One of us is wrong, since you claim that it was “warm” during the Spoerer MInimum, and I do not. I don’t base my opinion on Wiki alone, but they often
include references to pertinent articles. And when it is said “The Spörer Minimum has also been identified with a significant cooling period near the beginning of the Little Ice Age” I suspect is supported by some research. For example, Wiki’s entry for “Medieval Warm Period” has a graph taken from
http://www.ncdc.noaa.gov/paleo/globalwarming/medieval.html
showing that around the time of the Spoerer Minimum temps in the NH surface could have approached a degree C below today’s mean.
WIki’s “Little Ice Age” entry has “Other indicators of low solar activity during this period are levels of the isotopes carbon-14 and beryllium-10″ which includes a chart not available for view from the referenced abstract provided
http://www.sciencemag.org/cgi/content/abstract/289/5477/270
but shows several minimas following the Medieval Maximum, then in the last hundred fifty years or so, an increase in solar activity. This in my opinion matches the temperature record in general. And as I have commented elsewhere, a increase in just one or two w/m2 is claimed to be the cause of the increase due to AGW in the last 50 -100 years. Minimas it appears can vary
Earth’s total solar irradiance by at least that much. I don’t think anyone believes things can happen instantly on a global scale, but it sure looks like solar activity has played at least a significant if not major part in the temp of the Earth for the last thousand years.

I suspect you meant to reference Figure 1 instead, although Figure 1 is in contradiction to your other reference: “The results suggested the existence of four cold periods, 1330-1350…” since 1330 is at the top, or warmest period of that chart. Is there something missing that explains this problem?
What is missing is that the borehole reconstruction does not have a time resolution high enough to resolve 20 years, but works ok with periods several times longer.

The “less extreme” is in reference to the subject of temperature, in English.
Take into account that the authors are Japanese. Ever tired to read a user manual for some erectronic device made in Japan?

Actually, no it doesn’t. The figure on your site that matches the article graph is for the last 2000 years:

http://www.geo.lsa.umich.edu/~shaopeng/2008GL034187.pdf

“Figure 2. Same suite of reconstructions as in Figure 1, but
displayed over only the past 2,000 years on an expanded
timescale.”

That graph matches the one on your site exactly.

I suspect you meant to reference Figure 1 instead, although Figure 1 is in contradiction to your other reference: “The results suggested the existence of four cold periods, 1330-1350…” since 1330 is at the top, or warmest period of that chart. Is there something missing that explains this problem?

I found, quite by fortuitous accident, the URL to the first paper you mentioned which you claimed was evidence the LIA didn’t start till 1400 AD:
http://www.geo.lsa.umich.edu/~shaopeng/2008GL034187.pdf

The Spoerer Minimum is said to have occured 1415–1534 AD, but that article does not even mention “Spoerer Minimum”. I fail to see how either article you offer holds evidence that the Spoerer MInimum was a “warm” period.

The authors are correct about their periods in years, but are not correct that the second period 1520-1550 was the Spoerer minimum. I thought we agreed [at least I agreed with your claim] that the Spoerer minimum was a hundred years before that. I’m amazed that you can’t see that, but I guess AGW makes blind for facts :-)

“The results suggested the existence of four cold periods, 1330-1350, 1520-1550, 1670-1700, and 1825-1830, during which periods the estimated March mean temperature was 4-5 °C, about 3-4 °C lower than the present normal temperature. These cold periods coincided with the less extreme periods, known as the Wolf, Spoerer, Maunder, and Dalton minima, in the long-term solar variation cycle, which has a periodicity of 150-250 years.”

In fact, going with your argument, this is contradictory, since the Maunder MInimum does coincide with the 1670-1700 range, yet they include the Maunder as one minimum that is “less extreme”, and the Maunder Minimum
(1645-1715) is another well known cold period, some say the coldest part of the Little Ice age. These authors claim that the Maunder Minimum, like the Spoerer Minimum, were “less extreme” than the periods which they identify as
being colder. Even if that were true and those periods were colder than the periods of the minimas, they do not claim that the periods between are “warm”
in any sense of the word, and the article can not be interpreted as evidence that the Spoerer Minimum was a “warm” period.

Of course as far as I know, we are both going by the article’s abstract. Yet if they had meant the Minima’s were found to be warm, they would not have said
“less extreme”. Less extreme than 3 or 4 C could still be quite cold, as in the middle of the LIA. Danced on the Thames lately? The first “Frost Fair” was in 1607, in one of those “less extreme” periods claimed to occur in Japan at the same time. Not regional? Going to claim that the Maunder MInimum was a warm period too?