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
(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
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
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.
- 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
- 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
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.