I managed to find an add-on for NASA World Wind that allows me to adjust sea levels. When sea levels were at their minimum things were much different in the Caribbean. There was a land mass between Cuba and Florida. There was much more land off the coast of Florida. There was a huge land mass in the Atlantic Southeast of Newfoundland larger than Nova Scotia.

I am fairly convinced that while Earth’s orbital cycles appear to go in 100K year cycles, they don’t result in causing an ice age. Again, ice age is currently the NORMAL phase. Interglacial is the oddity. I don’t believe that conditions were such 12K years ago to bring us out. My gut says it is due to us living near a variable star. I suspect that we go into a deep solar minimum that results in an increase in albedo that acts as hysteresis. We go into a deep minimum, ice builds up, it causes albedo to increase and the sun goes into another minimum before Earth has completely recovered from the first … and bingo … we start the spiral downward in temperature until we have a combination of both favorable orbital dynamics AND an active sun.

If so, the impact could’ve caused over a thousand yrs of iceage-like climate. One would wonder how the direct effects could last that long — atmospheric debris would have cleared out in mere decades or less. Perhaps long-lasting ocean current shifts were caused by the impact.

http://co2science.org/data/mwp/mwpp.php

Pls patronize the site. They do a weekly update of a new peeer reviewed article which demonstrates the existence of MWP and LIA

The Science Daily article (link posted by Paul (13:57:17) above) is a good summary of findings, but shows a graph that is a hybrid of several in the paper.

As noted above the NH temperature is quite variable – more than Hockey Stick graphs. it is from another paleo reconstruction from mixed sources (A. Moberg, et al., Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data. Nature 433, 613 (2005) – link with graphic (note link to original data below abstract!)http://www.ncdc.noaa.gov/paleo/pubs/moberg2005/moberg2005.html

This in itself is notable for the absence of hockey stickiness. Both the cave data and the other proxy data agree quite well from 750AD to present and suggest Medieval Warm Period temperatures similar to present. The cave data paper does not report a temperature anomaly range; Moberg et al’s plot is +0.1 to -0.9 (deg C) approx by eye.

In the Science paper, in addition to this graph, two other NH temperature series are used, one of which is Mann & Jones, Geophys. Res. Lett. 30, 1820
(2003) – a hockey stick. The range of this anomaly is -0.5 to -0.1 deg. C for most of the construct and -0.1 to +0.1 since about 1900.

They also correlate the data (as a proxy for rainfall/temperature) with Solar irradiance from 10Be and 14C records (about which I am sure Leif would have some criticism) and analyse the isotope data with a univariate spectral analysis ( in on-line supplement) finding 4 periodicities including a 10.5-year period corresponding to the Schwabe cycle of sunspot variability.

Which BTW, makes the last 30 or 40 years unusual on a century scale (ie the 20th century) but not on a millenium scale.

This reconstruction shows the very abrupt cooling around 1600 or a little earlier, which other reconstructions show as -2C to -3C in as little as a decade. Were such a cooling to occur today it would be an unimaginable worldwide disaster with crop failures and famine almost everywhere.

On the SD graph, the Northern Hemisphere temps appear remarkably flat in comparison with those attributed to earlier centuries. Whats up with that?

I don’t see anywhere in the study any claim whatsoever that temps during the MWP were warmer than today.

The contrived disappearance of the MWP isn’t just a discredited Michael Mann talking point; if the MWP occurred, then the entire AGW edifice comes crashing down.

That’s why the alarmists can not admit its existence.

And think of all the moisture released to the atmosphere at this time. I personally believe that many alpine ice sheets are 10k to 12k years old (Kilimanjaro) because they formed when the continental glaciers retreated.

This might be of interest for you!
I have found a similar paper which shows the same thing.
“Century-Scale Mega-Droughts in India During the Holocene”
This paper can be found in this collection:
http://www.mesh.usc.edu/files/HPIM_Research_Summaries.pdf

The data were collected from caves in India. The paper links solar activity to climate variations. This paper also shows that periods of reduction in the monsoon are linked to period with cold climate such as that during the Little Ice Age. This makes the threat of reduced food production not only a threat for lower food production in temperate regions but also a threat for food production in the high population countries of India and China during periods of colder climate.