File:Five Myr Climate Change Rev.png

From Global Warming Art

Description

Expansion of changes during the recent sequence of glacials and interglacials.
Climate change during the last 65 million years

This figure shows the climate record of Lisiecki and Raymo (2005) [1] constructed by combining measurements from 57 globally distributed deep sea sediment cores. The measured quantity is oxygen isotope fractionation in benthic foraminifera, which serves as a proxy for the total global mass of glacial ice sheets.

Lisiecki and Raymo constructed this record by first applying a computer aided process of adjusting individual "wiggles" in each sediment core to have the same alignment (i.e. wiggle matching). Then the resulting stacked record is orbitally tuned by adjusting the positions of peaks and valleys to fall at times consistent with an orbitally driven ice model (see: Milankovitch cycles). Both sets of these adjustments are constrained to be within known uncertainties on sedimentation rates and consistent with independently dated tie points (if any). Constructions of this kind are common, however they presume that ice sheets are orbitally driven, and hence data such as this can not be used in establishing the existence of such a relationship.

The observed isotope variations are very similar in shape to the temperature variations recorded at Vostok, Antarctica during the 420 kyr for which that record exists. Hence the right hand scale of the figure was established by fitting the reported temperature variations at Vostok (Petit et al. 1999) to the observed isotope variations. As a result, this temperature scale should be regarded as approximate and its magnitude is only representative of Vostok changes. In particular, temperature changes at polar sites, such as Vostok, frequently exceed the changes observed in the tropics or in the global average. A horizontal line at 0 °C indicates modern temperatures (circa 1950).

Labels are added to indicate regions where 100 kyr and 41 kyr cyclicity is observed. These periodicities match periodic changes in Earth's orbital eccentricity and obliquity respectively, and have been previously established by other studies (not relying on orbital tuning). For discussion of how such orbital changes might drive climate change, see Milankovitch cycles.


Temperature Record Series
This figure is part of series of plots showing changes in Earth's temperature over time.
Time Period: 25 yrs | 150 yrs | 1 kyr | 2 kyr | 12 kyr | 450 kyr | 5 Myr | 65 Myr | 500 Myr
See also: Future predicted changes | Map of recent warming | Temperature change category

Copyright

This figure was prepared by Robert A. Rohde based on published data.


float
Global Warming Art License

This image is an original work created for Global Warming Art by Robert A. Rohde.

It is intended to be widely used, but the terms of use vary depending on the application.
Please select the category below that best matches your intended use.


It is also requested, but not required, that authors send Global Warming Art a copy of any significant publications that include the use of this image. Those interested in commercial and/or higher quality reproduction may also wish to refer to the information for professional republishers.


References

  • [abstract] [full text] [DOI] Lisiecki, L. E., and M. E. Raymo (2005). "A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records". Paleoceanography 20: PA1003. 
  • [abstract] [DOI] Petit J.R., Jouzel J., Raynaud D., Barkov N.I., Barnola J.M., Basile I., Bender M., Chappellaz J., Davis J., Delaygue G., Delmotte M., Kotlyakov V.M., Legrand M., Lipenkov V., Lorius C., Pépin L., Ritz C., Saltzman E., Stievenard M. (1999). "Climate and Atmospheric History of the Past 420,000 years from the Vostok Ice Core, Antarctica". Nature 399: 429-436. 

There are no pages that link to this file.

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current05:25, 2 April 2007Thumbnail for version as of 05:25, 2 April 2007800×242 (24 KB)Robert A. Rohde (Talk | contribs) (label fix)
03:18, 20 February 2006Thumbnail for version as of 03:18, 20 February 2006750×227 (22 KB)Robert A. Rohde (Talk | contribs)

    Random image
    This is a cached copy of the requested page, and may not be up to date.

    Sorry! This site is experiencing technical difficulties.
    Try waiting a few minutes and reloading.

    (Cannot contact the database server: Can't connect to local MySQL server through socket '/mysql/mysql.sock' (2) (localhost))


    You can try searching via Google in the meantime.
    Note that their indexes of our content may be out of date.