Is Earth's Largest Heat Transfer Really Shutting Down? 

We're just smart enough to screw it up, but collectively too stupid to stop screwing it up.

I live in Greece. December and January are usually the months with our heaviest rainfall. For the last two years we've had barely any rain during these months. Two, maybe three medium to big rains and that's it. I have been forced to irrigate our freshly planted fruit trees DURING WINTER! In the early 2000's I was hitchhiking with a man who had a bunch of farmer friends in the south of France. They used to rely on spring rains to grow hay for next winter, the summer being too dry for such growing conditions. When I hitched with him he told me that all of his friends were seeing a shift in the weather patterns towards heavier winter rains and dry springs. This was one of many recent springs where they were forced to let their cattle graze the spring growth instead of baling it for winter, putting them effectively 'into the red' when it comes to feed production. They would all have to buy in hay for winter feeding.

You start to lose hope when you know that so many smart people have been trying to solve this problem for decades yet nothing fundamentally changes and it only gets worse. 😔

My wife’s grandfather is a lobsterman in Maine. He has been doing this for 30+ years. He says the fishing has shut down this year.

What worries me about this? How difficult it will be to get crops out of drastically changing and/or unpredictable weather. No crops, no meals.

I work in aviation. I have spoken with air traffic controllers who have, in some cases, worked at the same radar facilities, or control towers their entire career. Aircraft perform best into the wind. This is a fundamental rule of aviation. For this reason, runway changes are implemented to always be utilizing the winds to the best advantage. Crosswinds and tailwinds are not ideal, you want into the wind. The tower controllers in many cases have said, you know, back in the 80s, we used the XYZ runway configs maybe, 3 or 4 times per year. In some cases, it's like the east/west flows, where 99% of the time they're in a north flow, or similar. But they in some cases have said, well, now we run east/west flows half of the time we're operating...it's like, how can this be? Have the winds truly changed THAT much in just 20-30 years??? The answer is undoubtedly yes. When you hear anecdotes from everyday people like this, it really hits you, even more than the charts and hard science/data, IMO.

In Japan, rising seawater temperatures are increasing the activity of algae-eating fish, leading to an increase in areas where algae are becoming extinct. The extinction of algae has a major impact on the growth of marine life. As a result, more and more fishermen are planning to protect and regenerate algae.

Often wondered as a Scot why scotlands warming isnt happening... Now I know...cold blob proximity. Only we could miss warning entirely and go straight from cold to ice age 😂

We have half the country that can not even handle basic reality, I feel bad for the future

im from Nova Scotia (near the 'cold blob') flooding has been insane these last couple years (record rainfall according to atlantic ctvnews). this year has seen 4x as many lightning strikes compared to the average of the last 20 years (26,194 in 2022, 6,266 average for the last 20 years. there is a CBC article but i can't post links in comments)

30 years ago in school it was called the Thermo-haline circulation belt. Our instructors warned about the implications of it shutting down. It's a scary thing, especially for Europe.

And they didn't even mention the Beaufort Gyre... a much more intense modification of the AMOC that will dump more fresh water than is contained in the great lakes into the North Atlantic. This usually happens within 1-2 years once it starts and can last for 20 years. It's a known northern hemisphere cooling factor. By not adding this to their story they've left out a huge factor that could cause that "2060" date to look more like 2025.

As a sailor I've been hearing people talk about losing the Gulf Stream and was curious about how that might happen. Thanks for answering literally every question I might have come up with about the subject. Once again you and your great team have hit a home run. 👏 👏 👏

Love the way you broke down the word thermohaline for folks without getting pedantic. Getting folks who are busy with other concerns in life up to speed without getting condescending is going to be key as this all gets more complicated and intrudes into everyone's lives. Well done, as usual. Weathered is a really, really great series that brings fairly detailed science in a way that's understandable to the general public. Thanks for all you do!

What's scary is that the governments of the world know about this and they aren't doing nearly enough to make change

My biggest concern is the regional variation of global warming. Too many pundits talk about global temperature instead of regional changes. It is well known that the southern hemisphere and the tropics haven't risen anywhere near as much as the higher latitudes of the northern hemisphere especially the artic. In the artic tundra the permafrost contains as much methane hydrate as all the fossil fuels burned in the last 150 years. If methane is released from the permafrost it holds more atmospheric heat 20X, than co2, as much as water vapor. I've never seen a timeline on how much temperature rise will release how much methane. Back to regional variation. Most of the worlds ecosystems/ vegetation zones have a huge shift in seasonal rainfall with dry seasons being part of the cycle. Agriculture depends on these specific rainfall patterns. We in the US especially east of the Mississippi have more moderate high and low range.. The other fear is for Asia. 8 majors rivers come from snow melt of the Himalaysian mountains. If there was only a 20% drop, China, India, Pakistan and Southeast Asia would suffer lower food production. But like you said changes in the AMOC is also a big threat.

Having been a small fruit grower - blueberries, raspberries, blackberries, elderberries, highbush cranberries, gooseberries, plus a wild grove of mulberries - I have watched in 20 years a shift of a full hardiness zone in our area. The problem is that it's not a "clean" increase, we still get oddball very late freeze events in spring that two years ago caused a LOT of my fruits to have substantially decreased yields, both due to freeze damage and it being too cold for pollinators for nearly two weeks right in the early spring blooming season. Plus I've seen an increase in various insect pests, and a massive and unpredictable increase in fungal diseases. It's going to be worse with forestry and tree crops, as these changes may mean that you have a disease or pest that suddenly invades areas with mature trees, wiping them out. For example, they found out that cold winters can massively reduce emerald ash borer populations, but we've had enough warmer winters that even the Great Lakes States are getting hammered. Ash trees may become extremely rare in the United States due to this. So this is a huge problem. I cannot understand why so many farmers are voting for politicians that are blocking any steps to deal with climate change, because whether it's farmers in the Colorado River Basin (20 year mega-drought that may just be ending, though it's more likely a reprieve not a pardon) or farmers having to plant more southern varieties of blueberries that are inferior to the more northern ones in taste, but can survive extended heat waves better (look up Rabbiteye versus Northern Highbush Blueberries), farmers can see climate change in action over half a lifetimes of farming (20 years). As an example of how devastating this can be to farmers and crops, it's not just having to change Blueberry species, but you end up pulling up or losing mature bushes that could have lived 50 years and had over 20 years of optimal yields, and the new pushes can take 5 years to return to full yields. Assuming no drought, because freshly planted/younger bushes have less of a root system, and are more susceptible to water shortages. Look how devastating a workplace injury or layoff that causes a family to lose months of income can be - and then consider surviving a five year financial hit. There are dozens of other examples, and it's not just in the United States but all over the world agriculture will require massive, rapid changes to cope with this. Then when you have overpumping of aquifers, like in the Colorado River Basin, you end up with a collapse when that water becomes prohibitively expensive, if the dry period continues. Look up "food riots". Drought and famine have been events that have ended civilizations. Plus famine gives you more disease, and nations go to war to make sure "their" people don't starve. You've got all four horsemen covered...

First thing is to get governments to understand that YOU CAN'T EAT MONEY.

James Burke revealed this in his series "After the Warming", presented in the late 80's.

Even dogs are smart enough not to poop in their own food bowl (but not humans). Perhaps we should put them in charge for a while... It never ceases to amaze that greed and stupidity are at the heart of almost every one of human kind's greatest challenges.

I will forever remember my Ecology 101 professor in college way back in the early 00s discussing this system and our impact on it, and telling us that every major disruption of the thermohaline circulation is strongly correlated with mass extinction events. The whole classroom gasped in recognition of just how dire this is, and went silent.

It also means the record warm oceans we are seeing now will get exponentially hotter as all that tropical heat will have no where to go. If the oceans die the land dies.

I fear the younger generations. We're leaving them a mess and a much harder life than we've had.

Very good. A lot of sceptic don't understand that 70% of the ice in antarctic is fresh water and 70% of that sits above land. So two things contribute to sea rising. Fresh water floating on more dense salt water and ice above land is straight addition rather than displacement for ice floating

"For years, we operated under the belief that we could continue consuming our planet's natural resources, without consequence. We were wrong. I was wrong."-Vice President Becker, _The Day After Tomorrow_

Stefan Rahmstorf is one if the leading scientists working on the AMOC so I take note of what he says. The paper sighted at the end with it's alternative explanation for the Cold Blob does not account for the marked rise in sea temperature off the US East Coast which models predict for a slowdown of the AMOC.

For the USA peoples, "the wheels on the bus go round and round."

This is the apex of being both smartest creatures on earth and dumbest at the same time

this video should be a required watch

Climate migration leading to conflict is the most worrisome in my opinion. Subsaharan Africa, South and Central Asia, China, and parts of Europe are likely to be far less habitable. This amounts to more than 25% of the global population. We humans are not very welcoming to migrants now and the numbers are nowhere near what they will be in 100 years.

@3:04 I was obsessed with that movie all throughout middle and high school. It's scary how that movie seems to become reality to some degree the more time that passes and still 20 years later, haven't changed those old habits, but rather embraced them and made things even worse now than then.

12:08 we're actually here in the Gulf Stream where a lot of sharks gather. ... precedes to jump into the ocean and swim

As a Dutch person I am used to mild weather in general, mild summers, mild winters. Although when I was a kid in the 1980s the winters in my country were much more harsh than these days. People here love ice skating on natural ice. This has been done for so many years on canals, lakes and even rivers at time. In the province of Friesland, if weather conditions allowed, we organized a 200km ice skating tour across 11 cities (also known as the "11 cities tour", or "Elfstedentocht" in Dutch. The last time we could do this, and the whole country was sitting in front of the tv watching this event was in January 1997. So imagine, it has been 26 years ago that this thing could be organized. The only plus side of the Gulf-stream slowing down or stopping is that we would be able to skate more often. But in general I doubt it will be good for Western Europe if this ocean cooling/warming effect will diminish.

thank you for clarifying that the AMOC =/= the gulf stream and that if the AMOC slows the gulf stream won't disappear (unlike some recent clickbaity news articles)

If I had a nickel for every time I heard the phrase 'tipping point'... well you get the idea

I love this channel. I always learn something new, and never feel marginalized as a Black woman. I feel normal. Thank you PBS.

I could tell you one that happened over 20 years ago...my dad has been a bayman his whole life. In the late 90's all the lobsters died and my family went broke- my parents had to do everything they could to get together and work that issue out. It was sad the day my father got rid of his lobster boat. He still digs clams and hes almost 70.

I love when scientists just say fuck it and name something “cold blob” 🤘🏼

The AMOC slowed about 600 plus years ago and Europe suffered with extreme cold for about 450 years. 1400’s to the 1850’s Europe was much colder. Rivers froze and crops died. Everything is so intertwined. Colder, warmer, wetter, windier, and drought are all considered climate change. Climate stability is what has let us flourish for 50,000 plus years. Climate stability is not part of our future.

We’re sitting in a place where sharks gather… Ok we’re in the water 😕🤨

That cold spot could be the stagnation of the water currents in AMOC. When currents are moving the cold water gets pushed around, but when they slow down the cold water stays in place and gets colder and colder.

"When the last tree is cut, the last fish is caught, and the last river is polluted; when to breathe the air is sickening, you will realize, too late, that wealth is not in bank accounts and that you can’t eat money." Aboriginal North American saying.

You know, I’m something of a cold blob myself…

I like that the first thing your scuba friend tells you on your intro to the dive location is that there are plenty of sharks.... 🦈🦈🦈😂

Remember who did this. When you’re hungry, eat the rich

Ice core samples do show that just before the last Ice Age, there was a warming, that became a "run away warming" and then suddenly, the temperature dropped by as much as 6º within two years, then it rose again, up and down, extreme highs to extreme lows, within two or three years. After a few cycles, less than twenty years altogether, the temperature dropped drastically and didn't came back up again, until the Ice Age was over. It was theorized at that that the warming had caused the collapse of the ocean currents as you have described.

Random Television Line: “People call me Dave.”

This is why Day After Tomorrow is my favorite natural disaster movie.

Can you imagine how immensely powerful hurricanes will become if the cooler north Atlantic waters stop flowing south?

You know what's also bad for the climate? Nukes.

I feel like the first half of the 21st century will be known as The Period of Innovation, while the second half with be The Period of Repair or correcting mistakes. Undoubtedly the 21st is a time period of unparalleled learning and discovery, we do not always make the best decisions with that knowledge.

It has a lot to do with Greenland melting, and dumping vast quantities of cold, fresh water into the ocean in one place relatively quickly (at least on a geological timescale).

Its scary to see the whole scientific comunity putting the likelyhood of the scary tipping points closer and closer… the fact that I still have to convince many people around me that this is real and we will all suffer the consequences, triggers me even more

It's amazing that the climate is changing. We need to stop this.

Famine, drought, heatwave deads... we will all experience very nasty horrible things

Never even remotely I’d be living through and witnessing the first part of the 6th extinction. I believe it will go much faster than people realized due to a domino effect of interdependent systems collapsing. And the Darwin Award goes to ✉️ …. Homo sapiens! Congratulations 🎉

Living in one of your “riskiest regions” of the u.s. I have a front row seat to climate change, yet we are continually amazed our neighbors and politicians can deny anything is amiss. We can no longer deny to ourselves that we need to leave for our health and quality of life is suffering even though our income is tied to the area as well as our families. My anxiety cannot take hurricanes, floods, tornadoes, drought, heat domes, power failures, and now wildfire especially in our elder years like we are now. This is getting worse each and every year. I have actually encouraged my grown children to escape if they possibly can because I love them so much. Escape will be harder and harder as time marches on there will be nowhere to go but staying here is not an option.

We live in the Great lakes region. The intense swings will bring some crazy storms through here, especially when it comes winter

I live in Northern Indiana and remember when I was a kid having snow in October, now we are lucky to have winter with any snow at all. Global warming is happening so much faster than ANYONE wants to admit. For anyone today that has young kids consider them the last generation survive on the planet. We have 50 years max but realistically its going to be more like 25 because in about 10 years time the amount of warming will have gotten so bad that runaway effect will have increased so much that about 10 or 15 years after that the earth WILL have become unlivable to the point that unless you are living underground you would not be able to survive. With everything that is going on in the world today and the fact that WW3 seems to be right around the corner, I have come to the sobering reality that maybe this particular planet and its species just wasn't meant to make it.

My concern about this situation is that whilst the media and governments play lip service to change, they're ultimately more concerned with profits, which drives consumption, and so far from seeing any changes in emissions, we see that year on year they rise.

As a Norwegian who just had his first child this truly scares me. We have always heard of what would happen if it collapses. It was told almost as a scary story around the bonfire. But that its becoming a reality within my lifetime is truly sobering. I think we as a country are about to have a wake up call as it slams in our face. I can try to help prevent it, but as a citizen... As a father. I have no idea how to prepare.

There is so much I need to process from this video, probably because I'm unfamiliar with the topic. I have a pocket notebook with me, and I'm jotting packets of info down. What a complex topic!

I'm more concerned by the prospect of our magnetic field flipping. Perhaps we should be preparing GPS systems to deal with such an event?

Hopefully the world leaders can all fly on their private jets next year to talk about how we need to do something to save the planet despite every world leader having a nearly unanimous consensus on this topic.

What is amazing is no matter what the universe throws at the earth life continues in the end. With all what we`ve seen in past history it seems unreal life is still going on despite what has happened in the past.

I live in NC. I saw a documentary once that said the Gulf Stream brings tropical warmth, and without it NC might have weather like Wisconsin.

The planet will be just fine, humanity on the other hand…

This area is colder because that is where all the icebergs start out when they melt off the glaciers in Greenland. That's why it's getting colder as the melting is speeding up.

The earth "just" came out of an ice age! Temperatures fluctuate. Expecting the earth to maintain the same temperature is crazy.

I have found evidence (unpublished) that the 8200 Yr Cooling Event was part of an unexpectedly complex series of events which included a 110-year collapse of the AMOC. More recent research shows that in Northern Ireland that collapse caused rapid outcomes including cooler than 0°C every month of the year, beginning immediately after... most likely making all of northern Europe uninhabitable in those times. No crops, no leafy trees for mammal foraging, etc. Scientists should evaluate the surface current coming down the Davis Strait as a potential forcer.

I realise you are a US company but it would be great to cover the whole world, including Southern hemisphere in your maps/predictions. We're concerned about this in Australia as well. I particularly wanted to see about the monsoon belt dropping but Australia was cut off the map.

We cannot do anything to change the earth cycle, all we can do is observe and adapt...

I have been suspecting that the monsoon (we call it the Wet) has already begun to drift to the South in Australia.

I find troubling that it's a constant reference to emissions. I find more intense heating without a commensurate cooling due to rapid development of cities, deforestation, development by means of defacing natural spaces instead of 're-development' (removing and rebuilding in existing areas). Case in point is the massive growth of Texas cities which are linked by air and massive highway systems. Ranches and green areas being stripped bare to add apartments, concrete and asphalt pads and so on, plus add all the air conditioners compressors/heat pumps running all day and night- the heat domes are just like those on top of a computer's CPU which require massive cooling systems. Computers have those our our cities don't. You can cut emissions, but politicians and citizens need to come up with a better way to accommodate human growth/housing and commercial construction. They typically won't until 1) it's a crisis and 2) not on my watch/pass it to someone else. Even Chinese cities are at record temperatures more than ever before- and its not cars- it's massive, heat-retaining/heat-producing sprawl.

We still have tons of work to do on educating the general population. The other day, I just had a conversation where a guy said that carbon is good for the environment and that the hole in the ozone layer was a good thing because "even a fireplace has a flute! Hot air needs someplace to go!" It was very disheartening hearing someone my age have that loose of a grasp on science.

I am glad to hear about the cold blob. This is the first time that I have heard so much about it. The behavior of our marine life is very apparent this year.

Hi PBS Terra, thank you very much for doing this detailed and coherent video, this style of presentation satisfies my desire for consistency coherence and logic, that subtle combination of hypothesis and evidence, those complex relationships between the many conflicting and contributing factors, elements and forces. Given that the two primary forces, heat and gravity, interact in global dynamic systems with materials of differing heat capacity and density a high level of complexity is to be expected and so accurate predictions very difficult, what cannot be contested is that there will be significant changes in global climate and there is a history of such changes are sometimes dramatic. Calculations of temporal probability are really of academic interest only, knowing exactly when these changes are occurring is more than enough for us to respond appropriately. Cheers, Richard.

I think that an AMOC collapse can lead to a serious reduction in phytoplankton growth, because of ocean water stratification preventing the upwelling of nutrients from the deep. Not only are phytoplankton key producers of organic molecules - food for organisms at higher trophic levels (e.g. for the fish we eat) - in the ocean biome, but they are also responsible for about 50% of the oxygen production on Earth!

I'd love to hear about impacts like this on pacific regions.

In 5 years we're gonna have a very rude awakening about how wrong we are about tipping points being the distant future. Oh it'll be 2050 I swear lol.

Great example of excellent science communications!

And now you see why it pisses me off that people refuse to even consider building in reinforced concrete.😠

There also is going to be a effect this winter. Even today there is smoke in the air from Canada. Black absorbs heat. It also radiates it. IN 31 days Anything above 45 Degrees latitude will radiate more heat than it absorbs in those huge tracks of burn areas. Those areas are down wind from The Bearing sea and the Gulf of Alaska. So might get colder than -40 in Yellow Knife this winter. Why no F or C? -40 is the same on both thermometers. If it dips into the Great Lakes. Those will freeze over. All of them? Then then the ice breaker will be working non stop next winter.

Climate change will cause immigration, or climate refugees, to move from the hotter regions to the cooler regions. The real question no one can answer, how will climate change affect food production?

Not only do the oceans retain heat, but they're also one of the biggest carbon sinks on Earth.

Seams like a self fixing problem, the amac stops the north freezes and it starts up again

has this cold blob moved over the UK, our summer has been pretty poor.

Biggest fear is the connection the AMOC has on other key tipping points. Aside from the cooler northern hemisphere, it's not going to stop overall global warming, in fact given the statement about the carbon sink, it's going to make it worse. Potentially much worse. In other words, the AMOC could be the lynchpin tipping point which locks in the rest.

Ask anyone who owns a heated pool how much energy it takes to keep it warm. Now imagine that on the scale of the world's oceans. For many years the oceans have been a "buffer zone" or "time delay" between what we have tossed into our atmosphere over the decades and the warming we are starting to feel today. When climates all over the world change at the same time, well: Enjoy everyday you have left.

Thank you for such a clear exposition

"that's why the process of scientific discovery and debate are so important" - except when we talk of COVID and Climate Change. Overall a very good report. Thanks

I am so pleased you were able to collaborate with the shark study team. My daughter and I watched that together. Climate collapse is a little heavy for her age group, but we share what we can.

I live in Germany and really prefer not to experience Canada like weather, as my latitude actually should experience if it weren’t for the warming effect of AMOC…

I'm just happy two sisters are telling part of this story. Intelligence over beauty.😊❤

This is the scariest thing coming. Around 11,000 BCE an ice dam broke and flooded the Mackinsey River in Canada with a Black Sea-sized lake of Laurentide glacial melt. The Mackensie carrlied that north into the Arctic and then ocean currents took it down past Baffin Island into the Labrador Sea, disrupting the AMOC. This started the Lesser Dryas, many centuries of ice age, a reverse-course when the world was warming.

Too little too late i believe we have already tipped over the edge. The poles are shifting which i think will cause extreme winters and summers. Its 110 f in Texas we are burning up down here we got phoenix weather which is crazy.

If only humanity were a more intelligent species.

The most obnoxious thing about climate change is that it's an incredibly easy, damn near effortless problem to fix, but we're so obsessed with fossil fuels that we just can't handle the concept of a world without them. Humanity is soooo fucked, and I am all here for it.

I'd love to hear about impacts like this on pacific regions.. I'd love to hear about impacts like this on pacific regions..

Thanks for a very intersting explanation. What totally astounds me, or perhaps it should not really) is that despite all the overwhelming evidence that we ALL can see before our very eyes there is STILL nothing being done to change our part and there are still "experts" arguing that the evidence "may not" be proof of the trouble ahead...... . THAT IS THE TRULY SCARY aspect of the whole situation. The Naysayers say Nay and they hold sway..... but very VERY soon the Itoldyousos will have the last "hurrah" as we all go down with the sinking ship. Now we need a study very quickly to see what the current year of 2023 massive forest fires around the globe have done to CO2 levels all that solid carbon of which Trees are made has been released in one very hot summer and is still ongoing.......