The real question is what caused the drop in “temperature” from the MWP to the LIA.

I think you are probably right, but if we assume for the sake of argument that it was limited to the Northern Hemisphere, there still remains the question: What (if anything) caused it?

The 5.2 seems to summarize everything Big Picture style whereas the other table seems to break stuff down into data by region/type.

“The processed temperature data is available on-line at:
vortex.nsstc.uah.edu/data/msu/t2lt/uahncdc.lt”

REPLY: Fred just FYI, I’m a bit busy today, I can’t always drop everything to research and answer a question. I hope that others can answer for you.

- Anthony

The only way you can get here is to buy into MBH99 or Ammann and Wahl’s defence against M&M05’s proof of MBH99 being wrong. Otherwise the literature is rife with examples showing that MWP was in fact global.

Given that MBH99 is completely and utterly discredited to the point that even the IPCC on AR4 no longer used the hockey stick, yours seems a very curious and telling comment; it’s as if you start with MBH99 and go from there.

The MWP was global. Period. MBH99 was wrong, and they lied. Period.

PS I would like to see this data set rounded to nearest whole number.

REPLY: Mike eyeballing doesn’t reveal the trends all that well. There is a decadal trend of 0.130 degrees in the global data. – Anthony

http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.2

http://vortex.nsstc.uah.edu/public/msu/t2lt/tltglhmam_5.2

John M Reynolds

Science is not pointless but it has its limits and it is good to recognize those.

I agree, and it’s troubling to me the way people throw around phrases like “chaotic system” without really knowing what they are talking about.

Why is it possible to predict an eclipse? Because a small error in the measurement of the positions and motions of sun, earth, and moon results in only a small error in predicting their positions at or around the time of the next eclipse.

In a chaotic system, these uncertainties have a tendency to multiply, giving results that are difficult or impossible to predict even if one understands the interactions of the system’s elements.

In my opinion, if that poster had meant “unpredictable,” then he or she should have said so. Instead, he or she used the phrase “chaotic systems,” which is not quite the same thing. A chaotic system has the property of being sensitive to initial conditions. Thus it remains unpredictable even if the underlying physical properties of the system are well understood.

In any event, as far as I know, it’s an open question as to whether the climate is chaotic on a 50 to 100 year time frame. If a butterfly can cause a storm, can we rule out the possibility of a butterfly causing a little ice age?

BTW, you might be interested to know that I just added HADSST2 sea surface temperatures…

Cheers

Paul

http://www.longrangeweather.com/global_temperatures.htm

To add to the decrease of incoming radiation, the sun also underwent the “Maunder Minimum.” Although there really isn’t a physical mechanism which has connected sunspots to a cooling sun, it is a highly popular hypothesis, and the LIA and especially its peak minimum highly correlate to the maunder minimum.
So that leaves a correlation to the sun.

I thought chaos theory and quantum theory pretty much told us we would have limits on how far we could predict in the future. Einstein famously said that “God does not play dice with the Universe” but could not prove otherwise.

Science is not pointless but it has its limits and it is good to recognize those.