Little Ice Age

For the most recent period that was much colder than present with significant glaciation, see Last Glacial Period.

Global average temperatures show that the Little Ice Age was not a distinct planet-wide period but a regional phenomenon occurring near the end of a long temperature decline that preceded recent global warming.[1]

The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region.[2] It was not a true ice age of global extent.[3] The term was introduced into scientific literature by François E. Matthes in 1939.[4] The period has been conventionally defined as extending from the 16th to the 19th centuries,[5][6][7] but some experts prefer an alternative time-span from about 1300[8] to about 1850.[9][10][11]

The NASA Earth Observatory notes three particularly cold intervals. One began about 1650, another about 1770, and the last in 1850, all of which were separated by intervals of slight warming.[7] The Intergovernmental Panel on Climate Change Third Assessment Report considered that the timing and the areas affected by the LIA suggested largely independent regional climate changes, rather than a globally synchronous increased glaciation. At most, there was modest cooling of the Northern Hemisphere during the period.[3]

Several causes have been proposed: cyclical lows in solar radiation, heightened volcanic activity, changes in the ocean circulation, variations in Earth's orbit and axial tilt (orbital forcing), inherent variability in global climate, and decreases in the human population (such as from the massacres by Genghis Khan, the Black Death and the epidemics emerging in the Americas upon European contact[12][13]).

  1. ^ Hawkins, Ed (30 January 2020). "2019 years". climate-lab-book.ac.uk. Archived from the original on 2 February 2020. "The data show that the modern period is very different to what occurred in the past. The often quoted Medieval Warm Period and Little Ice Age are real phenomena, but small compared to the recent changes."
  2. ^ Ladurie, Emmanuel Le Roy (1971). Times of Feast, Times of Famine: a History of Climate Since the Year 1000. Barbara Bray. Garden City, New York: Doubleday. ISBN 978-0-374-52122-6. OCLC 164590.
  3. ^ a b "Climate Change 2001: The Scientific Basis". UNEP/GRID-Arendal. Archived from the original on 29 May 2006. Retrieved 2 August 2007.
  4. ^ Matthes, François E. (1939). "Report of Committee on Glaciers, April 1939". Transactions, American Geophysical Union. 20 (4): 518–523. Bibcode:1939TrAGU..20..518M. doi:10.1029/TR020i004p00518. Matthes described glaciers in the Sierra Nevada of California that he believed could not have survived the hypsithermal; his usage of "Little Ice Age" has been superseded by "Neoglaciation".
  5. ^ Mann, Michael (2003). "Little Ice Age" (PDF). In MacCracken, Michael C.; Perry, John S. (eds.). Encyclopedia of Global Environmental Change, The Earth System: Physical and Chemical Dimensions of Global Environmental Change. Vol. 1. John Wiley & Sons. Archived (PDF) from the original on 9 October 2022. Retrieved 17 November 2012.
  6. ^ Lamb, H. H. (1972). "The cold Little Ice Age climate of about 1550 to 1800". Climate: present, past and future. London, England: Methuen. p. 107. CiteSeerX 10.1.1.408.1689. ISBN 978-0-416-11530-7. (noted in Grove 2004: 4).
  7. ^ a b "Earth observatory Glossary L–N". NASA Goddard Space Flight Center, Green Belt, Maryland: NASA. Retrieved 17 July 2015.
  8. ^ Cite error: The named reference miller2012 was invoked but never defined (see the help page).
  9. ^ Grove, J. M., Little Ice Ages: Ancient and Modern, Routledge, London, England (2 volumes) 2004.
  10. ^ Matthews, John A.; Briffa, Keith R. (2005). "The 'little ice age': Re-evaluation of an evolving concept". Geografiska Annaler: Series A, Physical Geography. 87 (1): 17–36. Bibcode:2005GeAnA..87...17M. doi:10.1111/j.0435-3676.2005.00242.x. S2CID 4832081.
  11. ^ "1.4.3 Solar Variability and the Total Solar Irradiance – AR4 WGI Chapter 1: Historical Overview of Climate Change Science". Ipcc.ch. Retrieved 24 June 2013.
  12. ^ Koch, Alexander; Brierley, Chris; Maslin, Mark M.; Lewis, Simon L. (1 March 2019). "Earth system impacts of the European arrival and Great Dying in the Americas after 1492". Quaternary Science Reviews. 207: 13–36. Bibcode:2019QSRv..207...13K. doi:10.1016/j.quascirev.2018.12.004.
  13. ^ "How Genghis Khan cooled the planet". Mongabay Environmental News. 20 January 2011.