Hydrologic impacts of past shifts of Earth's thermal equator offer insight into those to be produced by fossil fuel CO2

Major changes in global rainfall patterns accompanied a northward shift of Earth's thermal equator at the onset of an abrupt climate change 14.6 kya. This northward pull of Earth's wind and rain belts stemmed from disintegration of North Atlantic winter sea ice cover, which steepened the i...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2013-10, Vol.110 (42), p.16710-16715
Main Authors: Broecker, Wallace S., Putnam, Aaron E.
Format: Article
Language:English
Subjects:
Carbon Dioxide
Climate Change
Climate models
Fossil Fuels
Glacial ages
Global warming
Hydrology
Lakes
Models, Theoretical
Monsoons
Oceans
Oceans and Seas
Paleoclimatology
PERSPECTIVE
Physical Sciences
Sea ice
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Major changes in global rainfall patterns accompanied a northward shift of Earth's thermal equator at the onset of an abrupt climate change 14.6 kya. This northward pull of Earth's wind and rain belts stemmed from disintegration of North Atlantic winter sea ice cover, which steepened the interhemispheric meridional temperature gradient. A southward migration of Earth's thermal equator may have accompanied the more recent Medieval Warm to Little Ice Age climate transition in the Northern Hemisphere. As fossil fuel CO2 warms the planet, the continents of the Northern Hemisphere are expected to warm faster than the Southern Hemisphere oceans. Therefore, we predict that a northward shift of Earth's thermal equator, initiated by an increased interhemispheric temperature contrast, may well produce hydrologic changes similar to those that occurred during past Northern Hemisphere warm periods. If so, the American West, the Middle East, and southern Amazonia will become drier, and monsoonal Asia, Venezuela, and equatorial Africa will become wetter. Additional paleoclimate data should be acquired and model simulations should be conducted to evaluate the reliability of this analog.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.1301855110