The Little Ice Age

The Medieval Warm Period and the Little Ice Age are significant climate changes that occurred in Europe. (There is significant debate on whether these were "global" or not.)

So, what does this have to do with Global Warming?

It shows the "normal" temperature variation
It proves that the current temperatures can be reached without invoking pollution
It proves that significant warming will not cause a significant sea level rise

Little Ice Age

The Little Ice Age refers to the cooling of Europe in the 1600's - Even though there is considerable debate over when it started and ended and how cold it really was, any Global Warming data that omits this period of time should be rejected out of hand as being obviously biased.

This CDC graph (reiter figure 1) indicates that the Little Ice Age was from 1300 till sometime after 2010 (the graph actually ends about 1930) with 1650 being close to the coldest. But, since it is a graph - you pick the dates.

One of the reasons that I trust this data is that it is published on a government web site discussing diseases and climate ... not a site arguing that humans are destroying the planet via Global Warming.

Though the details are disputed, the graph shows

That the global temperature is not constant
That significant temperature excursions are, in fact, normal
That reports that omit this data are intentionally trying to mislead you

Wikipedia Charts

It is difficult to know what the past temperatures were - the thermometer is a recent invention and it isn't even used in modern temperature estimates (because it measures only the local temperature). Modern "measurements" are taken with satellites.

(I put "measurements" in quotes because the satellite technique is still being calibrated.)

As a result, it is extremely difficult to estimate the temperature for the past. These are some of the proxies used

Tree rings: These are used to determine C-14 variability, amount of water available, and temperature
Ice cores: These have layers similar to the tree rings, changes in thickness indicate the amount of snow
Foraminifera: Very small shells found in sea bed cores
Historical records: Snow staying on the ground until June, years with no snow, floods, and the like
Recorded Temperatures: The temperature of London is not representative of the global average, but annual variations are a reasonable proxy for global changes

The Wikipedia provides 9 temperature charts - each covering a different length of time - and most showing data from several sources ... proving that all scientists do NOT agree on the details. Select one of these and scroll down to get links to the rest.

1000 Year Temperature Comparison shows 10 different reconstructions of past temperature data.
(Please note that this data does not agree with CDC plot.)
Holocene Temperature Variations - the last 12,000 years (note that the most recent data is on the left). One interpretation is that we are currently 2F cooler than about 5,000 years ago.
Five Myr Climate Change - This shows that the Earth has cooled about 10c (18F) in the last 5 million years.

At least my site tries to show a variety of data so that you can understand the argument.

The fact that ocean core data and land records do not agree does NOT prove that the Little Ice Age did not occur (there is way too much data to conclude that). Instead, a better conclusion is that the oceanic foraminifera cores (used as proxies for determining yearly global temperature) do not record what we think they do.

Since they do not record global temperature, they should not be used to change the way we live ... but it is worth additional funding to determine what they do record.

Author: Robert Clemenzi