[kiwichick]

@ sg.....fair enough .....but how much land is there above 1000 metres?

thinking of my own back yard the land above 1000 metres is largely steep , generally rocky mountains.....infertile and difficult terrain

[SeaGypsy]

Enough. Personally I totally doubt the vision of billions fleeing northward to the newly fertile polar tundra. Like animals do in the wild in response to climate change, they start dying & moving uphill. There are some with the mobility to get to possibly large sanctuaries from wherever they are now, but that ability will rapidly break down as global air travel diminishes & lifeboat countries tighten borders or close them.

Then there are oversimplifications like Australia being a big cookpot with a 2-3 degree rise, when in fact the whole central ranges, where it is often over 40 Celsius, is also average around 1000 meters altitude, can not get anywhere near WBT 35+ because the humidity never gets anywhere near high enough, & rainfall & flooding has dramatically increased with warming, causing a massive upsurge in both wildlife & grazing production. Alice Springs has about 20,000 less people now than the MacDonnell Ranges sustained before whitefellas showed up.

Ibon & I are on exactly the same page on this. The tendency here, as with most discussion on the topic, is towards grand, sweeping visions of doom, which ignore natural reality, display geographic ignorance & disconnect from nature. In fact the picture is infinitely more complex & difficult to describe or predict.

[Ibon]

The tendency here, as with most discussion on the topic, is towards grand, sweeping visions of doom, which ignore natural reality, display geographic ignorance & disconnect from nature. In fact the picture is infinitely more complex & difficult to describe or predict.

Why we have such a complex dynamic being reduced to sweeping visions of doom? The sub culture of doom warriors here browse the internet and copy and paste links and claim to be learned and objective. They sit down every day and search exactly those topics and studies that reinforce their already fixed opinions, in fact they start to specifically search only the most extreme positions because their fixed positions of our civilization spiraling down the toilet has to seek out ever more dramatic forecasts and predictions.

These folks are like clams. They are isolated in their cyber shells, they are filter feeders, they filter out the most extreme positions and eject these sweeping visions of doom out of their anal sphincters and spew these excretions all over this site in the form of link after link of guaranteed, bonified and certain doom and extinction coming our way.

A peak behind the cyber wall reveals their true identity

[vtsnowedin]

then there is all of Antarctica and much of Siberia/Alaska/Canada/Scandinavia where even under the 6C climate disaster the summer temperatures will still be quite tolerable for human beings.

But as you move further north, agriculture becomes harder to do because of the longer stretches of darkness. Then you need to rely more and more on hunting which only works with very low population density. So if everyone crowds the poles, it would be very very messy (long-pork being the main foodsource).

No as you go North the growing season has longer and longer days and the winter has longer nights. If the days between last and first frost are increased by climate change Agriculture in Northern areas will become easier and more varied in the number of viable crops.

[Tanada]

Enough. Personally I totally doubt the vision of billions fleeing northward to the newly fertile polar tundra. Like animals do in the wild in response to climate change, they start dying & moving uphill. There are some with the mobility to get to possibly large sanctuaries from wherever they are now, but that ability will rapidly break down as global air travel diminishes & lifeboat countries tighten borders or close them.

Then there are oversimplifications like Australia being a big cookpot with a 2-3 degree rise, when in fact the whole central ranges, where it is often over 40 Celsius, is also average around 1000 meters altitude, can not get anywhere near WBT 35+ because the humidity never gets anywhere near high enough, & rainfall & flooding has dramatically increased with warming, causing a massive upsurge in both wildlife & grazing production. Alice Springs has about 20,000 less people now than the MacDonnell Ranges sustained before whitefellas showed up.

Ibon & I are on exactly the same page on this. The tendency here, as with most discussion on the topic, is towards grand, sweeping visions of doom, which ignore natural reality, display geographic ignorance & disconnect from nature. In fact the picture is infinitely more complex & difficult to describe or predict.

Agreed, I watched the new Africa documentary series on Netflix earlier this month and the thing that surprised me most was the Atlas Mountains. They sit more or less smack dab in the Sahara surrounded by desert and judging by maps and geography lessons I always assumed they were pretty much low biodiversity desert climate. Turns out they are high enough that snow and rain fall on the peaks and upper slopes and they are covered in life, but you have to cross through very dry desert to get anywhere near them.

As for the Tropics, I studied up on Papua/New Guinea when I was doing my WW II history lessons. Westerners had always assumed they were low population mountains until WW II when aircraft started flying back and forth over them frequently from both the Japanese Army on the north coast and Australian/New Zealand/USA army on the south coast. Nobody could believe the entire cities worth of people living in the high mountain happily living on Taro root and Yam and dozens of tropical fruits and thousands of animals and even Sago palms harvested for starch.

In some places mountains are isolated and movement between them becomes very difficult if the lowlands are unbearable long term. Places like the Rocky mountains of North America, the Himalaya plateau and the Tropical Andes have supported relatively large populations of hunter gatherer's, herders and even in the Andes farmers with a large enough surplus to build an empire. The world is not a cue ball where everyone lives on the edge of the sea, but the media mostly does so that is the image they project. From Denver, Colorado it is almost a thousand miles going west before you fall below 3,000 meters in altitude. In tropical Africa Lake Victoria sits just south of the equator on a plateau at over 1,000 meters with many much higher mountains like Kilimanjaro scattered across the plateau.

As SeaGypsy pointed out himself relative humidity is pressure dependent, so the higher your altitude the easier it is for your body to reject heat through sweating. The controlling factor in ecosystems in these places is precipitation. The high mountains where it snows and rains have thriving life and relatively untouched ecosystems compared to the lowlands.

[vtsnowedin]

@ sg.....fair enough .....but how much land is there above 1000 metres?

thinking of my own back yard the land above 1000 metres is largely steep , generally rocky mountains.....infertile and difficult terrain

Steep and infertile is certainly true for much of the land above 1000 meters in elevation but there are exceptions. Consider Denver Colorado at 1600 meters and the great plains stretching east of it. And all the way North to Billings Montana at 1000 meters and going still further North to Fort McMurray Canada which is 370 meters high but presently only has a 90 day growing season.
For a little guidance I looked at a seed packet and the little map on the back that tells when it is safe to sow seeds outside. It has the continental US divided into four zones where what you can plant in March in Florida has to wait until June in Vermont. That Blue Zone includes eleven states and high altitude areas in a few more but is not fine enough to show the Sierra Nevada's or the spine of the Appalachians.

[SeaGypsy]

PNG is top of the list for significant populations in the tropics who would definitely survive both drastic climate change & economic collapse. About 5 million people still live very much off traditional agriculture. The oldest sustained farm in the world is fed from the only glacier in SE Asia, just over the 'border' of Irian Jaya, Indonesia, worked by a system of ponds & canoes moving stuff around. Over 2000 years feeding thousands of people, with zero imports.

I have often wished everyone had a human right to travel, to experience & gain from learning the pros & cons of various cultural & geographical positions. Unfortunately not only is it not going to happen, often even those most able to afford to really explore, just don't, don't want the risk, the confrontation, the conflict & contrast, & if they do travel they bring their bubble with them. These conversations remind me how it is when a bunch of seasoned travellers engage with a bunch of local yocals, anywhere in the world.

[SeaGypsy]

Tanada, that is one of the great attractions of the USA, the range of microclimates is extreme, from year round snow peaks to tropical islands, despite encroaching megalopolis, you still have a huge, beautiful & abundant country. I know it's trendy to talk the States down mostly around here, but from where I'm looking I can see great opportunity there.

[Ibon]

PNG is top of the list for significant populations in the tropics who would definitely survive both drastic climate change & economic collapse. About 5 million people still live very much off traditional agriculture. The oldest sustained farm in the world is fed from the only glacier in SE Asia, just over the 'border' of Irian Jaya, Indonesia, worked by a system of ponds & canoes moving stuff around. Over 2000 years feeding thousands of people, with zero imports.

I have often wished everyone had a human right to travel, to experience & gain from learning the pros & cons of various cultural & geographical positions. Unfortunately not only is it not going to happen, often even those most able to afford to really explore, just don't, don't want the risk, the confrontation, the conflict & contrast, & if they do travel they bring their bubble with them. These conversations remind me how it is when a bunch of seasoned travellers engage with a bunch of local yocals, anywhere in the world.

You could add the alto plano regions of southern Peru and Bolivia where high altitude farming remains in many areas unchanged since the days of the Incas. Potato harvests in these elevations are stratified with varieties that span different elevations. When you drop off the alto plano you quickly change vegetation zones as elevation quickly drops. Unlike the days of the Incas today there are food crops that have been introduced from all over the world so you can plant yucca, yams, plantains, beans, along with the existing quinoa and potato crops. Lower elevations for avocados, wheat, rice, mangos, citric, etc. I am just mentioning hi caloric crops here.

[SeaGypsy]

As I have mentioned Ibon, I have never lived over 1000 meters, 3 years in the Daintree, Atherton tableland, magical place. We had 3 meters rain a year & fantastic soil, year round brassicas, all the standard English & Mediterranean herbs, apples, pears, pecans citrus, avocado & banana. The money crop there was pumpkins, thriving year round with minimal care, I used them as my staple. This is 17 degrees from the equator, well inside the 'doomer dead zone' in continental Australia, likely to be a paradise for quite some time yet.

[Ibon]

This is an edited post from another thread that is relevant to the current theme being discussed here.

The geography of where I live in western Panama lies 9 degrees north of the equator in the tropics. Generous rainfall and fertile volcanic soils and an elevation gradient from sea level up to 3000 meters in the short distance of just 40 miles. On the coastal plains rice, sugar cane, cashews, bananas, papayas, pineapples, cassava and yucca are grown. Go up a little higher in just a few miles and you move into vast citrus groves and cacao and rambutans, mangosteens, guavas, sour sop, lowland pastures where Brahma cattle graze. Go a few more miles up and a micro climate of heavy rainfall is found where rising warm moist coastal air dumps rain almost year round. Here there is pasturage year round. Go a few more thousand feet up and you enter the elevation where temperate vegetables are grown; corn, potatoes, onions, tomatoes, lettuce, carrots, beets. And then toward the top at over 6000 feet you have coffee plantations and temperate varieties of cattle where dairy farms predominate. Again, this is all in a 40 mile distance. From that rice on the coastal plains all the way up to the high elevation dairy farms this is all considered local in term of transport if fossil fuels disappeared tomorrow. There is a plasticity present here with agriculture in this region where changes of climate can be accommodated by moving up and down altitudes.

Another point is that access to these higher elevations is limited to a few mountain valleys and a couple of roads These few roads would not be hard to maintain. Also controlling the flow of human traffic. Panama is actually not self sufficient in food production and most of the population is on the coastal capital of Panama City, 1.8 million people living in a humid and hot micro climate of concrete. If you get a heavy rain in the afternoons it cools things down in the city. If you get a small rain shower that is brief that falls on this hot concrete micro climate it acts like a steam sauna and this becomes truly unbearable. If conditions required an exodus of this city it would be quite devastating. The mountain culture in western Panama has a pioneer tradition that sees themselves as independent of Panama City They resent in fact the wealth that accumulates there and the fact that western panama, the province that feeds the city, does not receive a fair share of infrastructure investments. These provincial sentiments would become powerful if we would see climate change putting regional populations under stress.

[Newfie]

"A large population of hunter gatherers" is an extremely low population by today's standards. The kind of population you guys are describing are in the range of what most would consider extreme die off.

At first blush I have would also seem to make travel and commerce difficult. Assuming life on the ocean is still possible due to waters mitigating effects you have to get to the water in order to have trade. You also need large stands of large trees for ocean going craft.

I think the world you are describing is very post industrial, isolated outposts.

[Cid_Yama]

At 100% humidity, temperatures over 37 C are lethal after a very short time. That is when Apototic cell death begins to occur due to heat stress.

At 49-50 C anything over 10-15% humidity is lethal after a short time. At 55 C (131 F) necrotic cell death begins to occur, even with no humidity.

These limits are for individuals in perfect health, in their prime, at rest, in the shade, fully hydrated, in a breeze.

Since most of us do not fit those criteria, consider those to be the extreme limit and recognize other stressors will reduce your tolerance before apoptosis is initiated.

[onlooker]

Thanks Cid about this "At 100% humidity, temperatures over 37 C are lethal after a very short time. That is when Apototic cell death begins to occur due to heat stress". Even here in the NY State area we have come quite close to this the past few summers. I will be on the lookout for this lethal combination.

[Subjectivist]

At 100% humidity, temperatures over 37 C are lethal after a very short time. That is when Apototic cell death begins to occur due to heat stress.

At 49-50 C anything over 10-15% humidity is lethal after a short time. At 55 C (131 F) necrotic cell death begins to occur, even with no humidity.

These limits are for individuals in perfect health, in their prime, at rest, in the shade, fully hydrated, in a breeze.

Since most of us do not fit those criteria, consider those to be the extreme limit and recognize other stressors will reduce your tolerance before apoptosis is initiated.

Since even at the 12 C global warming theoretical max most of the globe won't get anywhere near 49 C temperatures what is your point exactly? That people in ovens will die?

The average summer high in Pheonix, AZ gets up to 42C every day for weeks. Yet it is considered a wonderful retirement location where a million senior citizens not in peak health continue to live. Add your max 12 C to Pheonix and it might be uninhabitable sure enough, but Detroit or Seattle or even NYC will not be. Wet bulb heat stress is extremely location dependent, why do you refuse to acknowledge that simple fact?

[Cid_Yama]

We are talking Temperature + humidity + level of activity + the ability to lose metabolic heat which can be hampered by age, illness, dehydration (a big one for most people), weather conditions, etc.

Average global temperature rise will not stop, people don't get that. CO2 and Water Vapor in the atmosphere will continue to rise. CO2 residence time will be on the order of a hundred thousand years. Methane residence time will increase as OH becomes depleted.

Central continental areas (where we grow most of our food) will experience much higher temperatures than the average. Surface sources of water will dry up, we have almost depleted the aquifers. In the United States our agricultural regions will become deserts.

Already this year India has hit 51 C.

Many of you either lack the basic knowledge to understand (which I have done my best to correct), or you don't want to hear, or can't hear due to defense mechanisms.

Sorry, that's your problem not mine.

This extinction event will continue until O2 levels in the atmosphere are low enough that we cannot survive, but I expect us to already be extinct due to other factors before then.

Atmospheric chemistry is already changing. Oceans are becoming more and more anoxic.

Do YOU think people can survive the conditions of the Early Triassic? Or even the PETM. That is where we are headed.

[Cid_Yama]

Let's take your example. As the atmosphere warms, it can hold more moisture. Which means humidity will rise to levels not currently experienced. At 42 C, humidity above 35% becomes lethal.

New York July average temp around 30 C, average humidity 70%.

Increase humidity to 80%, and increase temperatures by 4 C, New York is no longer habitable.

Just brief periods of lethality is enough.

[AgentR11]

Just a modest clarification.. For the same amount of moisture held in the air, the reported percentage humidity for higher temperature will be substantially lower.

So getting these ~35c with high humidity is very hard.

Eg, where I am, in the morning we are right at 100% humidity, at about 75F, but as it approaches 90F in the afternoon, humidity drops to around 60%; even though the air is actually holding MORE water.

This isn't to say WBT isn't a problem; but the difference between 30C/70% and 34C/80% is disproportionate to expectations in turns of amount of water and energy involved.

But yeah, brief periods where its potentially lethal to spend more than a few minutes outdoors will wreck the economy of the area and its dependents.

[vtsnowedin]

Let's take your example. As the atmosphere warms, it can hold more moisture. Which means humidity will rise to levels not currently experienced. At 42 C, humidity above 35% becomes lethal.

New York July average temp around 30 C, average humidity 70%.

Increase humidity to 80%, and increase temperatures by 4 C, New York is no longer habitable.

Just brief periods of lethality is enough.

It has happened before. The heat wave of 1896 killed 1500 and brought Teddy Roosevelt into the public eye.
http://www.npr.org/templates/story/stor ... =129127924

During the summer of 1896, a 10-day heat wave killed nearly 1,500 people, many of them tenement-dwellers, across New York City. Many thousands of people were crammed into tenements on the Lower East Side, with no air conditioning, little circulating air and no running water. Families were packed together — with five to six people sharing a single room. Extra space on the floor was rented out to single men — many of whom worked six days a week doing manual labor out in the sun.

"It was so densely packed that most people couldn't even live inside the tenement itself," says Ed Kohn, a professor of American history at Bilkent University in Ankara, Turkey. "The streets in front of tenements, and the rooftops and the fire escapes were ... filled with people all of the time because there was no room for everybody to fit inside."

Kohn is the author of Hot Time in the Old Town, which chronicles the fatal heat wave.
Hot Time in the Old Town: Cover Detail
Hot Time in the Old Town
By Edward P. Kohn
Hardcover, 304 pages
Basic Books
List price: $27.95
Read an Excerpt

"This was 10 days [with temperatures reaching] 90 degrees at street level and 90 percent humidity, with temperatures not even dropping at night," Kohn says. "No wind — so at night there was absolutely no relief whatsoever."

At the time, there was a citywide ban on sleeping in New York City's public parks. Kohn says one of the simplest things the city could have done was lift the ban — giving people a place to sleep away from their squalid tenements, which might have prevented many of the deaths.

"They took to the rooftops, and they took to the fire escapes, trying to catch a breath of fresh air," he says. "Inevitably, somebody would fall asleep or get drunk, roll off the top of a five-story tenement, crash into the courtyard below and be killed. You'd have children who would go to sleep on fire escapes and fall off and break their legs or be killed. People [tried] to go down to the piers on the East River and sleep there, out in the open — and would roll into the river and drown."

Until the very last days of the crisis, the city government did very little to help its poorest residents survive the heat wave. The mayor didn't call an emergency meeting of his department heads until the very last day — and even then, it was a little-known police commissioner named Theodore Roosevelt who championed the efforts to help New Yorkers survive the heat.

"[Roosevelt is] the one who champions the idea of the city giving away free ice to the poorest people living on the Lower East Side," Kohn explains. "And he personally supervises the distribution of ice. And after the ice was distributed, Roosevelt took it upon himself to tour the back alleys of some of the worst tenement districts in the United States to see how people were using the ice. So Roosevelt witnessed firsthand how immigrant fathers would chip off ice and give it to their children to suck on ... I can't think how many American presidents have had such intimate contact with the urban poor."
Ed Kohn
i

Ed Kohn teaches at Bilkent University in Ankara, Turkey.
Courtesy of the author

Kohn says the incident helped shape Roosevelt's progressive thinking and shaped his future life in political office — first as the governor of New York and later as the president of the United States.

"He was an urban reformer. His origins are in New York urban politics," Kohn says. "His roots ran deep into the soil of Manhattan, and for the rest of his life, he considered himself a New Yorker" — and went on to become a great champion of tenement reform.

[dohboi]

"The sub culture of doom warriors here browse the internet and copy and paste links and claim to be learned and objective. They sit down every day and search exactly those topics and studies..."

So on the one hand a group of posters (let's drop the nomenclature for now) who are constantly citing scientific studies, while on the other hand you have a group of posters that just state their biases, and make unsupported accusations to the other group of (ironically) confirmation bias, when they are not simply making unsupported 'arguments from incredulity.' http://rationalwiki.org/wiki/Argument_from_incredulity

I'm pretty sure that, in other contexts, since you are a pretty sharp fellow, you would say that it was the first group of posters who had the edge on the latter group (unless the latter group can come up with a broad set of studies that either disprove the those of the first group, or that come up with alternative findings).

I have, in fact, posted articles that go against a 'doomer' perspective, if you will. When there was good evidence that the Greenland Ice Sheet might be melting a little LESS quickly than thought, I posted that, iirc. I actually would love to find hundreds of articles that say everything is going to be fine, or that feedbacks are never likely to kick in, or that previous studies were too dire and it looks like things are much less bad than predicted.

But pretty much all I can find say the opposite.

If you can find a bunch of legitimate articles that that show that the icecaps aren't melting or that global temperatures aren't increasing or that past extinctions (which showed CO2 increases much slower than today's) didn't wipe out most life on the planet....

IF you can find a number of legit articles from legit sources like this, please, please post them.

I for one will be ecstatically delighted.

But if you can't, then you can't accuse us of selection bias or confirmations bias, you should apologize to us for falsely accusing us of the same, and you should...cease and desist.

Have a nice day!

(It should be pointed out that, in my case at least, I hardly represent the doomiest voice available, even among academics/scientists. Guy McPherson famously has said that total human extinction is inevitable within, what is it now, 16 years? I certainly don't make anything close to that claim.)