Talk:Little Ice Age

Rm graph

See MWP. William M. Connolley 09:55:23, 03 September 2005 (UTC).

Discrepancy? re: "Little Ice Age definition". Earth Observatory. http://eobglossary.gsfc.nasa.gov/Library/glossary.php3?xref=Little%20Ice%20Age. Retrieved 2007-08-02.

This article states, in the introductory, first paragraph, "It is generally agreed that there were three minima, beginning about 1650, about 1770, and 1850, each separated by intervals of slight warming." However, the source states, "Little Ice Age[:] A cold period that lasted from about A.D. 1550 to about A.D. 1850 in Europe, North America, and Asia. This period was marked by rapid expansion of mountain glaciers, especially in the Alps, Norway, Ireland, and Alaska. There were three maxima, beginning about 1650, about 1770, and 1850, each separated by slight warming intervals." Notice the difference of "minima" stated in this article versus "maxima" stated in the source. As a layperson and not a scientist, I find this difference quite confusing; I am seeking comments to determine if the three given dates are temperature minima (meaning low temperatures) or maxima (meaning?) P.S. The source should be updated to: http://earthobservatory.nasa.gov/Glossary/?mode=alpha&seg=l&segend=n , if this source will continue to be used.CM2G0005 (talk) 05:45, 26 February 2011 (UTC)

Good catch. However, the source makes sense only if "the mountain glacier expansions" had maxima at those dates since the end of the sentence clearly says that it was warmer between the "maxima's". Q Science (talk) 08:05, 26 February 2011 (UTC)

Types of changes in the sun

We have article on the following:

1. Solar variation: the change in the amount of radiation emitted by the Sun
2. Solar cycle: a periodic change in the amount of irradiation from the sun that is experienced on Earth
   • I had thought that the latter was the right place for information about the 11-year sunspot cycle.

Also, I understand that it is not variations in the amount of sunlight but in the number of sunspots, that (supposedly, but disputedly?) correlates with changes in terrestrial temperature. If there are any peer-reviewed scientific papers about this, we should mention them. Or even if it's in science textbooks or some university science department's website. --Uncle Ed (talk) 19:19, 8 June 2011 (UTC)

• Which brings up the interesting question of the Croll cycles, more commonly known as Milankovitch cycles. I've added a subsection with sources showing how this has effected a cooling trend through the MWP and LIA. . . .dave souza, talk 20:39, 8 June 2011 (UTC)

p.s. Ed adapted the SciAm statement "That, in turn, has led to a cooling rate of roughly 0.2 degrees Celsius per 1,000 years" to give a rate of roughly 0.02 degrees Celsius per century. Dunno if that's right..... dave souza, talk 21:01, 8 June 2011 (UTC)

'tis about the Arctic, i'd be cautious about stating that this is a global rate. --Kim D. Petersen (talk) 02:09, 9 June 2011 (UTC) [add: The SciAm article is referring to this paper. Which says -0.22° ± 0.05°C for the Arctic. --Kim D. Petersen (talk) 02:11, 9 June 2011 (UTC)]

Good point, I've put that in a separate sentence specifically tying it to the Arctic, and have added the clarification that in the very long term the rate would be expected to lead to an ice age. . . dave souza, talk 08:22, 9 June 2011 (UTC)

Ed, I suggest you re-read all three articles. The solar cycle is one type of solar variation. Solar energy output is strongly correlated with sunspot activity (although the causal relationships are not too well understood). During the Maunder Minimum and the Sporer Minimum solar activity (and sunspots, and solar energy output) were low for longer periods of time, quite independently of the 11 year solar cycle. --Stephan Schulz (talk) 21:08, 8 June 2011 (UTC)

Asia?

Any records of strange weather or crop failures in India, China and the Middle East? 188.221.129.72 (talk) 19:54, 17 September 2011 (UTC)

Science News resource, regarding

Columbus' arrival linked to carbon dioxide drop "Depopulation of Americas may have cooled climate" by Devin Powell November 5th, 2011; Vol.180 #10 (p. 12); excerpt ...

The European conquest of the Americas decimated the people living there, leaving large areas of cleared land untended. Trees that filled in this territory pulled billions of tons of carbon dioxide from the atmosphere, Stanford University geochemist Richard Nevle reported October 11 at the Geological Society of America annual meeting. Such carbon dioxide removal could have diminished the heat-trapping capacity of the atmosphere and cooled the climate, Nevil and his colleagues have previously reported.

Example of depopulation described in Guns, Germs, and Steel. 97.87.29.188 (talk) 23:04, 9 November 2011 (UTC)

This possible cause was already discussed in the "Decreased human populations" section of the article, but I added the Science News reference you posted as an additional citation in the section. By the way, the abstract of the actual paper is here: http://gsa.confex.com/gsa/2011AM/finalprogram/abstract_196092.htm Geoffrey.landis (talk) 20:53, 1 February 2012 (UTC)

New study

http://www.colorado.edu/news/releases/2012/01/30/new-cu-led-study-may-answer-long-standing-questions-about-enigmatic-little may be interesting William M. Connolley (talk) 20:11, 1 February 2012 (UTC)

I added references to this study yesterday. Geoffrey.landis (talk) 20:35, 1 February 2012 (UTC)

So you did; thank you. I prefer to leave these things to settle for a little while rather than adding them immeadiately, which is why I dumped it on the talk page to come back to later. But I don't object to you adding this one William M. Connolley (talk) 20:39, 1 February 2012 (UTC)

It seemed relevant. Particularly the dating section is of interest, since apparently the dates of the LIA are not well constrained. Geoffrey.landis (talk) 20:54, 1 February 2012 (UTC)