We are harangued about the horrors and EVIL that will befall us if the world warms even 1/2 degree C. We are told that at 2 C it is the end of life as we know it. The world will end in a drowned plague ridden state. Is there any way to check this? Some way to ask: “What would the world be like if it was a little colder, or a lot warmer?”
Well, I think there is. We’ve seen this 11,000 year temperature chart before. It is for Greenland, so not exactly representative of Europe, but it does live in the area and the weather of Europe does come from the same general areas. The other chart here zooms in on the last 1000 years. It’s hard to read in the long duration chart. We’re interested in about 1320 AD. On the long chart it is barely a wiggle. Looks like about 1/2 C colder. So lets look at this 1000 year chart to get a better idea.
You can see that in about 1320 AD most of the lines are near the same position with only one turquoise colored tree ring series a bit out of agreement. We are now, if the numbers are to be believed, about 0.4+ warmer than the zero line, while then they were about -0.2 cooler. Call it from 1/2 to 2/3 of a degree of C colder.
The (now somewhat discredited) Warmers are absolutely sure they want that 0.4 C to be removed, and one can only presume they would like an added 0.2 C of safety net too. In theory, that time just before the L.I.A. is an ideal time. It is just a touch cooler than the 1200s, and they seem to think cooler is better, so lets use it. (Personally, I don’t see any way at all we could managed the temperature to within a 2/10 range in either case). But lets assume we get headed down to Nirvana. What does the world look like then? We’ll see shortly.
One the other end, lets pick a big hot spot from the past. A time of horrors when pretty much everyone says it was warmer. The Holocene Optimum. Right around that 8.2 kyr event. Nice big spike up in temperatures just before it. Must have been a load of “climate chaos” then. I make it a bit over 2 C higher than now on this graph between about 8,000 and 9,000 BP (about 7,000 to 8,000 in Carbon Years – this matters as a map down below is in Cyr BP). It is clearly a whole lot more ‘warm’ than that little dip at 700 BP / 1300 AD.
What happened in 1300 AD?
(Winter) Severe winter (London/South). A severe winter over much of western Europe. (Easton, in CHMW/Lamb): taking these two last entries together suggests a high frequency of blocked / anticyclonic episodes.
1309/10 London Bridge arches damaged by ice during a severe winter. Thames frozen. A possible frost-fair on the Thames in London; which implies a persistent length of sub-zero temperatures at some time this winter (inferred by the statement in some chronicles that ‘sport’ was held on the river). Usual stories about people walking across the Thames. According to contemporary reports ” dancing took place around a fire built on the ice and a hare was coursed (chased) on the frozen waterway “.
Several famines occurred during these years (weather assumed to have been responsible, with all three years noted by various historians as ‘very wet’ … it’s a moot point though as to whether all three were really wet, or just the effects of one or two carrying over). Brazell says that the famine of 1316 was probably the last really severe one in England, and historians have estimated that over this period, roughly half-a-million people died of causes related to famine, which represented approximately 10% of the population. [ The wet year credited to 1315 may be the origin of the St. Swithin legend. ]
The ‘Black Death’ (Bubonic plague) that ravaged the country 1348 onwards may have some linkage to these precursor conditions – though it is a long time afterwards. Certainly though, in the mid-1300’s, mortality was high due to famine, disease etc.
It is suggested that it was an increase in climatic variability, rather than the absolute temperature & rainfall regimes that caused the problems. There is some suggestion of an increase in extreme events (including wind-storms), however defined. Some evidence that as well as excessively damp conditions, temperatures were depressed.
1338/39 Hard frost started in December and lasted for 12 weeks. (London/South). Also, from the ‘Annals of Dublin’ (http://www.chaptersofdublin.com) .. “So great a frost was this year (AD 1338) from the 2d of December to the 10th of February, that the river Liffey was frozen over so hard as to bear dancing, running, playing foot-ball, and making fires to broil herrings on. The depth of the snow that fell during this frost, is almost incredible; yet it is agreed, that such a season was never before known in Ireland”.
January 1362 ” St. Mary’s Wind “: A severe gale / storm (at least as powerful as that of October 1987) from between south and west commenced on the 15th (23rd new-style) January 1362 and lasted for about a week – affecting large areas of southern Britain. A large number of buildings were blown down or damaged, including St. Pancras Church, the church of Austin Friars in London, Norwich cathedral and the (original) Abbey Gateway in St. Albans. Damage also to shipping. The “exceptionally ‘severe gale’ caused great destruction – buildings, towers, trees, wind-mills etc., all ‘thrown down’ according to contemporary chronicles. Noted by English, Scottish & Irish sources.
The “Great Drowning” (‘Grote Mandrenke’) causing widespread / severe damage across SE Britain – also along the East Coast, and as 60 Danish ‘parishes’ are noted as having been ‘swallowed up’ by the sea, with several thousands dead there, it suggests a rapidly-deepening low moving swiftly across southern Britain and the southern North Sea with a high storm-surge event.
(Might have been a sequence of events I would have thought, with perhaps the main-event on the 15th). This storm is regarded as the severest on record for the area, with the exception of that in November 1703 & possibly October 1987.
(Winter) A cold winter in western Europe / implied parts of Britain. (Easton, in CHMW/Lamb) 1
(Winter) A cold winter in western Europe / implied parts of Britain. (Easton, in CHMW/Lamb)
Now I’ve cherry picked this list a bit. There were a couple of years listed with ‘warm summer’ and such, but I wanted to show that this whole century had a lot of very cold events. Also, we are interested in what happens in the cold times, not the hotter ones. so looking at the impact of the ‘little bit colder’ on the cold events informs what we wish to learn.
Hmmm, not liking the looks of that 1316 Famine. Perhaps a bit more on it would be of use:
The Great Famine- The beginning of the 14th Century is marked by one of
the great disasters of human history. The rain started in 1315, and
continued particularly in the summers for 7 years. Like the 6th century
famines, this event changes everything. Unlike the 6th century famine, we
have much better records this time around. The history of this famine relies
on combining studies of skeletons, tree-ring-growth, and analyses of
infrastructure with accounts in chronicles and records of taxes, rents, and
the admission of new burghers to town institutions. Much of this information
is conveyed in numbers: dates, grain yields, weather data, prices.
Decrease in the food supply was not limited to a drop in grain production,
but extended to epidemics in herds and flocks and an acute drop in the
supply of salt needed to cure meats and fish that might have supplemented
the reduced supply of grain. Wars diverted resources to military needs that
might otherwise have been used to feed the hungry. A century of benign
weather had lulled individuals and communities into a state of unreadiness
for such an extended drop in production. Seven years of rainy summers
and cold winters brought one disaster on top of another. Foremost, of
course, was low productivity in grain crops. Already in the late thirteenth
century, yields in the colder parts of northern Europe and on “marginal”
lands were as low as 2:1 (2 bushels for each bushel sown) and probably
nowhere higher than about 7:1.
OK, a couple of things. 1316 is just about a 1/2 Bond Event (or one Smith Event ;-) interval prior to ‘now’. If my thesis hat there is a 700 ish year sub-cycle has any validity, we ought to be seeing similar patterns as things roll forward.
I see one similarity already. “A Century of benign weather”. Isn’t that pretty much what we’ve had? We left the Little Ice Age in the mid to late 1800’s and it’s been pretty nice ever since. Very warm in the 1920’s to 1940’s. Spectacularly benign in the 1980’s and 1990’s. We certainly have been “lulled” a lot, and global food storage is approximately 6 months if we are lucky (in many places it is near zero).
So the ‘lead in’ to this event is looking similar. We’ve been a bit warmer, per the graph, so may have it somewhat better as a lead in, but the result has been the same. And when it got cold and started to rain with attendant crop failures? Oh, a famine. In this case one that had several years of crop failures.
You can read the rest of the story at the link. Wars. Black Death. Cannibalism. (Not a whole lot, just a little ;-) And that is when they were starting with a whole lot more “preparedness” in their kits:
Medieval people were accustomed to the vagaries of weather and
resultant poor harvests. No town or manor was without some
infrastructure for storing excess grain from bountiful harvests in
anticipation of the occasional bad one. But, there is strong evidence that
the thirteenth century had been an extended period of balmy weather and
relative plenty. Barns and drying ovens were too few and too small to
store grain to last through more than one bad harvest. Indeed, Europe
weathered the crisis of 1315 relatively well. It was the continued bad
harvests of 1316 and 1317 which brought widespread death and disaster.
So about that Biblical command to store a few years of food?…
Was this just a British thing?
1314 – 1317 AD Great European Famine – The worst famine to strike Europe occurred between 1314-1317. It was widespread, affecting all of Northern Europe. Eyewitness accounts tell of the poor and hungry resorting to eating cats and dogs.
Well… looks like it was rather wide spread.
We don’t have any history from 9000 years ago. So just a couple of maps will need to do. We keep hearing how any warming at all is just going to cause Africa to dry up and blow away. Rampant famine is just around the corner. It can bring no good, only a horrid end of humanity. So what was Africa like when it was a couple of degrees C warmer?
Golly. Grassland and savanna as far as the eye can see, even covering Saudi Arabia… There would be an explosion of life and more grain growing area than can be imagined. Almost like a garden of Eden…
How does that site describe it?
8,000-7,000 14C y.a. (about 9,000-8,000 ‘real’ years ago). Forest extent in central and western Africa seems to have been at about its maximum around this time. For example the Oyo site in the east-central Sahara had it moistest climates and greatest vegetation cover between 9,000 and 6,000 14C y.a. (Ritchie 1994). (See main QEN review for 8,000 14C y.a. timeslice). Due to the much greater rainfall, Lake Chad (in the southern Sahara) was greatly expanded in area during all or most of this phase, and surrounded by extensive inter-dune wetlands.
It is almost beyond doubt that there was an expanded area of the central and west African rainforest areas at this time. Schwartz (1991) has found soil isotope evidence that areas now covered by savanna in central Africa were forest at this time, and a forest expansion south of the Equator is supported by the pollen evidence of Elenga et al. (1993), which shows that the present forest-savanna mosaics were more heavily forested. The generally northward movement of monsoon rains into the Sahara region can be expected to have resulted in a northward expansion of rainforest as well, and this does appear to be the case from the pollen record (Lézine & Vernaud-Grazzini 1994). A conjectural boundary for the rainforest zone is drawn here.
Forest and woodland areas in the rift valley region of east Africa also seem to have been more extensive around this time (Vincens 1991, Maitima 1993).
A severe arid phase (correlated in many places around the world) seems to have affected North Africa around 7,500 14C y.a. (Alley et al. 1997, Gasse & van Campo 1994), perhaps lasting for a century or two. There was a reduction in Nile flooding, in NW Sudan lake levels, and at sites in the western Sahara, the Sahel and sub-equatorial Africa (Gasse & Van Campo 1984, Lario et al. 1997).
We can even see that arid cold phase at 7,500 C14 BP (or about that 8.2 ky event). Gee, a cold event bringing drought and causing problems…
How about Europe?
7,000-5,000 14C y.a. Warmer-than-present climates allowed forest to spread further north. There are various sources of evidence for warmer summer and winter temperatures across northern Europe during the mid-Holocene (e.g. Vork & Thomsen 1996); these include pollen evidence of plants extending further north, and aquatic and terrestrial invertebrates. The diverse data have been been summarized into climate map reconstructions, indicating about a 1 deg.C warming in mean July temperature at 50 degrees North, a 2 degrees warming above 60 degrees North, and 3-4 degree warming above about 65 degrees North (Klimanov et al. 1992). A winter warming of about 2 degrees is suggested for most of north-west Europe (Klimanov & Velichko 1992). The available indicators do not all agree on the same time slices or intervals for maximum warming, but in general it seems that the period between 7,000 and 4,000 14C years ago includes the warmest part of the Holocene in most areas.
Lake level evidence (Harrison et al. 1996) suggests that the mid-Holocene climate may have been somewhat moister than present across the northern Mediterranean region, but slightly drier in northern Europe.
A severe cold and dry event, lasting perhaps a couple of centuries, shows up in the Greenland ice cores around 7,500 14C y.a. (8,200 cal. y.a.) and has been correlated with cold and aridity (but with moister conditions in NW Europe; see below) in many parts of the world (Alley et al. 1997). The temperature lowering in the north Atlantic seems to have been about half-way as severe as that associated with the Younger Dryas. It is possible that this cooling event would have extended across Europe, and a rapid cooling (and onset of wetter peat-forming conditions) has indeed been noted by Anderson (1996) for NW Scotland at about 7,400 14C y.a.
During the 7,000-5,000 14C y.a. time interval, agriculture spread to most parts of Europe. By around 7,000 14C y.a., occasional burning of the forests by humans may have caused an increase in the fire-resistant cork oak (Quercus suber) in the Sierra Nevada of southern Spain (Rackham, in press). Cereal and olive pollen also begin to appear soon afterwards, suggesting sporadic cultivation.
By about 5,000 14C y.a., spreading peat growth was beginning to affect the forest areas of NW Britain, perhaps due to ongoing leaching of soil nurients, with occasional forest clearance for agriculture accelerating soil leaching and allowing the beginning of peat buildup.
Well, we can again calibrate off that 8.2 Kyr event. It looks like we continue to have “warm is good” with more life, more trees, more growing.
China did OK too:
Eurasia during the early Holocene – 9,000 14C ya
8,000-7,000 14C y.a. By 8,000 14C y.a., forests in most areas of northern Eurasia were at least as thickly wooded as they naturally would be today. Conditions remained considerably warmer and moister than at present, with much greater vegetation cover in desert regions, northward extension of warm temperate forest belts in China and Japan (Winkler & Wang 1993, Petit-Maire & Gua 1996). There was probably greater forest extent in south Asia due to a stronger summer monsoon in India (suggested by both land-based and oceanic indicators of monsoon strength in the region; e.g. Cullen 1981, Zonneveld et al. 1987) and in Indo-China (e.g. Bishop & Godley 1994). Evidence from this time interval is discussed in detail on the main QEN review.
Eurasia during the early-to-mid Holocene – 8,000-7,000 14C ya
6,000-5,000 14C y.a. Plant fossil and sedimentological evidence suggests that conditions remained moister and warmer than at present, with forest vegetation exceeding its present limits in most parts of Eurasia (Winkler & Wang 1993). Lake level evidence from widely scattered areas across Eurasia (western Siberia, Mongolia, Yakutia and China) also suggests moister than present conditions at this time (Harrison et al. 1996). Petit-Maire & Gua (1996) suggest that the paleosol record in north-west China indicates a relatively arid phase 6,500-5,500 14C years ago, though with a return to peak Holocene humid conditions 5,500-3,800 14C y.a. .
Evidence from this time interval is discussed in detail on the QEN web page.
Klimanov (1992) has reconstructed February temperatures for the interval 6,000-5,50 14C y.a., based upon a range of biological and geomorphological indicators. He suggests that all of Siberia had winters at least 1 deg.C milder, with central Siberia being 2-3 deg.C milder. August temperatures from central Siberia northwards are also suggested as having been at least 1 degree higher, with a warming of 2-4 degrees along much of the northern coast of Siberia (Klimanov et al. 1992).
Oddly, they have poorer maps and less information for North America. Possibly as the ice sheet is thought to have hung around longer, slowly melting. The best I can get is this map from about 5000 BP. Not quite as warm as we’d like, but OK.
Even the deserts of Nevada and Arizona are marked as ‘semi-desert’… Lots of forest, savanna, and grassland too.
It looks to me like we’ve got a pretty clear A / B case here.
Much colder, things go to hell pronto. People die. Starvation happens.
Much warmer, we get a bit more warm rains, lush growth, vastly more food growing areas.
I’m just not seeing the problem here. Global Warming? Bring it on! PLEASE!!