What do you think of the 1500 year natural warming cycle theory?

Question

Historical evidence suggests past warmings have been more intense than the present one, at least if there is no significant further warming.

The historical evidence is well documented and clearly points to conditions that could only be caused by warmer temperatures than we are presently experiencing.

This begs the question. Are the current conditions really exceptional as many AGW believers would have us believe. Would they try to erase history to convince us of their position?

http://www.cgfi.org/2008/08/27/global-warming-every-1500-years-what-it-means-for-engineering-by-dennis-t-avery/

Answer 1

Since the last MWP was only 1000yrs. ago we are hitting the warmth period period too soon. This is the reason the scientists are alarmed. At this rate, and nothing appears to be altering the increase in warm house gases, we will attain a temperatures that will rival those of 72,000 to 60,000yrs ago and that knocked us down to an estimated 10,000 people scattered world wide. In some cases, there was no viable populations.

Answer 2

Only that the climate has changed several times over the last 1500 years-- possibly this guy can lend a hand.

http://wmbriggs.com/blog/2008/08/21/suci...

Answer 3

ok so i am going to go with what a bunch of farmers* think about climate change, rather than the scientific consensus? hardly. especially as the first two 'examples' are our old friends 'grapes in england' and 'settlements in greenland'. yawn. get some more convincing evidence, please, i would really love someone to prove this (in my dreams)

* no offence, i work on the land myself. if i wanted to know about the effect of soil moisture on germination rates, i wouldnt ask a climate scientist....

'farming'? they were on the same lattitude as norway and iceland, where they came from. sure they farmed. hard life, but better than hanging for murder. probably mostly cattle though, i doubt it was grain crops much, maybe a bit of barley. afaik, they traded with the burgundians, swapping trapped animal skins for grain, cloth and wine etc..

Answer 4

I believe you AGWers confuse the words theory and fact.

Anthropogenic Global Climate Change is theory.

Natural climate cycles are fact.

Answer 5

No one, least of all real scientists, disputes there are natural warming cycles.

However, scientists investigated the possibility that our current global warming could be due to natural causes over a period of years. The short answer is that it is not--it is due almost entirely to human action.

Did it ever occur to you that scientists who actually know the field might have thought of that and checked the possibility? Well, they did.

Answer 6

There are numerous cycles.  The most important in terms of global warming is the Milankovitch cycle.

This chart gives a good history of recent cycles.

http://en.wikipedia.org/wiki/Image:Carbo...

This site includes a number of other cycles,

http://en.wikipedia.org/wiki/Solar_varia...

the most well known (11 years) as well as 22 years,  87 years, 210, and 2300 years.  There may be other cycles such as one that seems to be about 60 million years old.  \

These are  the scientific facts.  Suggesting that CO2 is necessarily causing significant or harmful warming is gross speculation that has more to do with world view and politics than science.  Alarmists try to suggest that recent warming must be due to man, yet current climate falls within natural variations so their conclusions become probematic.  They try to settle this delima by pretending that it has never been as warm as today, or not in the last 100,000 years, and they try to gloss over the fact that climates change.  The fact is climates change dramatically and have since we entered our current ice age.

Sophist is probably refering to the Toba volanic eruption 75 thousand years ago.   This is what theoretically reduced our population, at least I have not heard any credible theories that suggest it was warming.   I have heard ridiculous theories that global warming wiped out the dinosaurs (ridiculous IMO).

Answer 7

I think it can't explain the current warming.

Just think about it - the last fairly warm period was the MWP about 1,000 years ago.  The 1,500 year natural cycle theory doesn't fit.

In a paper by Stephen Rahmstorf studying this cycle, he concluded that when the cycle occurs (which is not consistently), it's every 1470 +/- 150 years, and that there haven't been any occurances in thousands of years.  See Figure 1 in the first link below.

Blaming the current warming on this Dansgaard-Oeschger cycle requires some really gross data manipulation, as discussed in the second link below (again by Rahmstorf, who is the expert on the subject).

So then the question is who are you going to listen to - a food policy analyst who doesn't even support this 1500 year cycle argument, or the scientist who actually studies these cycles?

Answer 8

This is not a precedent by any means, but the alarmists have chosen to fudge the data to make it work in their favor.  Current conditions of a warming of .6deg.C. from 1900 to 1998, and then no further warming, are completely normal and indicate that in truth there is nothing to be concerned about.  

Answer 9

more real than the AGW group can conjure up.

Answer 10

Why would I get climate science from a Center for Global Food Issues? Are you trying to say climate scientists haven't thought of that? I think I'll listen to the National Academy of Sciences over a think tank...

http://dels.nas.edu/dels/rpt_briefs/clim...

Answer 11

Not much.  

The data shows it isn't true.

http://www.globalwarmingart.com/wiki/Ima...

The hockey stick did overly smooth the data, and the MWP doesn't appear.  But the National Academy of Sciences says it was basically correct.  It's been repeatedly duplicated with better statistics, showing the MWP as it actually was.  Less warming than today, much slower.

http://www.globalwarmingart.com/wiki/Ima...

Answer 12

I freaking love it! Thank god I have the opportunity to live during such a mild climate. The 1700-1800's were extremely tough on humans.

But a better question may be, how do you like living during the 120,000 cycle? See graph if you do not understand this reference.

http://en.wikipedia.org/wiki/Image:Ice_A...