Our “recent” (geologically speaking) temperature history:
By Lawrence Solomon in the Financial Post
Thank your lucky stars to be alive on Earth at this time. Our planet is usually in a deep freeze. The last million years have cycled through Ice Ages that last about 100,000 years each, with warmer slivers of about 10,000 years in between.
We are in-betweeners, and just barely — we live in (gasp!) year 10,000 or so after the end of the last ice age. But for our good fortune, we might have been born in the next Ice Age.
Our luck is even better than that. Those 10,000-year warm spells aren’t all cosy-warm. They include brutal Little Ice Ages such as the 500-year-long Little Ice Age that started about 600 years ago. Fortunately, we weren’t around during its fiercest periods when Finland lost one-third of its population, Iceland half, and most of Canada became uninhabitable — even the Inuit fled. While the cold spells within the 10,000 year warm spells aren’t as brutal as a Little Ice Age, they can nevertheless make us huddle in gloom, such as the period in history from about 400 AD to 900 AD, which we know as the Dark Ages. We’ve lucked out twice, escaping the cold spells within the warm spells, making us inbetweeners within the inbetween periods. How good is that?
We aren’t alone in having been blessed by good weather. About 2000 years ago, around the time of Caesar and Christ, temperatures were also gloriously warm, some say much warmer than those we’ve experienced in recent decades. That period — the centuries immediately before and after Caesar and Christ — are known as the Roman Warm Period, a time of wealth and accomplishment when the warmer weather filled granaries and extended grape and olive growing regions to lands that had previously been unarable.
Another period of unusual warmth came about 1000 years after the Roman Warm Period, during the centuries before and after the year 1000, in what is known as the Medieval Warm Period. In this period, again warmer than the present time, the world shucked off the insularity of the Dark Ages to allow civilization to once again blossom. England, then positively balmy, became a grape-growing region. In the North Atlantic, the Arctic sea ice released its grip over Greenland, making this vast island hospitable for Viking settlers. In the Canadian Rockies, majestic forests — trees larger than those of today — thrived before their decimation by the glaciers that came in with the Little Ice Age.
Another 1000 years and we come to our time, known to climatologists as the Modern Warm Period. What a great time of technological and cultural advancement we’ve known, one of unprecedented prosperity, human longevity, and human comfort. For a brief period in the 1970s it appeared to some scientists that the climate that had abetted our prosperity had turned — this was the fear of global cooling that then made headlines. Though many now mock those fears of climate cooling, the scientists were eminent and the science was sound — after all, given Earth’s history through the eons, and the passage of 10,000 years since the last ice age, it was hardly outlandish to believe that time of warmth was up.
It wasn’t then — the decades after the 1970s have been about as good as it gets. But it could be now. In fact, some of the same scientists who in the 1970s warned of a new cold spell still believe it could be imminent. Other eminent scientists with compelling new evidence have recently joined them in predicting the end of our Modern Warm Period. They and others note that the warming of the planet stopped 11 years ago and that the planet has begun to cool.
If a new Dark Age does come, it could be rapid, marked by plunging temperatures and extreme weather events. Such was the transition from the Roman Warm Period to the Dark Ages and from the Medieval Warm Period to the Little Ice Age. To date, we have seen no plunging temperatures, no uncharacteristically extreme weather.
If we are living on borrowed time, as the history of the world would suggest, this reprieve would be but one more blessing to count. We should enjoy the warmth while we can, and hope that it persists so that the world our children and grandchildren inherit will be no less warm and welcoming.
Financial Post
LawrenceSolomon@nextcity.com
At the risk of repetition, we do not fully know or understand the trigger(s) which set off glaciation periods, they are rapid and should be studied more rigorously, we need to know (could we do anything about it? – probably NOT).
People may regard me as eccentric but I think that refreezing is a real threat, let us hope not in my lifetime but soon ( in geological time terms) it will happen – as the article says………….. we are due.
It can make you very philosophical about the hype over Political AGW and of ghosts and glaciation:
Hamlet:
“And therefore as a stranger give it welcome.
There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.”
The immortal bard.
Bill Illis (08:50:59) :
Yes, the thin Blue DMI Line.
We came perilously close to dipping under it this year.
All it takes, really, is for the diurnal to shrink.
You could even have the Winter Anomaly rise and the Summer Anomaly drop faster.
In the land of 50 below for 6 months, a 10 degree warmer winter anomaly is meaningless. In terms of civilization, it’s badly misplaced warming. It occurs in the wrong place at the wrong time.
The article is very timely because I’ve been wondering about this a lot.
So what are the conditions that will end this interglacial? I can see the reasoning that this is more like the 400 kyear interglacial but every time I look at the graphs of procession, obliquity, insolation, etc I get the idea that the 400 kyear interglacial started sooner in the cycle than this one and the 800 kyear interglacial wasn’t that long. I’m sure that this impression is because I’m looking at crude representations but I can’t find a good discussion on the subject.
I also conclude that this interglacial is already 15000 years old because of the return to the freezer during the Younger Dryas.
Most articles I’ve read from official sources sort of dismiss the issue by stating that even if they’re wrong about cycle length, increased CO2 would overide a return to glaciation. Since they’re already whining that natural temperature drivers are hiding the CO2 induced warming, it seems highly unlikely that CO2 could stop and ice age.
Can anyone point me to a good source of theories on interglacial end?
Esteemed Glacial Alarmist Richard Alley has something to say about climate stability and rapid change….
http://dujs.dartmouth.edu/wp-content/uploads/2008/04/hadzimaice.pdf
Both Mr Solomon and the IPCC have got hold of the wrong end of the stick about the Little Ice age. There is no evidence whatsoever to indicate it was a 500 year period of unremitting cold. The official view and my ‘conclusions are detailed under.
1) The UK Met office-a prime contributor through the Hadley centre to the IPCC assessments, assert:
http://www.metoffice.gov.uk/climatechange/policymakers/policy/slowdown.html
Extract “Before the twentieth century, when man-made greenhouse gas emissions really took off, there was an underlying stability to global climate. The temperature varied from year to year, or decade to decade, but stayed within a certain range and averaged out to an approximately steady level.”
My Conclusion: This is clearly incorrect as there is proof of considerable cyclical variability throughout history, and we can readily trace those over the last 500 years.
2 IPCC FAQ 6.2 Page114 of TAR4.
‘All published reconstructions find that temperatures were warm during medieval times, cooled to low values in the 16th 17th 18th 19th centuries, then warmed rapidly after that.’
Conclusion. This assertion can not possibly be supported-there were periods nearly as warm as today as well as very cold periods. Current warming is slow and consistent with previous periods in the observed climatic cycles.
This excellent graph below about the LIA warm periods really sums it up.
http://www.ac.wwu.edu/~dbunny/research/global/glacialfluc.pdf
I do agree about the proof of warmer periods than today though, but think Joe’s graph (which surely is identical to Bob Carters) underplays the MWP somewhat.
So sorry, but history tells us that there are huge cyclical variations in our climate, and whilst the LIA undoubtedly had long brutal periods of cold there were many warm periods as well.
I blame Charles Dickens. The Anglo Saxon world has been brought up on the snowy scenes of ‘A Christmas Carol’. He actually wrote this in a summer heatwave, published it during one of the Uk’s warmest ever Decembers and lived through what remains to this day two of our warmerst winters. Not bad going for an unremittingly cold LIA 🙂
To paraphrase the good Dr Mann-The Lia is an outdated concept.
Tonyb
Kevin Kilty (08:52:40) :
‘It’s not all bad. The industrial revolution began during the LIA’
“Suggesting cause and effect? On that hypothesis the Inuit ought to be the most industrially advanced people on Earth.”
That is a Luddite statement. The Innuit fled the cold down to the cold level they could put up with and returned to the far north when it warmed. Besides they believe themselves the most advanced. In their language “Inuit” means, essentially, “human” as distinct from other creatures who walk on hind legs.
There’s no reason to panic about freezing either. Warming is generally an easier engineering task than cooling things – particularly if you aren’t forbidding coal.
Kevin B (09:13:49) :
“…This forecast would be given on the time honoured basis of most weather forecasts – looking at the patterns of the past and projecting them into the future. Despite all the Petaflops available to todays meteorologists, this is probably still the most accurate way of forecasting.”
Reply: I quite agree – pointless looking for detailed info and trends in our non-linear climate system. Without a doubt, broad brush expectations based on history is the way to go when trying to predict the future for our quasi-cyclical chaotic dynamic climate system.
17th century -cooling – Maunder minimum
18th century – warming
19th century – cooling – Dalton minimum
20th century – warming
21st century – cooling – ?
“They and others note that the warming of the planet stopped 11 years ago and that the planet has begun to cool.”
If they and others say that, then they and others are fools. There is no evidence whatsoever to support this claim.
Does anyone know where I can find the data and method for the graph at the top of this post? Thanks in advance.
Just food for thought.
Can you imagine if in 20 years from now we are in the grip of a little ice-age. What would people and historians be writing about our fear of a warming planet? Especially if we had already sacrificed our standard of living in order to reduce C02 output which failed dismally.
Cycles within cycles within cycles. Whether economic cycles or weather cycles, these self-regulating cycles happen; sometimes they bear good news, sometimes not so good news. The real trouble happens when some men imagine they can control self-regulating cycles.
I have been saying the same thing based on my own analysis for years, it is nice to see if validated by an independent source. Since the Roman Warm Period we have been in a significant general cooling trend with each cold period colder than the one before and each warm period not quite as warm as the one before.
It took many parts of Europe until the 20th century to recover their populations that they had in the 12th century. People simply have no clue as to the scale of potential famine we face.
“There is no evidence whatsoever to support this claim.”
This is false.
Any statement along the lines:
“There is insufficient evidence to prove…” would probably be true. But “No evidence whatsoever” is false.
RW (10:45:09) :
[“They and others note that the warming of the planet stopped 11 years ago and that the planet has begun to cool.”]
“If they and others say that, then they and others are fools. There is no evidence whatsoever to support this claim.”
Using the most accurate measure of average global temperature from the UAH satellite data, I think you’ll find no upward trend for the last 11 or so years – in fact you could argue a slight decline, although this is probably within the error bars for the data.
Plot of 1998 to 2009 temperature and trend here:-
http://www.woodfortrees.org/plot/uah/from:1998/to:2009/plot/uah/from:1998/to:2009/trend
RW (10:45:09) :
There is no evidence. I agree.
There has never been, nor will there ever be, evidence of anything.
Nothing to claim, nothing to predict, nothing to prepare for.
Evidently, there is no evidence…. of evidence.
What we need is a confession from the dead.
Oh, that’s right. They wrote to us. But they are long gone.
Whom do you trust?
The living, who seek to profit off your demise, or those whose demise precludes them from profiting off you?
“until the 20th century to recover their populations that they had in the 12th century.”
Meant 13th century (and very early 14th).
Tenuc (11:12:13) :
Using the most accurate measure of average global temperature from the UAH satellite data, I think you’ll find no upward trend for the last 11 or so years – in fact you could argue a slight decline, although this is probably within the error bars for the data.
Measuring temperature directly is so yesterday. The most modern methods are strip bark, varves and womens underwear.
Tenuc:
North American data from NCDC shows a significant decline of North American temperatures at a rate of 0.7 degrees per decade over the past 10 years. That is significant because North America produces most of the world’s food so “global” temperatures notwithstanding, what happens in North American impacts global food supplies. 0.7 degrees/decade is a very fast rate of decline. Continued for another decade, we would see serious impact in reduction of growing seasons and frost kills in the Northern Plains and Canada.
RW said
“If they and others say that, then they and others are fools. There is no evidence whatsoever to support this claim.”
Vicky Pope Head of the Met office admitted to this drop in temperatures . You can hear her say it for yourself. I have her email address if you want to call her a fool but try to be pleasant about it 🙂
Here is the reference.
BBC radio 4 at 12 Septermber 2009, Vicky Pope of the Met office reluctantly admits the climate has been cooling against their expectations and models
http://news.bbc.co.uk/1/hi/programmes/more_or_less/8248922.stm#email
This is the BBC’s Tim Harford item (the link is found at the bottom of the box to the right of the item “Blowing cold, then hot”).
transcript
“Tim: If the cooling that the Leibniz Institute predicts actually takes place, are you worried that ’s going to take the wind out of some of the sails of scientists who are warning about the threat of global warming?
Vicky: It’s very important to realise that there will be ten-year periods where the temperatures don’t increase or they even decrease as the Leibniz study is suggesting –
Tim: We’ve just had one.
Vicky: Yes, in fact we have, but that doesn’t mean that global warming has stopped, it’s simply a question of natural variability, giving a temporary decrease in temperature overlaid on top of a long-term warming trend, and in fact I believe that’s what the results of that study suggest –
Tim: Sorry to interrupt but you say that were going to have ten-year periods of cooling. How can we be sure that the rapid warming we saw in the 1980s and 1990s wasn’t the exceptional period?
Vicky: This is the point really, is that 1998 was exceptionally warm because there was an El Nino, because there was a natural variation overlaid on top of climate change. So what you can see very clearly is a long-term trend and then these periods of rapid warming and less rapid warming or even cooling overlaid on top of that because of natural variations.”
This should also be seen in the context of the New Scientist interview. All I am saying is that the models did not predict the (officially) admitted cooling and they are having to take ‘natural variability’ into greater account. I make no predictions as to whether this is the start of a longer cooling trend.
Tonyb
In light of the ..7 degrees/decade N. American temperature decline, the declaration by Chu (Ah-Choo) that California Agriculture is useless takes on new meaning.
http://www.agriculture.com/ag/category.jhtml?categoryid=/templatedata/ag/category/data/agnewscategory-crops.xml
Articles:
•Testing has revealed dangerous levels of mycotoxins on corn in the western and central Corn Belt.
•Corn molds and diseases.
•Soybean diseases have exploded.
Corn, soybean harvest slowest in 30 years
http://www.agriculture.com/ag/story.jhtml;jsessionid=REXVVEM1MLNUWCQCEAQB42Q?storyid=/templatedata/ag/story/data/1256590252339.xml#continue
Four to six times normal rainfall swamps crops
http://www.marketskeptics.com/2009/10/rains-swamp-crops-and-wash-away-any.html
Plant rusts such as Ug99, which has the designation of TTKS, is a race of black stem rust (Puccinia graminis tritici) wheat rust badly affecting Africa and Asia is spreading fast… Late blight, in cultivated potatoes and tomatoes is still a big problem though some success has been made at developing a disease resistant potato utilizing wild varieties. There are various articles on these to be found with a google search.
http://www.google.com/m/search?ct=fsh&q=UG99+TTKS
I believe the Modern Warm Period will become known as the Chinese Supremacy Warm Period…
And the net 5000 year trend is about zero.
No CO2 involved, just natural variations.
BTW: November here looks like it could be a sizable change from last month, on the warm side, many areas in our state has already had their first freeze while we’re still waiting for it, in fact looking at the forecast looks like the fall color will stay and not go brown and the grass and ground cover will keep growing.
Tenuc (11:12:13) :
Using the most accurate measure of average global temperature from the UAH satellite data, I think you’ll find no upward trend for the last 11 or so years – in fact you could argue a slight decline, although this is probably within the error bars for the data.
Plot of 1998 to 2009 temperature and trend here:-
http://www.woodfortrees.org/plot/uah/from:1998/to:2009/plot/uah/from:1998/to:2009/trend
– that’s very ‘cherry picky’!
– if you move the start date by +/- a year or two, it’s difficult to see a cooling
– I think the best that can be said is that there has been a ‘pause’…
http://www.woodfortrees.org/plot/uah/from:2000/to:2009/plot/uah/from:2000/to:2009/trend