anything to control these natural events.
such a strange conservative final statement…if science teaches anything, its that observing the constant change that occurs in the universe and learning to understand and accept it, modern humans are fortunate to live during a temperate and calm climate point, but its been changing and will change and our effects are making that happen more. we observe that and understand it and then maybe for the first time ever in life’s history, a life form can choose how it adapts before the change occurs instead of having to adapt and evolve afterword’s.
During that Paleocene-Eocene Thermal Maximum (PETM), what happened to marine mammals, arctic mammals, and penguins? Had these evolved yet? I would think they could’ve adapted well except they’d have a hard time near the equator. It sounds like a broad section of latitudes would be hard to live in, too hot, but that elsewhere, it would be doable, although uncomfortable. — Much of the USA and Canada is going through a heat wave this summer with temps over 100°F. My city is oddly having lower than average temps for over a week, due to rain coming inland from the Gulf Coast. But otherwise, we’d be above 100°F also, so the rain is mostly a blessing. However, this means greater risk of tropical storms and hurricanes, an annual risk for the Gulf Coast.
It’s just amazing that the world, changed and for some reason changed again and for another reason it will change. Hmmm no bad humans to cause said change but still have to point out bad humans now. Why can’t you just present something without the alarmist bad humans crap added in or is that just a funding thing.
Presently we are some of the lowest levels of CO2 for the last 600,000,000. I truly doubt based on history and physics that we should be concerned with warming. Much more concerned with cooling as the magnetic fields in the sun cancel and solar activity drops like that in the last Mini Ice age. need to buy some land further south like……Arkansas.
I love how the worst spin they could put on global warming is “some species didn’t make it, but many others thrived”. Umm, last I checked, that’s what happens as a matter of course. Nothing is static, change is the only constant. Also, our lack of coral fossil records doesn’t mean a lack of corals. We just don’t have a complete record of their prevalence and success.
My global warming climate science class mentioned Antarctica moving to the South Pole contributed to the cooling at the thermal maximum’s end. Since ice forms easier on land, any cooler temperature could more easily form ice and kickstart the Ice-Albedo feedback. Did that contribute a lot, or was it more minor/uncertain?
It is the same as during the kt disaster with small fragile birds surviving. In snowball earth hot springs kept life afloat. Even when the galcial ice even extended to the equater and small spots would open in the ice enough so that photosynthetic life remained. Just small ocean holes would open in the ice from storms. Some weather would continue even if subdued.
I’m a little confused about how dissolved CO2 in the ocean depletes the availability of carbonates. CO2 + H2O -> H2CO3, and then the protons dissociate from the CO3(-2), right? Doesn’t that increase the amount of carbonates? I get that those protons make the ocean more acidic, but isn’t there more carbonate now, too?
Thanks for clarifying that the rate of CO2 increase is significantly faster than even PETM. Certainly I am concerned about survivability, and ability for species to adapt, and the risk of permanently losing biodiversity. Its not clear that we understand the tipping points to be willfully modifying the earths atmosphere for some perceived benefit.
##################################### Most people don’t even realize the globe warmed greatly during the greek Minoan period (2000BC). Polar bears survived. There was a strong warming period during the rise of the Roman empire. 50BC to 400AD. Polar bears survived. There also was a warm period in the 11th-12th century. Even the Brits could grow more southern European grapes. Crops were planted in Greenland. Polar bears survived. Do you see a natural pattern here?
I go with massive wild fires. After the extinction if you think about it there would have been luxuriously growing plants everywhere with nothing to eat them piling up dead branches and leaf litter. This would continued until big herbivores evolved to eat trees and such. Thick forests would have piled up all over until voi la lightening or maga triggered fires which would have raged everywhere until evolution brought about enough plant eaters to achieve equilibrium and their habitat found itself with the proper balance once again.
Sea levels were higher? Did you know that the water displacement of 3 oz of liquid water is the same displacement as when that same 3 oz becomes frozen. You can do a very simple experiment at home. Step 1: measure out 1 cup of water, put it in the freezer and let it freeze. Step 2: get a bigger pitcher and place another 1 cup of liquid water into this pitcher. Step 3: put the frozen ice cube into this pitcher with the liquid water. Step 4: watch the water level once you put the ice cube into the water and record it. The water displacement of when the ice cube was frozen compared to when it melted will not change. Also, how do you know that once Antarctica melts that the permafrost ground won’t absorb a lot of that water? And lastly, if you increase the temperature of the planet you also increase the humidity. If water from the ocean is turned into vapor more often and is kept in the air then you have less H2O in the oceans. In short, if you have more H2O in the air, then you have less of it in the ocean. I think if you want to talk about rising sea levels you might want to consider how much water displacement we have today with all of the maritime trade we do and all of the other devices we have put into the ocean i.e. wind farms, fish farms, etc.
This article is untrue. The last time the world warmed was a period named the “Medieval Warm Period”, which lasted from roughly 1000AD to roughly 1350AD. It was so warm during this period that there were vineyards in northern Scotland and a thriving wine industry in England. While there were certainly warm periods that were much warmer, and much longer in far earlier times, such as the era that produced the dinosaurs, the “Medieval Warm Period”, and the subsequent “Little Ice Age” which ran from roughly 1400AD to the early 20th century, unequivocally prove that the primary cause of climate change on earth is the ever changing patterns of solar irradiation. The idea that CO2 is a pollutant is ludicrous. CO2 is plant food, and without it, nothing on earth would be green.