Apparently you missed it when 86 leading US evangelicals signed a statement calling for Christians to do more to combat global warming and environmental pollution. Or the Pope’s speech on the matter.
Victorsays
Has anyone here commented yet on this?
“Making Sense of the early 2000s warming slowdown”:
Jim Hunt @42.
And the RSS TLT posting I mention @38 shows the Arctic’s wacky 62N-82½N temperatures of January & February have dropped down from those record breaking levels. (Jan 2016 was +3.3ºC easily besting the previous outlier all-month record +2.6ºC of Jan 1981. Feb 2016 was +2.1ºC, a February record and 4th highest on the all-month record.) The March 2016 anomaly just posted isn’t even a record for March (only 2nd highest March anomaly, a lacklustre 0.041ºC below 1996) and a mere 17th on the all-month record.
As NSIDC’s Ted Scambos said (& as those scallywags known as the ‘Gentlemen Who Prefer Fantasy’ find his quote so objectionable it must bear repeating,)
“The Arctic is in crisis. Year by year, it’s slipping into a new state, and it’s hard to see how that won’t have an effect on weather throughout the Northern Hemisphere,”
Entropic mansays
45 zebra
Genetically you could get down to 10,000 people worldwide and come back. The low genetic diversity of humans suggests that such a population bottleneck has happened at least once before.
To maintain a civilisation you would need to maintain knowledge of each craft or speciality.I do not know how many crafts and specialities there are, but for safety you would need at least a master and two apprentices for each one to avoid any one death wiping out that skill.
Since developing a skill is a full time task you would also need enough food growers, hewers ofvwood and drawers of water to support all these specialists. I don’t know what the total would need to be, but if there are 10,000 skills you need 30,000 specialists and perhaps ten times as many to back them up
Hungry people in Philippines are being strafed, refugees streaming toward Germany from Syria etc. are getting the cold shoulder, and I read that the pakistani army has deployed low yield nuke weapons on the border with India. Not sure what a low yield nuke is? Maybe it’s not that different from the depleted uranium shells that the US employs in Iraq, Afghanistan etc.?
At some point, it seems like our species should stop wasting energy on armed conflict and put that energy toward dealing cooperatively with climate change, but maybe not. Some nation-states may choose continued conflict, unilateral geoengineering and wall-building etc to protect the status quo.
CO2 at 406 and change. I feel pretty good about that. Nothing to get alarmed about, but it’s good to keep in mind that the CO2 levels are not just about greenhouse effect, melting glaciers and polar ice-caps and sea level rise. According the Dawg scientists in Seattle we need to worry about ocean acidification as well. We probably have plenty of time to fix all this. I think for now we just need to keep signing online petitions and sending emails to our senators and representatives so that we can persuade Congress to come around a bit to the work that we may want to take on.
Richard Caldwellsays
zebra: Even if there is wide-spread mortality, knowledge will not vanish. In the long term, you only need enough individuals to maintain a diverse gene-pool–
Richard: Not even that. Diversity is only required IF the population has recessive flaws, such as Tay Sachs or sickle cell anemia, OR if the population will face an environmental situation that can only be solved genetically.
The average human carries 0.29 recessive genes that lead to sterility or death of 1/4 of the young if, and only if, that human mates with another with a similar genetic flaw. Those are way low odds. From a species survival standpoint, it’s irrelevant. Marrying your sister is NOT an issue. Even if you share ten times the normal fatal flaws, 42% of your kids will survive and be fertile, and ever larger percentages will survive in subsequent generations. With twelve kids, that’s seven potential successes. Add in an amazing 50% death rate above genetics, plus ignore the fact that male sterility can be bypassed, and the population still increases by over 50% each generation. That’s ten times AND identical. Statistically irrelevant.
Given that other species of large mammals will fare worse than ours, diseases will be largely eradicated in a world where nearly all humans perish. Add in vaccines and antibiotics, and genetic resistance to Ebola or whatnot really isn’t an issue. And other than disease, there aren’t any genetic limits to human survival.
So, as long as enough humans survive so that at least one fertile pair always survives and successfully finds each other and mates, humanity will squeak by.
But if you’re looking for something better, here’s one article estimating 150 to 10,000 folks arriving on a distant world would be enough to essentially ensure civilization’s continuity, barring some cataclysm.
More important than genetics is technology. There have to be enough folks to specialize in order for civilization as we know it to continue without a break. Currently, it takes teachers, doctors, mechanics, et al, but as robots take over the workforce, the number of humans required will plummet. So, it depends on how soon the bottleneck happens. In any case, genetically or specialization-wise, I can’t fathom needing more than the 10,000 folks suggested in the Popular Science article. That’s a 99.9999% death rate, give or take a zero. Obviously, barring a runaway greenhouse effect turning Earth into Venus2, we are not at risk of extinction, and our civilization will not go away even if we nuke the bejesus out of the planet. There simply aren’t enough Bombs.
Theosays
Re Pete @44: Yes, Kevin Anderson is probably (most likely) right. Like his style. He is like the old school friend you run into, who tells you how he finds it and how unfortunately it is that the world doesn’t quite get the predicament it is in. Trying hard, but a good solution seems hard to come by.
Michael Mann comes across like that as well.
Bit of a worry, but humanity has come this far
Theosays
Re Barton @50: But is this now part of the message being preached to the community ? If I was a god, I would be pretty disappointed, if my people were destroying this world I specially created for them.
And what plan should they suggest to implement with so many willing individual supporters ?
This is ‘long’, but I think addresses your questions.
Both of your posts are referring to ‘slow’ warming periods during the instrumental record. Victor – you linked a recent piece on the ‘hiatus’; one of the authors of that work (Fyfe) published this article a year ago, detailing what scientists believe is a main cause:
In short, the PDO/ENSO cycle (El Nino/La Nina) appears to have a fairly substantial effect on the global rate of warming. When we are in a predominantly El Nino phase, warming occurs rapidly; when we are in a predominantly La Nina phase, temperatures remain fairly level. And in the Nature article, they conclude that we should NOT be fooled by a predominant La Nina phase presenting a true ‘hiatus’, because when the PDO shifts back into an El Nino dominated phase for a few decades, warming will rapidly catch up with projections.
I’ve linked the woodfortrees site that others here are using, as it has nice online tools, and I can show you exactly what Fyfe and others are explaining (in somewhat less ‘sciency’ terms. Woodfortrees has tools for the ENSO and temperature which allow for the generation of nice graphs.
Here is a superposed temperature plot against the PDO phase:
I’m using GISTEMP data for the temperature record here; you can select others as well.
Note that I’ve scaled the PDO plot by 0.5 so the plots are easier to compare.
Now, if we break the PDO phases down, there are apparent ‘up/down’ phase shifts at:
1900-1920: mostly neutral, PDO is less than ±0.5 (or 0.25 on the scaled graph)
1920-1945: mostly “+ or El Nino”, PDO is greater than 0 and exceeds +0.5 during the run
1945-1978: mostly “- or La Nina”, PDO is less than 0 and drops below -0.5 during the run
1978-2006: mostly El Nino, and PDO exceeds 0.5 during the run
2006 on: mostly La Nina, so far, but too little data to infer much, but we have exceeded -0.5 during the short run so far
If you look at each of these major decadal changes in PDO, you can see how fast the Earth has warmed during each period.
Up to 1920:
We have almost no temperature trend during this 20 year period: maybe a -0.03°C over 20 years, so -0.015°C/decade
We have a small La Nina blurb at the tail end here, but not enough data to really decide if this is a phase inversion yet or not (or if a neutral break is starting).
Anyway, the temperature climb is about +0.5°C over 28 years, or about +0.18°C/decade
2006-present (2011): (Note that this ‘ends’ at 2011 due to the decadal averaging – the 2011 data point includes averaging data up to present, but is simply plotted at the 2011 midpoint of the decadal average)
Here, we only have 4.5 years of running average smoothing, and MAYBE a -0.01°C change in temperature, or -0.02°C/decade, but really could be flat at ‘0’ because the averaging time is too short to get a decent estimate.
Here is what the global temperature trends look like, by decadally averaged PDO phase ranges:
PDO and GISTEMP trends by PDO phase Timeframe PDO dT trend
1900-1920 ~Neutral -0.015 °C/decade 1920-1945 El Nino + 0.16 °C/decade
1945-1978 La Nina – 0.03 °C/decade 1978-2006 El Nino + 0.18 °C/decade
2006-2011* La Nina – -0.02 °C/decade
So, it’s not really any giant newsflash that we have warming during El Nino years and cooling during La Nina years, BUT look at the magnitudes we end up with:
•During any long El Nino dominated stretch, warming trends are about 2x the long-term average
•El Nino phases have nearly +0.2°C/decade warming trends
•La Nina phases have very small trends either way, but mostly neutral temperatures
What makes this interesting to me is that, during El Nino, warming is on steroids, but during La Nina we *do not* experience any cooling, only a ‘warming détente’ period.
Thus, IF we truly have a La Nina-dominated decade (or more, like the 3+ decades from the 40s to the 70s, WE WILL have a ‘warming hiatus’. But this ‘hiatus’ may ONLY be due to the PDO phase, and as we have seen historically, once we go back to 10 or 20 years of El Nino phases, the warming trends are going to go back to about 0.2°/decade (double the IPCC estimates of ‘overall’ warming, but if this warming is only going to occur in El Nino PDO years, we should be looking at the warming regression lines during those years.
Yes, we CAN have ‘hiatuses’, but based upon this information, they most certainly DO NOT disprove the warming, NOR to they discount the accuracy of the models, which cannot predict decadal shifts in PDO. If we assume PDO will be 50/50 El Nino/La Nina, the models are very likely correct over the long term.
Entropic mansays
#40 zebra
Genetically, world population could drop to 10,000 and bounce back without damage. Given the low genetic diversity of humanity, such population bottlenecks may already have happened.
If you want to maintain our knowledge and skills through such a bottleneck you would need at least one master and two apprentices for each speciality to avoid losing it all to on accidental death.
Such specialists need to devote their full time to their speciality. Each of them would need farmers, hewers of wood and drawers of water to support them.If that ratio is 9 supporters per specialist you can derive the equation
Minimum civilised population = number of specilities * 3 * 10
Looking great. Staying under the 405 number that Dr. Mann warned us about in 2014. And March was only third hottest march in the record, so we have already dropped two places from February, which was hottest feb on record.
I think all the folks here who tell the alarmists to relax are doing a great humanitarian service for us all.
It is true that we bumped up above 406 again on April 6, but that doesn’t really mean anything. We are clearly headed toward economic growth based on transition from fossil fuels. The market will sort all of this out for us:
55 Mike: DU is definitely not a nuclear weapon at all.
DU is what is left over from the enrichment process, the process that makes new reactor fuel. Spent fuel is reactor fuel that has been removed from a reactor because of the buildup of fission fragments. Fission fragments are atoms with an atomic number that averages about half of the atomic number of the fissionable fuel. Spent fuel is high level radioactive and must be handled only by robots. DU is safe to carry in your pocket and was available by mail order.
DU is used because DU is good for penetrating armor steel. A DU rod is self sharpening. Steel rod would “mushroom” and become very dull. Also, DU is denser than lead and DU is pyrophoric, meaning it starts fires.
By “low yield nuke” they mean something like the backpack nuke, which is small enough to carry in a backpack. The yield is adjustable to 2 kilotons, 1 kiloton, or 11 tons. It is clearly not DU because there is no possible way to make DU explode in a nuclear way.
A low yield nuke might be one that can be fired from a cannon.
zebrasays
In response to the several responses on post-apocalyptic scenarios:
The problem with a massive nuclear war is that it will destroy both knowledge and resources that would be used to help maintain a certain level of technology– that’s exactly what we target, after all. (I assume everyone knows that, although it doesn’t get discussed much any more.)
So realistically, however bad the food supply is getting, if it’s just starvation and conventional warfare, and perhaps some associated reduction in birthrate, and disease, there is plenty of time for “bunkering down” by the technologically sophisticated.
Zombies are not real, people! Invasions in the past have always been carried out by militarily adept populations, not starving refugees.
As for genetics; I wasn’t even thinking about pure survival, but rather a representative sample of what exists now, with all the variations and oddities that humans display. Redheads and math and music prodigies and so on.
So anyway, at the point you might get down to the 100’s of millions range, the population would sort itself into pools, like water after the rain, in environmentally sound areas. Heck, we’re already talking USA isolationism, right?
Edward Greischsays
55 Mike: DU is U238. Bombs require U235 or plutonium239. Other isotopes will not work.
Theosays
So to stop the worry about Arctic melt, they add Antarctica. Seeing their UAH temp article, I thought that they were laying low to avoid prosecution, but WattsUpInTheirHeads, this is plain stupidity. They at least admit that coal must have some bad effect, pushing that Hybrid coal plant solution.
Omega Centaurisays
Ed, You probably already know this, but DU can be fissioned by the high energy (fast) neutrons from a fusion reaction. High yield weapons are usually covered by a DU casing which greatly increases the yield as each fission releases several times energy of each fusion.
siddsays
Two interesting papers:
1)doi:10.1038/nature17418
“However, the intensification of the twentieth-century-mean hydroclimate anomalies in the simulations, as compared to previous centuries, is not supported by our new multi-proxy reconstruction”
Would someone care to hazard a guess as to why ?
[Response: Thanks Sidd. A number of us comment on this in this very good piece at Climate Brief. -Mike]
2)doi:10.1038/nature17174
8 Pg CO2 eq /yr soil sequestration may be possible (35 Pg Co2 is human fossil CO2 emission, disregarding the other noncondensing GHGs)
sidd
Chuck Hughessays
The process of getting from where we are to that point, however, involves all sorts of unpleasantries that may very well preclude your happy outcome.
I suggest looking up “Climate Wars” by Gwynne Dyer.
Comment by David Miller — 5 Apr 2016
“In response to the several responses on post-apocalyptic scenarios”……
Given all the “happy talk” I’ve been reading here on RC, I have to ask how many of you are expecting some sort of population crash on or before 2050?
I know Ed Greisch is expecting it but many others are talking like it’s inevitable. CO2 levels are holding steady at 406 and are certainly staying in the ‘well above 400ppm’ range and Merle Haggard just died. (Damn!)
Can anyone point to some recent credible assessments of where we might be right now in regards to a looming global crisis that will have an immediate effect on world population? I’ve been keeping up with Kevin Anderson’s posts and articles. He’s been pretty vocal about our situation. The other sources I check regularly have been relatively quiet other than the posts I’ve been reading here. For instance: Has Gwynne Dyer said anything recently, or Dr. Peter Ward et al?
Thanks
Thomassays
Hi Mike @ 56/62 – sorry I have no refs for this info, just sayin’ fwiw.
The most recent news out from the GBR scientists in Aus is about ongoing bleaching events, acidity, and crown of thorns starfish still. Apparently about 50% of the GBR is gone/damaged. Last week was a 90% (?) bleaching event in the top half, that’s along about 1000 klms.
Yesterday Sydney broke a 150 yr record going back to when records began at 34C. It was only ~10C above the mean avg. And of course there is a natural El Nino going on, so that must be part of it and no biggy. (?)
Many places on the east coast have been in the low 30s for weeks verus a 24-26 avg, and when it’s not unusual to very low 20C maximums this time of year in Sydney and further south. Overnight minimums have also set new records.
All this info is available from more reliable sources online if interested. I do suspect in about 3 years from now that John C Fyfe, Michael Mann et al will be updating their recent “Making Sense of the early 2000s warming slowdown” 15yr, 30yr, 50yr trends Paper again. [ and that is not a criticism of them in any way ]
[Response: Thanks Thomas, I think you’ll find our recent GRL article relevant to the matter :-) -Mike]
Joe P @60.
The one magic word you perhaps omit to mention with you reply to Victor (the troll) @51 is IPO. From Fyfe et al (2016)‘Making sense of the early-2000s warming slowdown’:-
A different perspective on the role of internal variability is obtained through the analysis of the individual models and realizations comprising the MME. In 10 out of 262 ensemble members, the simulations and observations had the same negative phase of the IPO during the slowdown period — that is, there was a fortuitous ‘lining up’ of internal decadal variability in the observed climate system and the 10 simulations. These 10 ensemble members captured the muted early-twenty-first-century warming, thus illustrating the role of internal variability in the slowdown.
And IPO ≈ PDO ≈ ENSO.
With regard to the 1950s-70s, (the subject raised by Adam R @20) Fyfe et al say “The IPO was another contributory factor to the big hiatus,” although the main culprit they finger is the anthropogenic sulphate aerosols.
Myself, I’m not sure that human aerosols & ENSO are the full explanation for that earlier wobble. But what does appear certain is that the earlier wobble cannot be subtracted from more recent temperatures as a sneaky way of reducing the size of AGW. Those that continue to perform such a trick are patently denialists.
I would thus take exception with Kevin McKinney @13 who describes Woy Spencer as a “lukewarmer”. No! He is a cold-hearted denialist who tells the world that it was all melty in the 1930s and again now, and which supports his argument that “the PDO might explain most of the climate change we’ve seen in the last 100 years or more.” If IPO ≈ PDO ≈ ENSO, we know http://iopscience.iop.org/article/10.1088/1748-9326/6/4/044022/meta;jsessionid=6249A168A60FDE4F923D3C7637098BC7.c2“>the impact of ENSO and so it is as plain as a pikestaff that the 1950s-70s wobble isn’t down to ENSO.
zebrasays
@Mike,
If your question about low-yield weapons was serious, read the Wikipedia article on “Davy Crockett”.
Maybe you can apply your sharp sense of humor to the idea of a bunch of those floating around Pakistan under the control of junior officers. What could go wrong?
The World Resources Institute, a climate think-tank based in Washington DC, has today released analysis showing which countries have achieved this decoupling, by comparing BP data on emissions to World Bank data on GDP.
But it’s not difficult to see that “Green Growth is a fantasy” because emissions cannot be reduced fast enough while maintaining economic growth.
LOW CARBON LIVING
Are there any settlements in the “developed world” where residents have carbon footprints that are anywhere near wht is necessary? In York we have a new “sustainable development” where footprints average 14.52 tonnes of CO2e – without even calculating the enormous embodied carbon in the bricks, cement &etc. If the world averaged this we would bust the remaining carbon budget for 1.5°C in two years. Are there better examples somewhere?
Oxfam has pointed out the richest 10% cause half the world’s carbon emissions. In “a world where 836m people still live in extreme poverty”, they must be helped by fining the affluent for their pollution (i.e. most people in Europe and the USA). Proceeds used to alleviate poverty and to help the world find better ways of living. An extension of Hansen’s Carbon Fee with Dividend to the whole world would be a good start.
#64 Zebra wrote a massive nuclear war is that it will destroy both knowledge and resources that would be used to help maintain a certain level of technology– that’s exactly what we target
We do not “target” it, but we approach a time when the usage or access in various parts of the world will become more of an option. In the current environment a full fledged nuclear confrontation between the US and Russia is not likely. But who knows it could change easily. But the problem is more with the amount and maintenance, and who has access, or a system could malfunction, or the use could be justified by the powers that be – because of some “incident”. There are many pathways for nuclears to make an impact. And nuclears might be even used because some people lost hope…
Zebra,
So it sounds like you are saying, “Extinction is for other species.” Why do you think humans are exempt?
I personally do not envision extinction as a likely near term (centuries) outcome. I do think collapse is a very real possibility if we increase our population to 10-12 billion and degrade Earth’s carrying capacity for humans to less than 100 million. That would not be an orderly process conducive to the maintenance of a technologically advanced global civilization. This is possible.
Climate-smart soils
Keith Paustian, Johannes Lehmann, Stephen Ogle, David Reay, G. Philip Robertson & Pete Smith
Nature 532, 49–57 (07 April 2016)
doi:10.1038/nature17174
Abstract:
Soils are integral to the function of all terrestrial ecosystems and to food and fibre production. An overlooked aspect of soils is their potential to mitigate greenhouse gas emissions. Although proven practices exist, the implementation of soil-based greenhouse gas mitigation activities are at an early stage and accurately quantifying emissions and reductions remains a substantial challenge. Emerging research and information technology developments provide the potential for a broader inclusion of soils in greenhouse gas policies. Here we highlight ‘state of the art’ soil greenhouse gas research, summarize mitigation practices and potentials, identify gaps in data and understanding and suggest ways to close such gaps through new research, technology and collaboration.
@Theo #66 – I presume you are referring to Willis’s recent HadISST “global sea ice” article at WUWT? That being the case, for additional info please see the archives at:
et seq. It probably won’t surprise you to learn that [Mod] and his [Snip]pers are ruthlessly suppressing dissenting voices. For more on that side of things see also the #SnipGate hashtag on Twitter.
zebrasays
@Ray Ladbury #76,
My original response was to the idea that we would “return to the Dark Ages” as the result of climate-driven disruption.
I didn’t suggest it would be fun to have the population reduced; of course it would be a horrific process. But that doesn’t change the fact that technology would be retained for those who survive.
There are (and have been) people starving and being slaughtered all over the world in fairly large numbers. If you were to increase that tenfold, people in the US would still be lining up to get the latest iPhone. Increase it by several orders of magnitude if you like. People here will still be worrying about their Facebook friend-ing or un- or whatever the latest thing is.
So yes, what counts as “global civilization” these days is pretty robust.
I’m not sure how you realistically get to 12 billion people and reduce carrying capacity below 100 millions, but… what if you did? I think that number would meet my criterion of a population that can accommodate diverse expression of the genome, and have electricity and flush toilets and antibiotics and so on.
Robin Johnsonsays
We [humans] are currently conducting an experiment designed to determine just how many people we can stuff on the planet – sustainable or not. There is still PLENTY of land in Africa, Russia and South America that could be made to produce food for another couple or three billion humans. The USA and Europe produce huge surpluses.
At some point, however, a food crisis will wrack ruin upon South Asia (From Egypt [technically Africa] to Indochina]. China’s population growth has slowed substantially and they have mopney to buy food at market rates. South Asia will not. The political unrest that results will unglue the already poorly governed region. And we may decide to let them starve.
So, we can pack a bunch more in the Americas and non-North Africa. I think South Asia is going to burst at the seams sooner rather than later. Depending on the timing of an implosion of South Asia – we might reach 9 or 10 billion humans easily.
zebrasays
@BPL #74,
“Hebrew infusion”
Is this going to be some joke involving seltzer?
Theosays
NSIDC heading: “March ends a most interesting winter” Nice way of putting it. And there was also a new word in there: coterminous ?
… While ODS [ozone depleting substance] levels remain high, a large stratospheric sulfuric aerosol enhancement due to a major volcanic eruption or geoengineering activities would result in a substantial chemical depletion of ozone over much of the globe. ”
boy, I listened to Dr. Mann per link at 79. It sounds like he is drinking the Hansen koolaid now. As cooler heads here told me last month when I was alarmed about the Feb record temp: dude, it’s one month in an ENSO year! Chill out.
I am chill now. Beautiful weather in the NW. A little warm today, in the 80s, but hey, I got my shirt off and enjoyed the sun.
I think Dr. Mann says on the video that the models have been underpredicting the actual rate and intensity of global warming. Wow, dude, get a grip. I have it on good authority that the models are solid, so this stuff will all smooth out. I read that there is some controversy about smoothing, pixel size etc. Not to worry, it gonna be fine.
I sorta locked on to Dr. Mann’s concern about 405 ppm from 2014 and that got my knickers in a knot, but now that I know that the CO2 ppm is not really the number to watch closely I feel great. My blood pressure is down, my cholesterol is looking great, I think I am even regrowing a little hair up on top where I thought global warming was starting to burn out my follicles. It’s all good. IEA numbers are the ones to watch, right? They are solid.
I glanced at the MLO numbers out of habit and read this:
Daily CO2
April 6, 2016: unavailable
April 6, 2015: 404.35 ppm
CO2 not even available. Those IEA fuel consumption reports have solved the problem.
I refuse to worry anymore. I just need to keep hearing from Ray, Hank, Mal and a few others that there is nothing to worry about and I am happy as a lobster in the aquarium at Red Lobster.
Also, elated to hear that DU is safe and not fissionable except under extreme circumstances. I was cleaning the garage and found some DU in box of weird stuff left by previous homeowner. Those folks were a little sketchy and I knew I would be cleaning up after them. Gotta stop and play with my grandson. He really loves the DU junk.
Maybe some of you folks can talk Dr. Mann down off the ledge. If a person sees something that alarms them, I figure holler WOW once and then relax. That covers it, right?
siddsays
Thanx for the link, Prof. Mann. The main disagreement seems to be in the bimodal distribution of NH hydro in the twentieth century in the model simulations but not in paleo reconstruction (Fig 3.) Bimodality is not clearly seen in previous centennial simulations or paleo reconstruction, so comparison of bimodal representation in previous centuries is difficult. We may have perhaps some insensitivity to bimodal anomaly in paleo, as indicated by better rain gauge agreement with modelling.
Has anyone tried this as a global comparison ? No millennium+ records in SH ?
Actually I don’t completely trust the Met Office now because they may be being softened up by this government for disposal to the private sector. Their sponsoring department is the Department of Business Information and Skills, who inherit much from the old Department of Trade and Industry (DTI). On the sale of a very expensive radar system to Tanzania Claire Short MP said in Parliament
The World Bank representative in east Africa was very concerned about the contract, as Tanzania was being considered for enhanced debt relief under the heavily indebted poor countries initiative…
The DTI sees it as its duty to push all arms sales deals and will always find arguments for them.
I suspect the Met Office is under pressure from BIS. Their scientists do meet with BIS officials.
Ex insiders will tell you the BBC was tamed years age. Even before they cancelled “Planet Relief” in 2007..
“It is absolutely not the BBC’s job to save the planet,” warned Newsnight editor Peter Barron at the Edinburgh Festival last month.
MSsays
It would be nice to have comments on this new study:
Observational constraints on mixed-phase clouds imply higher climate sensitivity
Abstract
Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.
I didn’t suggest it would be fun to have the population reduced; of course it would be a horrific process. But that doesn’t change the fact that technology would be retained for those who survive.
I’m not so sure. Modern civilization runs on logistics & globalized supply chains. Some feel that it’s robust to shocks of all sorts, but I don’t think that’s ever been tested, and probably not even examined very thoroughly. In fact, I don’t know that the system has ever been well described and characterized from that perspective–it keeps changing, for one thing, on time frames comparable to the length of big research projects, so my perception at least is that it would be pretty hard for researchers to ‘keep up.’
So I can’t help but wonder, in the event of serious disruptions to social structures, just how deep the destruction can go. Many of the ‘crucial resources’ tech runs on are manufactured–microchips, for one salient example. And last I heard there was considerable manufacturing capacity of the latter in some vulnerable areas, such as the South Asian region, mentioned by Robin in #83. Lose those resources, and specialist skills become irrelevant, almost instantly. Large chunks of the population could go from productive to economic liabilities very fast.
Essentially, I imagine a very sudden mismatch between skill sets and available resources. Highly competent people in huge numbers suddenly become neophytes, for practical economic purposes. Many of them probably die, but the mortality rate for their skills is even higher. The survivors are those whose skills match available resources better–which means what’s left of natural and manufactured resources.
Surely we’d have some McGyvers and Mark Watney types, who’d excel in ‘sciencing the shit out of’ such bad situations. And they’d have a strong survival edge, because they’d be valuable to whoever holds or achieves power in what is likely to be a chaotic social/political situation. But they might well be more scavengers than producers, technologically and scientifically. In short, I suspect it might get pretty damn bad in the worst case, easily justifying a ‘new Dark Ages’ label. I doubt it would be a carbon copy of the last time; probably some modern knowledge would persist at least in some places. (And the original Dark Ages did manage to produce innovations, too, a fact often overlooked–Asimov, for instance, wrote about the moldboard plow as one example. Gunpowder would be another.)
I don’t see this as inevitable by any means; I think we’re currently seeing departures from a pure BAU scenario, and I think that there will be acceleration of that trend. But I do think it’s possible.
Turning to Chuck’s question at #69–“Who expects a population crash by 2050?”–as being relevant here, I don’t ‘expect’ it, largely because I think we won’t realize the worst sort scenarios. I think that we’re going to see continuing decreases in carbon intensity on a global level which do a lot to mute the BAU emissions growth we would otherwise see. I think that we probably will not, however, do enough to avoid 2 C warming, and I think that we’ll see pretty drastic effects as a result. I think that those will include some very nasty high mortality events–hot spots could include South Asia, as Robin said, but IMO also Africa, where we have high population growth, low (but very uneven) economic development, strong climatic and ecological gradients, and in many cases persistently very poor governance.
I can only guess at gross population impact.
I very much doubt we’ll see anything of the kind by 2030 or 2035, but I’m not so sure about 2050. It may come down to the definition of ‘crash’. I don’t find a quantitative definition, but in the classic ecological studies we’ve talked about here previously, we’ve seen fast reductions by an order of magnitude or so–in other words, 90% mortality rates. I don’t think that’s likely for the global human population, at least on decadal timescales, because despite my point about globalization above, the geographic dispersion does still provide a significant buffer. But–should I live so long myself–I wouldn’t be shocked to find that cumulative first- and second-order climate change effects by 2050 prevent global population from ever reaching the 9 billion mark.
(The UPI story says the publication is in Nature, but that story’s “Nature” link opens this Science article)
__________________________________________
Observational constraints on mixed-phase clouds imply higher climate sensitivity
Ivy Tan1,*, Trude Storelvmo1, Mark D. Zelinka2
1Department of Geology and Geophysics, Yale University, New Haven, CT 06511, USA.
2Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
I don’t think we presently have a clue how to implement the Paris agreement technologically. Sure we have for two years running prevented fossil fuel usage from increasing even though globally the world economy has done so but as yet was it down to increased renewable deployments or other factors and is this a long term trend or just a blip?
The world uses 20% of its energy in electric form and 80% in other forms so wherever possible switching to electricity (Tesla Model 3 EV for example) could be a way of mitigating if the electricity is sourced from renewables.
Its a big tough situation and no certainties as yet.
Ray Ladburysays
Zebra,
So if transport breaks down, you’ll be able to grow sufficient food for you and your family to make it through Winter? And when your computer breaks down, you’ll be able to build new electronics in 22-nm feature size CMOS? And you know where to get potable water and how to treat it? And you’ll know what to do when one of your children gets severe diarrhea and becomes seriously dehydrated?
The problem is that our technological society is highly specialized, and it is unclear how robust it is, given that specialization. Don’t count on the rich world being able to raise the drawbridge and watch while the vast majority of people die. Many of the most vulnerable live in areas that are quite technologically advanced, and they are quite capable of cyber attacks if they feel abandoned. So don’t count on being able to G**gle how to survive.
Will civilization collapse if we have a very disorderly population collapse? I don’t know. However, I am far less sanguine than you that anything resembling an advanced technological global civilization will exist 200 years from now.
… new research … suggests climate models have overestimated how much ice is in clouds, meaning less is available to be converted to liquid as temperatures rise.
“When carbon dioxide concentrations and temperatures rise, then mixed-phase clouds will increase their liquid water content,” said Ivy Tan, a PhD candidate at Yale University who led the research, which investigated common clouds that contain both ice and water. “Many models are overestimating how much ice is in the mixed-phase clouds.”
I have it on good authority that there is nothing wrong with the climate models. I heard it right here last month when I opined that the models might need some work. Can some of you folks here in the comment community send a quick message to Ivy Tan and straighten this out please?
Beautiful day in the NW, going to hit 79 and I am taking grandkids to the park to play. I was worried about the world we were leaving them, but since I was told that global warming is not going to be a big problem until 2100 I have relaxed. Neither me or the grandkids are likely to live that long. No worries!
CO2 bounced back today for those of you are still worried about that number:
Daily CO2
April 7, 2016: 407.74 ppm
April 7, 2015: 404.65 ppm
407.74 seems like a big number, but so what? It’s only 3ppm over last year this time and it’s an El Nino year. It’s going to drop like a rock thanks to the IEA reports of fossil fuel burning. That is the number we need to be watching now, right?
I do think it’s time to stop the end times talk and get back to climate talk. Things are looking rosy for us all, are they not?
Warm regards
Mike
S.B. Ripmansays
From an article just out in the NYT, regarding a new paper by Amy Tan et. al.:
“The computer models that predict climate change may be overestimating the cooling power of clouds, new research suggests. If the findings are borne out by further research, it suggests that making progress against global warming will be even harder.
“The new paper, in the journal Science, focuses on what are known as mixed-phase clouds, which are found around the world and contain both cooled water and ice crystals.
…
“The new paper suggests the effects of a flaw in the model could be serious: Based on its analysis of one model of climate change, the cloud error could mean an additional 1.3 degrees Celsius of warming than expected.”
According to a Wikipedia article on Richard Lindzen, “ … he … believes that decreasing tropical cirrus clouds in a warmer world will allow more longwave radiation to escape the atmosphere, counteracting the warming.”
Is this new paper by Tan et. al. another nail in the coffin for the theories of Prof. Lindzen?
Is the “additional 1.3 degrees Celsius” as bad as it sounds?
[Response: I think the press on this paper was pretty bad, and while it’s interesting work, it doesn’t have the implications that have been described (see this set of tweets for some more). I’ll see if I can’t write more about it this weekend. – gavin]
Some folks are reading this and thinking that our species is headed for a population crash. Complete drivel. Do they have any idea how many of us are here? Have they factored in that we will fight anything that looks like a population crash?
Going for a walk, beautiful day, maybe a trifle warm.
Barton Paul Levenson says
Theo @43,
Apparently you missed it when 86 leading US evangelicals signed a statement calling for Christians to do more to combat global warming and environmental pollution. Or the Pope’s speech on the matter.
Victor says
Has anyone here commented yet on this?
“Making Sense of the early 2000s warming slowdown”:
http://www.nature.com/articles/nclimate2938.epdf?referrer_access_token=rO_LAj7Squh3f_qt6natqdRgN0jAjWel9jnR3ZoTv0OqExA1EwYluYLwiaayT9ble9FcNagQ1ss5L1V0KiWd-xzbFQjp8p3e-nUsgU7jNuUykRRWZpgMltUfROWf3xSKeGSSY7TvMiWdaeBCmNzlbQKCodQ3ivWje8eZYAs8Dr1uu8L-i3CHt8f_jYiil5eUpRpdxdWDCSCvqts_NYB_l8yUG-b6Qu0dtrZLMnaUyec%3D&tracking_referrer=www.nature.com
David Miller says
#45 Zebra, I agree that the population of Germany could maintain itself if there were no other human inhabitants to compete with.
The process of getting from where we are to that point, however, involves all sorts of unpleasantries that may very well preclude your happy outcome.
I suggest looking up “Climate Wars” by Gwynne Dyer.
MA Rodger says
Jim Hunt @42.
And the RSS TLT posting I mention @38 shows the Arctic’s wacky 62N-82½N temperatures of January & February have dropped down from those record breaking levels. (Jan 2016 was +3.3ºC easily besting the previous outlier all-month record +2.6ºC of Jan 1981. Feb 2016 was +2.1ºC, a February record and 4th highest on the all-month record.) The March 2016 anomaly just posted isn’t even a record for March (only 2nd highest March anomaly, a lacklustre 0.041ºC below 1996) and a mere 17th on the all-month record.
As NSIDC’s Ted Scambos said (& as those scallywags known as the ‘Gentlemen Who Prefer Fantasy’ find his quote so objectionable it must bear repeating,)
Entropic man says
45 zebra
Genetically you could get down to 10,000 people worldwide and come back. The low genetic diversity of humans suggests that such a population bottleneck has happened at least once before.
To maintain a civilisation you would need to maintain knowledge of each craft or speciality.I do not know how many crafts and specialities there are, but for safety you would need at least a master and two apprentices for each one to avoid any one death wiping out that skill.
Since developing a skill is a full time task you would also need enough food growers, hewers ofvwood and drawers of water to support all these specialists. I don’t know what the total would need to be, but if there are 10,000 skills you need 30,000 specialists and perhaps ten times as many to back them up
330,000?
Mike says
Scientists at UW seem worried about ocean acidification and how it may be a particularly serious problem on the NW coast.
http://westcoastoah.org/product-release/
Daily CO2
April 4, 2016: 406.09 ppm
April 4, 2015: 402.45 ppm
Hungry people in Philippines are being strafed, refugees streaming toward Germany from Syria etc. are getting the cold shoulder, and I read that the pakistani army has deployed low yield nuke weapons on the border with India. Not sure what a low yield nuke is? Maybe it’s not that different from the depleted uranium shells that the US employs in Iraq, Afghanistan etc.?
At some point, it seems like our species should stop wasting energy on armed conflict and put that energy toward dealing cooperatively with climate change, but maybe not. Some nation-states may choose continued conflict, unilateral geoengineering and wall-building etc to protect the status quo.
CO2 at 406 and change. I feel pretty good about that. Nothing to get alarmed about, but it’s good to keep in mind that the CO2 levels are not just about greenhouse effect, melting glaciers and polar ice-caps and sea level rise. According the Dawg scientists in Seattle we need to worry about ocean acidification as well. We probably have plenty of time to fix all this. I think for now we just need to keep signing online petitions and sending emails to our senators and representatives so that we can persuade Congress to come around a bit to the work that we may want to take on.
Richard Caldwell says
zebra: Even if there is wide-spread mortality, knowledge will not vanish. In the long term, you only need enough individuals to maintain a diverse gene-pool–
Richard: Not even that. Diversity is only required IF the population has recessive flaws, such as Tay Sachs or sickle cell anemia, OR if the population will face an environmental situation that can only be solved genetically.
The average human carries 0.29 recessive genes that lead to sterility or death of 1/4 of the young if, and only if, that human mates with another with a similar genetic flaw. Those are way low odds. From a species survival standpoint, it’s irrelevant. Marrying your sister is NOT an issue. Even if you share ten times the normal fatal flaws, 42% of your kids will survive and be fertile, and ever larger percentages will survive in subsequent generations. With twelve kids, that’s seven potential successes. Add in an amazing 50% death rate above genetics, plus ignore the fact that male sterility can be bypassed, and the population still increases by over 50% each generation. That’s ten times AND identical. Statistically irrelevant.
http://www.genetics.org/content/199/4/1243
Given that other species of large mammals will fare worse than ours, diseases will be largely eradicated in a world where nearly all humans perish. Add in vaccines and antibiotics, and genetic resistance to Ebola or whatnot really isn’t an issue. And other than disease, there aren’t any genetic limits to human survival.
So, as long as enough humans survive so that at least one fertile pair always survives and successfully finds each other and mates, humanity will squeak by.
But if you’re looking for something better, here’s one article estimating 150 to 10,000 folks arriving on a distant world would be enough to essentially ensure civilization’s continuity, barring some cataclysm.
http://www.popularmechanics.com/space/deep-space/a10369/how-many-people-does-it-take-to-colonize-another-star-system-16654747/
More important than genetics is technology. There have to be enough folks to specialize in order for civilization as we know it to continue without a break. Currently, it takes teachers, doctors, mechanics, et al, but as robots take over the workforce, the number of humans required will plummet. So, it depends on how soon the bottleneck happens. In any case, genetically or specialization-wise, I can’t fathom needing more than the 10,000 folks suggested in the Popular Science article. That’s a 99.9999% death rate, give or take a zero. Obviously, barring a runaway greenhouse effect turning Earth into Venus2, we are not at risk of extinction, and our civilization will not go away even if we nuke the bejesus out of the planet. There simply aren’t enough Bombs.
Theo says
Re Pete @44: Yes, Kevin Anderson is probably (most likely) right. Like his style. He is like the old school friend you run into, who tells you how he finds it and how unfortunately it is that the world doesn’t quite get the predicament it is in. Trying hard, but a good solution seems hard to come by.
Michael Mann comes across like that as well.
Bit of a worry, but humanity has come this far
Theo says
Re Barton @50: But is this now part of the message being preached to the community ? If I was a god, I would be pretty disappointed, if my people were destroying this world I specially created for them.
And what plan should they suggest to implement with so many willing individual supporters ?
Joe P says
#20: @ Adam R
and
#51: @ Victor
This is ‘long’, but I think addresses your questions.
Both of your posts are referring to ‘slow’ warming periods during the instrumental record. Victor – you linked a recent piece on the ‘hiatus’; one of the authors of that work (Fyfe) published this article a year ago, detailing what scientists believe is a main cause:
http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2605.html
In short, the PDO/ENSO cycle (El Nino/La Nina) appears to have a fairly substantial effect on the global rate of warming. When we are in a predominantly El Nino phase, warming occurs rapidly; when we are in a predominantly La Nina phase, temperatures remain fairly level. And in the Nature article, they conclude that we should NOT be fooled by a predominant La Nina phase presenting a true ‘hiatus’, because when the PDO shifts back into an El Nino dominated phase for a few decades, warming will rapidly catch up with projections.
I’ve linked the woodfortrees site that others here are using, as it has nice online tools, and I can show you exactly what Fyfe and others are explaining (in somewhat less ‘sciency’ terms. Woodfortrees has tools for the ENSO and temperature which allow for the generation of nice graphs.
Here is a superposed temperature plot against the PDO phase:
I’m using GISTEMP data for the temperature record here; you can select others as well.
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:1900/scale:0.5/plot/noise/scale:0.0001/from:1900/plot/gistemp/mean:29/mean:39/mean:51/from:1900
Note that I’ve scaled the PDO plot by 0.5 so the plots are easier to compare.
Now, if we break the PDO phases down, there are apparent ‘up/down’ phase shifts at:
1900-1920: mostly neutral, PDO is less than ±0.5 (or 0.25 on the scaled graph)
1920-1945: mostly “+ or El Nino”, PDO is greater than 0 and exceeds +0.5 during the run
1945-1978: mostly “- or La Nina”, PDO is less than 0 and drops below -0.5 during the run
1978-2006: mostly El Nino, and PDO exceeds 0.5 during the run
2006 on: mostly La Nina, so far, but too little data to infer much, but we have exceeded -0.5 during the short run so far
If you look at each of these major decadal changes in PDO, you can see how fast the Earth has warmed during each period.
Up to 1920:
We have almost no temperature trend during this 20 year period: maybe a -0.03°C over 20 years, so -0.015°C/decade
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:1900/to:1920/scale:0.5/plot/noise/scale:0.0001/from:1900/to:1920/plot/gistemp/mean:29/mean:39/mean:51/from:1900/to:1920/plot/gistemp/mean:29/mean:39/mean:51/from:1900/to:1920/trend
1920-1945:
During the mostly “+” PDO phase, we have a significant and rapid temperature increase: almost 0.4°C in 25 years, so about +0.16°C/decade
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:1920/to:1945/scale:0.5/plot/noise/scale:0.0001/from:1920/to:1945/plot/gistemp/mean:29/mean:39/mean:51/from:1920/to:1945/plot/gistemp/mean:29/mean:39/mean:51/from:1920/to:1945/trend
1945-1978:
Mostly “-“ La Nina phase; about 0.1°C rise over 33 years, or about +0.03°C/decade
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:1945/to:1978/scale:0.5/plot/noise/scale:0.0001/from:1945/to:1978/plot/gistemp/mean:29/mean:39/mean:51/from:1945/to:1978/plot/gistemp/mean:29/mean:39/mean:51/from:1945/to:1978/trend
1978-2006:
We have a small La Nina blurb at the tail end here, but not enough data to really decide if this is a phase inversion yet or not (or if a neutral break is starting).
Anyway, the temperature climb is about +0.5°C over 28 years, or about +0.18°C/decade
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:1978/to:2006/scale:0.5/plot/noise/scale:0.0001/from:1978/to:2006/plot/gistemp/mean:29/mean:39/mean:51/from:1978/to:2006/plot/gistemp/mean:29/mean:39/mean:51/from:1978/to:2006/trend
2006-present (2011): (Note that this ‘ends’ at 2011 due to the decadal averaging – the 2011 data point includes averaging data up to present, but is simply plotted at the 2011 midpoint of the decadal average)
Here, we only have 4.5 years of running average smoothing, and MAYBE a -0.01°C change in temperature, or -0.02°C/decade, but really could be flat at ‘0’ because the averaging time is too short to get a decent estimate.
http://www.woodfortrees.org/graph/jisao-pdo/mean:29/mean:39/mean:51/from:2006/to:2015/scale:0.5/plot/noise/scale:0.0001/from:2006/to:2015/plot/gistemp/mean:29/mean:39/mean:51/from:2006/to:2015/plot/gistemp/mean:29/mean:39/mean:51/from:2006/to:2015/trend
Here is what the global temperature trends look like, by decadally averaged PDO phase ranges:
PDO and GISTEMP trends by PDO phase
Timeframe PDO dT trend
1900-1920 ~Neutral -0.015 °C/decade
1920-1945 El Nino + 0.16 °C/decade
1945-1978 La Nina – 0.03 °C/decade
1978-2006 El Nino + 0.18 °C/decade
2006-2011* La Nina – -0.02 °C/decade
So, it’s not really any giant newsflash that we have warming during El Nino years and cooling during La Nina years, BUT look at the magnitudes we end up with:
•During any long El Nino dominated stretch, warming trends are about 2x the long-term average
•El Nino phases have nearly +0.2°C/decade warming trends
•La Nina phases have very small trends either way, but mostly neutral temperatures
What makes this interesting to me is that, during El Nino, warming is on steroids, but during La Nina we *do not* experience any cooling, only a ‘warming détente’ period.
Thus, IF we truly have a La Nina-dominated decade (or more, like the 3+ decades from the 40s to the 70s, WE WILL have a ‘warming hiatus’. But this ‘hiatus’ may ONLY be due to the PDO phase, and as we have seen historically, once we go back to 10 or 20 years of El Nino phases, the warming trends are going to go back to about 0.2°/decade (double the IPCC estimates of ‘overall’ warming, but if this warming is only going to occur in El Nino PDO years, we should be looking at the warming regression lines during those years.
Yes, we CAN have ‘hiatuses’, but based upon this information, they most certainly DO NOT disprove the warming, NOR to they discount the accuracy of the models, which cannot predict decadal shifts in PDO. If we assume PDO will be 50/50 El Nino/La Nina, the models are very likely correct over the long term.
Entropic man says
#40 zebra
Genetically, world population could drop to 10,000 and bounce back without damage. Given the low genetic diversity of humanity, such population bottlenecks may already have happened.
If you want to maintain our knowledge and skills through such a bottleneck you would need at least one master and two apprentices for each speciality to avoid losing it all to on accidental death.
Such specialists need to devote their full time to their speciality. Each of them would need farmers, hewers of wood and drawers of water to support them.If that ratio is 9 supporters per specialist you can derive the equation
Minimum civilised population = number of specilities * 3 * 10
Now; how many specialities are there?
mike says
Daily CO2
April 5, 2016: 406.45 ppm
April 5, 2015: 403.64 ppm
March CO2
March 2016: 404.83 ppm
March 2015: 401.52 ppm
Looking great. Staying under the 405 number that Dr. Mann warned us about in 2014. And March was only third hottest march in the record, so we have already dropped two places from February, which was hottest feb on record.
I think all the folks here who tell the alarmists to relax are doing a great humanitarian service for us all.
It is true that we bumped up above 406 again on April 6, but that doesn’t really mean anything. We are clearly headed toward economic growth based on transition from fossil fuels. The market will sort all of this out for us:
http://www.carbonbrief.org/the-35-countries-cutting-the-link-between-economic-growth-and-emissions
Edward Greisch says
55 Mike: DU is definitely not a nuclear weapon at all.
DU is what is left over from the enrichment process, the process that makes new reactor fuel. Spent fuel is reactor fuel that has been removed from a reactor because of the buildup of fission fragments. Fission fragments are atoms with an atomic number that averages about half of the atomic number of the fissionable fuel. Spent fuel is high level radioactive and must be handled only by robots. DU is safe to carry in your pocket and was available by mail order.
DU is used because DU is good for penetrating armor steel. A DU rod is self sharpening. Steel rod would “mushroom” and become very dull. Also, DU is denser than lead and DU is pyrophoric, meaning it starts fires.
By “low yield nuke” they mean something like the backpack nuke, which is small enough to carry in a backpack. The yield is adjustable to 2 kilotons, 1 kiloton, or 11 tons. It is clearly not DU because there is no possible way to make DU explode in a nuclear way.
A low yield nuke might be one that can be fired from a cannon.
zebra says
In response to the several responses on post-apocalyptic scenarios:
The problem with a massive nuclear war is that it will destroy both knowledge and resources that would be used to help maintain a certain level of technology– that’s exactly what we target, after all. (I assume everyone knows that, although it doesn’t get discussed much any more.)
So realistically, however bad the food supply is getting, if it’s just starvation and conventional warfare, and perhaps some associated reduction in birthrate, and disease, there is plenty of time for “bunkering down” by the technologically sophisticated.
Zombies are not real, people! Invasions in the past have always been carried out by militarily adept populations, not starving refugees.
As for genetics; I wasn’t even thinking about pure survival, but rather a representative sample of what exists now, with all the variations and oddities that humans display. Redheads and math and music prodigies and so on.
So anyway, at the point you might get down to the 100’s of millions range, the population would sort itself into pools, like water after the rain, in environmentally sound areas. Heck, we’re already talking USA isolationism, right?
Edward Greisch says
55 Mike: DU is U238. Bombs require U235 or plutonium239. Other isotopes will not work.
Theo says
So to stop the worry about Arctic melt, they add Antarctica. Seeing their UAH temp article, I thought that they were laying low to avoid prosecution, but WattsUpInTheirHeads, this is plain stupidity. They at least admit that coal must have some bad effect, pushing that Hybrid coal plant solution.
Omega Centauri says
Ed, You probably already know this, but DU can be fissioned by the high energy (fast) neutrons from a fusion reaction. High yield weapons are usually covered by a DU casing which greatly increases the yield as each fission releases several times energy of each fusion.
sidd says
Two interesting papers:
1)doi:10.1038/nature17418
“However, the intensification of the twentieth-century-mean hydroclimate anomalies in the simulations, as compared to previous centuries, is not supported by our new multi-proxy reconstruction”
Would someone care to hazard a guess as to why ?
[Response: Thanks Sidd. A number of us comment on this in this very good piece at Climate Brief. -Mike]
2)doi:10.1038/nature17174
8 Pg CO2 eq /yr soil sequestration may be possible (35 Pg Co2 is human fossil CO2 emission, disregarding the other noncondensing GHGs)
sidd
Chuck Hughes says
The process of getting from where we are to that point, however, involves all sorts of unpleasantries that may very well preclude your happy outcome.
I suggest looking up “Climate Wars” by Gwynne Dyer.
Comment by David Miller — 5 Apr 2016
“In response to the several responses on post-apocalyptic scenarios”……
Given all the “happy talk” I’ve been reading here on RC, I have to ask how many of you are expecting some sort of population crash on or before 2050?
I know Ed Greisch is expecting it but many others are talking like it’s inevitable. CO2 levels are holding steady at 406 and are certainly staying in the ‘well above 400ppm’ range and Merle Haggard just died. (Damn!)
Can anyone point to some recent credible assessments of where we might be right now in regards to a looming global crisis that will have an immediate effect on world population? I’ve been keeping up with Kevin Anderson’s posts and articles. He’s been pretty vocal about our situation. The other sources I check regularly have been relatively quiet other than the posts I’ve been reading here. For instance: Has Gwynne Dyer said anything recently, or Dr. Peter Ward et al?
Thanks
Thomas says
Hi Mike @ 56/62 – sorry I have no refs for this info, just sayin’ fwiw.
The most recent news out from the GBR scientists in Aus is about ongoing bleaching events, acidity, and crown of thorns starfish still. Apparently about 50% of the GBR is gone/damaged. Last week was a 90% (?) bleaching event in the top half, that’s along about 1000 klms.
Yesterday Sydney broke a 150 yr record going back to when records began at 34C. It was only ~10C above the mean avg. And of course there is a natural El Nino going on, so that must be part of it and no biggy. (?)
Many places on the east coast have been in the low 30s for weeks verus a 24-26 avg, and when it’s not unusual to very low 20C maximums this time of year in Sydney and further south. Overnight minimums have also set new records.
All this info is available from more reliable sources online if interested. I do suspect in about 3 years from now that John C Fyfe, Michael Mann et al will be updating their recent “Making Sense of the early 2000s warming slowdown” 15yr, 30yr, 50yr trends Paper again. [ and that is not a criticism of them in any way ]
[Response: Thanks Thomas, I think you’ll find our recent GRL article relevant to the matter :-) -Mike]
MA Rodger says
Joe P @60.
The one magic word you perhaps omit to mention with you reply to Victor (the troll) @51 is IPO. From Fyfe et al (2016)‘Making sense of the early-2000s warming slowdown’:-
And IPO ≈ PDO ≈ ENSO.
With regard to the 1950s-70s, (the subject raised by Adam R @20) Fyfe et al say “The IPO was another contributory factor to the big hiatus,” although the main culprit they finger is the anthropogenic sulphate aerosols.
Myself, I’m not sure that human aerosols & ENSO are the full explanation for that earlier wobble. But what does appear certain is that the earlier wobble cannot be subtracted from more recent temperatures as a sneaky way of reducing the size of AGW. Those that continue to perform such a trick are patently denialists.
I would thus take exception with Kevin McKinney @13 who describes Woy Spencer as a “lukewarmer”. No! He is a cold-hearted denialist who tells the world that it was all melty in the 1930s and again now, and which supports his argument that “the PDO might explain most of the climate change we’ve seen in the last 100 years or more.” If IPO ≈ PDO ≈ ENSO, we know http://iopscience.iop.org/article/10.1088/1748-9326/6/4/044022/meta;jsessionid=6249A168A60FDE4F923D3C7637098BC7.c2“>the impact of ENSO and so it is as plain as a pikestaff that the 1950s-70s wobble isn’t down to ENSO.
zebra says
@Mike,
If your question about low-yield weapons was serious, read the Wikipedia article on “Davy Crockett”.
Maybe you can apply your sharp sense of humor to the idea of a bunch of those floating around Pakistan under the control of junior officers. What could go wrong?
Geoff Beacon says
GREEN GROWTH
Carbon Brief has asked “Is it possible to reduce emissions while growing the economy?” They report
But it’s not difficult to see that “Green Growth is a fantasy” because emissions cannot be reduced fast enough while maintaining economic growth.
LOW CARBON LIVING
Are there any settlements in the “developed world” where residents have carbon footprints that are anywhere near wht is necessary? In York we have a new “sustainable development” where footprints average 14.52 tonnes of CO2e – without even calculating the enormous embodied carbon in the bricks, cement &etc. If the world averaged this we would bust the remaining carbon budget for 1.5°C in two years. Are there better examples somewhere?
Oxfam has pointed out the richest 10% cause half the world’s carbon emissions. In “a world where 836m people still live in extreme poverty”, they must be helped by fining the affluent for their pollution (i.e. most people in Europe and the USA). Proceeds used to alleviate poverty and to help the world find better ways of living. An extension of Hansen’s Carbon Fee with Dividend to the whole world would be a good start.
Barton Paul Levenson says
zebra @60: Invasions in the past have always been carried out by militarily adept populations, not starving refugees.
BPL: It strikes me that the Hebrew infusion into the middle east is a counterexample.
Chris Machens says
The next layer of climate denial, blocking of critical climate science (What is fair use or tolerance of a taxpayers funded entity?)
How the BBC fights science and supports climate denial
http://climatestate.com/2016/04/07/how-the-bbc-fights-science-and-supports-climate-denial/
Chris Machens says
#64 Zebra wrote a massive nuclear war is that it will destroy both knowledge and resources that would be used to help maintain a certain level of technology– that’s exactly what we target
We do not “target” it, but we approach a time when the usage or access in various parts of the world will become more of an option. In the current environment a full fledged nuclear confrontation between the US and Russia is not likely. But who knows it could change easily. But the problem is more with the amount and maintenance, and who has access, or a system could malfunction, or the use could be justified by the powers that be – because of some “incident”. There are many pathways for nuclears to make an impact. And nuclears might be even used because some people lost hope…
If you are in the mood watch “Nuclear Winter – Alan Robock on Reality Asserts Itself” https://www.youtube.com/watch?v=-clx85iTvrE
Chris Machens says
And the last part: What to Do Next About Global Warming? – Alan Robock on Reality Asserts Itself https://www.youtube.com/watch?v=wlsubQ0-8IE
Spot on
Ray Ladbury says
Zebra,
So it sounds like you are saying, “Extinction is for other species.” Why do you think humans are exempt?
I personally do not envision extinction as a likely near term (centuries) outcome. I do think collapse is a very real possibility if we increase our population to 10-12 billion and degrade Earth’s carrying capacity for humans to less than 100 million. That would not be an orderly process conducive to the maintenance of a technologically advanced global civilization. This is possible.
Chris Machens says
Dr. Michael Mann – Are We In Runaway Climate Change? http://climatestate.com/2016/04/07/dr-michael-mann-are-we-in-runaway-climate-change/
SecularAnimist says
FYI:
Climate-smart soils
Keith Paustian, Johannes Lehmann, Stephen Ogle, David Reay, G. Philip Robertson & Pete Smith
Nature 532, 49–57 (07 April 2016)
doi:10.1038/nature17174
Abstract:
Jim Hunt says
@Theo #66 – I presume you are referring to Willis’s recent HadISST “global sea ice” article at WUWT? That being the case, for additional info please see the archives at:
http://GreatWhiteCon.info/2016/03/hadisst-historical-arctic-sea-ice-data/#comment-214139
et seq. It probably won’t surprise you to learn that [Mod] and his [Snip]pers are ruthlessly suppressing dissenting voices. For more on that side of things see also the #SnipGate hashtag on Twitter.
zebra says
@Ray Ladbury #76,
My original response was to the idea that we would “return to the Dark Ages” as the result of climate-driven disruption.
I didn’t suggest it would be fun to have the population reduced; of course it would be a horrific process. But that doesn’t change the fact that technology would be retained for those who survive.
There are (and have been) people starving and being slaughtered all over the world in fairly large numbers. If you were to increase that tenfold, people in the US would still be lining up to get the latest iPhone. Increase it by several orders of magnitude if you like. People here will still be worrying about their Facebook friend-ing or un- or whatever the latest thing is.
So yes, what counts as “global civilization” these days is pretty robust.
I’m not sure how you realistically get to 12 billion people and reduce carrying capacity below 100 millions, but… what if you did? I think that number would meet my criterion of a population that can accommodate diverse expression of the genome, and have electricity and flush toilets and antibiotics and so on.
Robin Johnson says
We [humans] are currently conducting an experiment designed to determine just how many people we can stuff on the planet – sustainable or not. There is still PLENTY of land in Africa, Russia and South America that could be made to produce food for another couple or three billion humans. The USA and Europe produce huge surpluses.
At some point, however, a food crisis will wrack ruin upon South Asia (From Egypt [technically Africa] to Indochina]. China’s population growth has slowed substantially and they have mopney to buy food at market rates. South Asia will not. The political unrest that results will unglue the already poorly governed region. And we may decide to let them starve.
So, we can pack a bunch more in the Americas and non-North Africa. I think South Asia is going to burst at the seams sooner rather than later. Depending on the timing of an implosion of South Asia – we might reach 9 or 10 billion humans easily.
zebra says
@BPL #74,
“Hebrew infusion”
Is this going to be some joke involving seltzer?
Theo says
NSIDC heading: “March ends a most interesting winter” Nice way of putting it. And there was also a new word in there: coterminous ?
Thomas says
#52 Victor
a better url for “Making Sense of the early 2000s warming slowdown” http://www.meteo.psu.edu/holocene/public_html/Mann/articles/articles/FyfeEtAlNatureClimate16.pdf
Hank Roberts says
… While ODS [ozone depleting substance] levels remain high, a large stratospheric sulfuric aerosol enhancement due to a major volcanic eruption or geoengineering activities would result in a substantial chemical depletion of ozone over much of the globe. ”
http://www.esrl.noaa.gov/csd/assessments/ozone/2014/adm/
Mike says
boy, I listened to Dr. Mann per link at 79. It sounds like he is drinking the Hansen koolaid now. As cooler heads here told me last month when I was alarmed about the Feb record temp: dude, it’s one month in an ENSO year! Chill out.
I am chill now. Beautiful weather in the NW. A little warm today, in the 80s, but hey, I got my shirt off and enjoyed the sun.
I think Dr. Mann says on the video that the models have been underpredicting the actual rate and intensity of global warming. Wow, dude, get a grip. I have it on good authority that the models are solid, so this stuff will all smooth out. I read that there is some controversy about smoothing, pixel size etc. Not to worry, it gonna be fine.
I sorta locked on to Dr. Mann’s concern about 405 ppm from 2014 and that got my knickers in a knot, but now that I know that the CO2 ppm is not really the number to watch closely I feel great. My blood pressure is down, my cholesterol is looking great, I think I am even regrowing a little hair up on top where I thought global warming was starting to burn out my follicles. It’s all good. IEA numbers are the ones to watch, right? They are solid.
I glanced at the MLO numbers out of habit and read this:
Daily CO2
April 6, 2016: unavailable
April 6, 2015: 404.35 ppm
CO2 not even available. Those IEA fuel consumption reports have solved the problem.
I refuse to worry anymore. I just need to keep hearing from Ray, Hank, Mal and a few others that there is nothing to worry about and I am happy as a lobster in the aquarium at Red Lobster.
Also, elated to hear that DU is safe and not fissionable except under extreme circumstances. I was cleaning the garage and found some DU in box of weird stuff left by previous homeowner. Those folks were a little sketchy and I knew I would be cleaning up after them. Gotta stop and play with my grandson. He really loves the DU junk.
Maybe some of you folks can talk Dr. Mann down off the ledge. If a person sees something that alarms them, I figure holler WOW once and then relax. That covers it, right?
sidd says
Thanx for the link, Prof. Mann. The main disagreement seems to be in the bimodal distribution of NH hydro in the twentieth century in the model simulations but not in paleo reconstruction (Fig 3.) Bimodality is not clearly seen in previous centennial simulations or paleo reconstruction, so comparison of bimodal representation in previous centuries is difficult. We may have perhaps some insensitivity to bimodal anomaly in paleo, as indicated by better rain gauge agreement with modelling.
Has anyone tried this as a global comparison ? No millennium+ records in SH ?
Geoff Beacon says
Chris Machens #75
BBC & A FEW CONSPIRACY THEORIES.
I’ve been complaining to the BBC for years but it’s like nailing jelly to the wall. However,the search term “BBC climate denial” is a good one to use.
One of the many results is a report in the Washington Times,“BBC staff ordered to stop giving equal air time to climate change deniers”
This weakens my prejudice against the BBC Trust – a bit. I have them down as bad guys, mainly because the chair is on the board of Pepsico and allow the BBC to be much to business friendly, without admitting the connection between economic growth and greenhouse gas emissions.
It was good to see the Trust giving the BBC a ticking off but even after that the BBC got Quentin Letts to do a hatchet job on the Met Office, “What’s the point of the Met Office”. Now the BBC have cancelled the Met Office contract for supplying them with weather forecasting.
Actually I don’t completely trust the Met Office now because they may be being softened up by this government for disposal to the private sector. Their sponsoring department is the Department of Business Information and Skills, who inherit much from the old Department of Trade and Industry (DTI). On the sale of a very expensive radar system to Tanzania
Claire Short MP said in Parliament
I suspect the Met Office is under pressure from BIS. Their scientists do meet with BIS officials.
Back to the flawed BBC. They are being further tamed with Rupert Murdoch in the background: “George Osborne under pressure to reveal if meeting with Rupert Murdoch preceded announcement of BBC cuts”
Ex insiders will tell you the BBC was tamed years age. Even before they cancelled “Planet Relief” in 2007..
MS says
It would be nice to have comments on this new study:
Observational constraints on mixed-phase clouds imply higher climate sensitivity
Abstract
Global climate model (GCM) estimates of the equilibrium global mean surface temperature response to a doubling of atmospheric CO2, measured by the equilibrium climate sensitivity (ECS), range from 2.0° to 4.6°C. Clouds are among the leading causes of this uncertainty. Here we show that the ECS can be up to 1.3°C higher in simulations where mixed-phase clouds consisting of ice crystals and supercooled liquid droplets are constrained by global satellite observations. The higher ECS estimates are directly linked to a weakened cloud-phase feedback arising from a decreased cloud glaciation rate in a warmer climate. We point out the need for realistic representations of the supercooled liquid fraction in mixed-phase clouds in GCMs, given the sensitivity of the ECS to the cloud-phase feedback.
Link http://science.sciencemag.org/content/352/6282/224
Is this a new way of constraining climate sensitivity?
Kevin McKinney says
#82, zebra–
I’m not so sure. Modern civilization runs on logistics & globalized supply chains. Some feel that it’s robust to shocks of all sorts, but I don’t think that’s ever been tested, and probably not even examined very thoroughly. In fact, I don’t know that the system has ever been well described and characterized from that perspective–it keeps changing, for one thing, on time frames comparable to the length of big research projects, so my perception at least is that it would be pretty hard for researchers to ‘keep up.’
So I can’t help but wonder, in the event of serious disruptions to social structures, just how deep the destruction can go. Many of the ‘crucial resources’ tech runs on are manufactured–microchips, for one salient example. And last I heard there was considerable manufacturing capacity of the latter in some vulnerable areas, such as the South Asian region, mentioned by Robin in #83. Lose those resources, and specialist skills become irrelevant, almost instantly. Large chunks of the population could go from productive to economic liabilities very fast.
Essentially, I imagine a very sudden mismatch between skill sets and available resources. Highly competent people in huge numbers suddenly become neophytes, for practical economic purposes. Many of them probably die, but the mortality rate for their skills is even higher. The survivors are those whose skills match available resources better–which means what’s left of natural and manufactured resources.
Surely we’d have some McGyvers and Mark Watney types, who’d excel in ‘sciencing the shit out of’ such bad situations. And they’d have a strong survival edge, because they’d be valuable to whoever holds or achieves power in what is likely to be a chaotic social/political situation. But they might well be more scavengers than producers, technologically and scientifically. In short, I suspect it might get pretty damn bad in the worst case, easily justifying a ‘new Dark Ages’ label. I doubt it would be a carbon copy of the last time; probably some modern knowledge would persist at least in some places. (And the original Dark Ages did manage to produce innovations, too, a fact often overlooked–Asimov, for instance, wrote about the moldboard plow as one example. Gunpowder would be another.)
I don’t see this as inevitable by any means; I think we’re currently seeing departures from a pure BAU scenario, and I think that there will be acceleration of that trend. But I do think it’s possible.
Turning to Chuck’s question at #69–“Who expects a population crash by 2050?”–as being relevant here, I don’t ‘expect’ it, largely because I think we won’t realize the worst sort scenarios. I think that we’re going to see continuing decreases in carbon intensity on a global level which do a lot to mute the BAU emissions growth we would otherwise see. I think that we probably will not, however, do enough to avoid 2 C warming, and I think that we’ll see pretty drastic effects as a result. I think that those will include some very nasty high mortality events–hot spots could include South Asia, as Robin said, but IMO also Africa, where we have high population growth, low (but very uneven) economic development, strong climatic and ecological gradients, and in many cases persistently very poor governance.
I can only guess at gross population impact.
I very much doubt we’ll see anything of the kind by 2030 or 2035, but I’m not so sure about 2050. It may come down to the definition of ‘crash’. I don’t find a quantitative definition, but in the classic ecological studies we’ve talked about here previously, we’ve seen fast reductions by an order of magnitude or so–in other words, 90% mortality rates. I don’t think that’s likely for the global human population, at least on decadal timescales, because despite my point about globalization above, the geographic dispersion does still provide a significant buffer. But–should I live so long myself–I wouldn’t be shocked to find that cumulative first- and second-order climate change effects by 2050 prevent global population from ever reaching the 9 billion mark.
Hank Roberts says
Oops.
Dang.
http://www.upi.com/Science_News/2016/04/07/New-cloud-study-offers-dire-global-warming-outlook/4301460057349/?spt=mps&or=5&sn=sn
(The UPI story says the publication is in Nature, but that story’s “Nature” link opens this Science article)
__________________________________________
Observational constraints on mixed-phase clouds imply higher climate sensitivity
Ivy Tan1,*, Trude Storelvmo1, Mark D. Zelinka2
1Department of Geology and Geophysics, Yale University, New Haven, CT 06511, USA.
2Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
*Corresponding author. E-mail: ivy.tan{at}yale.edu
Science 08 Apr 2016:
Vol. 352, Issue 6282, pp. 224-227
DOI: 10.1126/science.aad5300
Hank Roberts says
p.s., check with a reliable source before freaking out about this recent paper. I suggest starting with appropriately skeptical comment:
http://julesandjames.blogspot.com/2016/04/climate-sensitivity-is-53c.html
Chris Machens says
Alan Robock: We need to move ahead aggressively with the grid and battery technology http://climatestate.com/2016/04/08/alan-robock-we-need-to-move-ahead-aggressively-with-the-grid-and-battery-technology/
Pete Best says
Re #58:
I don’t think we presently have a clue how to implement the Paris agreement technologically. Sure we have for two years running prevented fossil fuel usage from increasing even though globally the world economy has done so but as yet was it down to increased renewable deployments or other factors and is this a long term trend or just a blip?
The world uses 20% of its energy in electric form and 80% in other forms so wherever possible switching to electricity (Tesla Model 3 EV for example) could be a way of mitigating if the electricity is sourced from renewables.
Its a big tough situation and no certainties as yet.
Ray Ladbury says
Zebra,
So if transport breaks down, you’ll be able to grow sufficient food for you and your family to make it through Winter? And when your computer breaks down, you’ll be able to build new electronics in 22-nm feature size CMOS? And you know where to get potable water and how to treat it? And you’ll know what to do when one of your children gets severe diarrhea and becomes seriously dehydrated?
The problem is that our technological society is highly specialized, and it is unclear how robust it is, given that specialization. Don’t count on the rich world being able to raise the drawbridge and watch while the vast majority of people die. Many of the most vulnerable live in areas that are quite technologically advanced, and they are quite capable of cyber attacks if they feel abandoned. So don’t count on being able to G**gle how to survive.
Will civilization collapse if we have a very disorderly population collapse? I don’t know. However, I am far less sanguine than you that anything resembling an advanced technological global civilization will exist 200 years from now.
Mike says
This can’t be right:
… new research … suggests climate models have overestimated how much ice is in clouds, meaning less is available to be converted to liquid as temperatures rise.
“When carbon dioxide concentrations and temperatures rise, then mixed-phase clouds will increase their liquid water content,” said Ivy Tan, a PhD candidate at Yale University who led the research, which investigated common clouds that contain both ice and water. “Many models are overestimating how much ice is in the mixed-phase clouds.”
http://www.climatecentral.org/news/clouds-play-lesser-role-in-curbing-warming-20221
I have it on good authority that there is nothing wrong with the climate models. I heard it right here last month when I opined that the models might need some work. Can some of you folks here in the comment community send a quick message to Ivy Tan and straighten this out please?
Beautiful day in the NW, going to hit 79 and I am taking grandkids to the park to play. I was worried about the world we were leaving them, but since I was told that global warming is not going to be a big problem until 2100 I have relaxed. Neither me or the grandkids are likely to live that long. No worries!
CO2 bounced back today for those of you are still worried about that number:
Daily CO2
April 7, 2016: 407.74 ppm
April 7, 2015: 404.65 ppm
407.74 seems like a big number, but so what? It’s only 3ppm over last year this time and it’s an El Nino year. It’s going to drop like a rock thanks to the IEA reports of fossil fuel burning. That is the number we need to be watching now, right?
I do think it’s time to stop the end times talk and get back to climate talk. Things are looking rosy for us all, are they not?
Warm regards
Mike
S.B. Ripman says
From an article just out in the NYT, regarding a new paper by Amy Tan et. al.:
“The computer models that predict climate change may be overestimating the cooling power of clouds, new research suggests. If the findings are borne out by further research, it suggests that making progress against global warming will be even harder.
“The new paper, in the journal Science, focuses on what are known as mixed-phase clouds, which are found around the world and contain both cooled water and ice crystals.
…
“The new paper suggests the effects of a flaw in the model could be serious: Based on its analysis of one model of climate change, the cloud error could mean an additional 1.3 degrees Celsius of warming than expected.”
http://www.nytimes.com/2016/04/08/science/climate-models-may-overstate-clouds-cooling-power-research-says.html
According to a Wikipedia article on Richard Lindzen, “ … he … believes that decreasing tropical cirrus clouds in a warmer world will allow more longwave radiation to escape the atmosphere, counteracting the warming.”
Is this new paper by Tan et. al. another nail in the coffin for the theories of Prof. Lindzen?
Is the “additional 1.3 degrees Celsius” as bad as it sounds?
[Response: I think the press on this paper was pretty bad, and while it’s interesting work, it doesn’t have the implications that have been described (see this set of tweets for some more). I’ll see if I can’t write more about it this weekend. – gavin]
Mike says
Boy, this piece in Nature is pretty ridiculous.
Post-invasion demography of prehistoric humans in South America
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature17176.html
Some folks are reading this and thinking that our species is headed for a population crash. Complete drivel. Do they have any idea how many of us are here? Have they factored in that we will fight anything that looks like a population crash?
Going for a walk, beautiful day, maybe a trifle warm.
Mike