• ArtsandLectures twitter avatar
    RT @TheBarbBuzz: Arlington Theatre is buzzing again: https://t.co/p85cLiQIjO - RT @ArtsandLectures David Sedaris is bringing stories and la…
    10 hours 56 min ago
  • UCSBgauchos twitter avatar
    Gauchos Battle to Doubleheader Split in Final Home Games of 2016 https://t.co/dG52Hvk7SR
    11 hours 59 min ago
  • ArtsandLectures twitter avatar
    RT @randomhouse: In Santa Barbara? Come see Jill Leovy and David Sedaris at UCSB @ArtsandLectures TOMORROW at 7PM.
    12 hours 47 min ago
  • ArtsandLectures twitter avatar
    RT @grupocorpo: #video da turne nos Estados Unidos - ep 2 | @ArtsandLectures @whitebirddance #grupocorpo #USAtour https://t.co/8qEXvAZLFk
    12 hours 47 min ago
  • ArtsandLectures twitter avatar
    David Sedaris is bringing stories and laughs to the Arlington Theatre on Sunday at 7. @ArtsandLectures #funnyman #ThisAmericanLife
    12 hours 56 min ago
  • UCSBgauchos twitter avatar
    Grover's blast gives @UCSB_Baseball its 15th straight home W, a new program record! RECAP >> https://t.co/LkmDfIw4p0 https://t.co/sTMUGB582j
    13 hours 15 min ago
  • UCSBgauchos twitter avatar
    Murphy's Golden Goal Sends No. 9 UCSB to Championship Game! https://t.co/jcuBJ59FGQ
    13 hours 46 min ago
  • ucsantabarbara twitter avatar
    #UCSB students develop skills while producing deliverables that solve environmental problems for real-world clients. https://t.co/txhMIVw3Hr
    20 hours 57 min ago
  • UCSBgauchos twitter avatar
    Palomares's RBI Doubles Power UCSB to 9-3 Win Over Hawai'i https://t.co/X9BzJu0sVy
    1 day 11 hours ago
  • ucsantabarbara twitter avatar
    Check out the 10th All Gaucho Reunion Weekend and celebrate with fellow UCSB alumni, students and community friends! https://t.co/fOe2QqNgaq
    1 day 12 hours ago
  • UCSBgauchos twitter avatar
    @UCSB_Baseball hammers Hawaii, ties prog record w/ 14 straight home Ws. RECAP >> https://t.co/dZLUAGCjep https://t.co/b6GEA284lq
    1 day 12 hours ago
  • UCSBgauchos twitter avatar
    Murphy's Hat Trick Leads No. 9 Gauchos Past CSUN in Big West Tournament 1st Round, 8-4 https://t.co/141ORa3LDS
    1 day 14 hours ago

Link Between Tropical Warming and Greenhouse Gases Stronger Than Ever, Say Scientists

Thursday, October 13, 2005 - 17:00
Santa Barbara, CA

New evidence from climate records of the past provides some of the strongest indications yet of a direct link between tropical warmth and higher greenhouse gas levels, say scientists at the University of California, Santa Barbara. The present steady rise in tropical temperatures due to global warming will have a major impact on global climate and could intensify destructive hurricanes like Katrina and Rita.

The new evidence linking past tropical ocean temperatures to levels of atmospheric greenhouse gases is published in this week's Science Express, the on-line publication of the journal Science. The authors are Martin Medina-Elizalde, graduate student in the Department of Earth Science and the Interdepartmental Program in Marine Science at UC Santa Barbara, and David Lea, professor in UCSB's Department of Earth Science and the Marine Science Institute.

The link between increased atmospheric greenhouse gas and global temperatures underlies the theory of global warming, explained the authors. This link can be established by computer climate models or modern observations. Another way to study the link is through paleoclimate observations where past climate is reconstructed through natural archives. This latest study is based on such paleoclimate observations; the scientists analyzed the chemical composition of fossil plankton shells from a deep sea core in the equatorial Pacific.

"The relationship between tropical climate and greenhouse gases is particularly critical because tropical regions receive the highest proportion of solar output and act as a heat engine for the rest of the earth," said Lea.

Modern observations of tropical sea surface temperature indicate a rise of one to two degrees Fahrenheit over the last 50 years, a trend consistent with rising carbon dioxide in the atmosphere due to fossil fuel combustion, according to the authors. The paleoclimate evidence from this new study supports the attribution of the tropical temperature trend to the ever-increasing greenhouse gas burden in the atmosphere.

The research described in this week's article demonstrates that over the last 1.3 million years, sea surface temperatures in the heart of the western tropical Pacific were controlled by the waxing and waning of the atmospheric greenhouse effect. The largest climate mode shift over this time interval, occurring ~950,000 years before the present (the mid-Pleistocene transition), has previously been attributed to changes in the pattern and frequency of ice sheets.

The new research suggests instead that this shift is due to a change in the oscillation frequency of atmospheric carbon dioxide abundances, a hypothesis that can be directly tested by deep drilling on the Antarctic Ice Cap. If proved correct, this theory would suggest that relatively small, naturally occurring fluctuations in greenhouse gases are the master variable that has driven global climate change on time scales of ten thousand to one million years.

 

###

 

† About the Illustration

This live plankton, called foraminifera, can indicate ocean temperature through analysis of its chemical composition. The paleoclimate observations in the Science Express paper come from analysis of foraminifera fossils, from a deep sea core in the equatorial Pacific. Photo credit: H. Spero, UC Davis and D. Lea, UC Santa Barbara.

David Lea's Web Site