[Vision2020] Science Journal Online Oct. 2009: CO2 at Highest Levels in 15 Million Years

[Ted Moffett]

UCLA Researcher Finds CO2 at Highest Levels in 15 Million Years

http://www.sustain.ucla.edu/news/article.asp?parentid=4676

Article from website above appears in total at bottom of this post,
below the Science Journal abstract for the paper referenced.
--------------------------

Note that the important scientific findings presented in the paper
referenced in the subject heading, that should have received
widespread front page media coverage but did not, were released close
to the time of the 2009 Copenhagen Climate Change Conference.

Yet major media at that time were giving widespread coverage to the
Climatic Research Unit hacked emails of East Anglia University in the
United Kingdom, suggesting to the public widespread fraud or
incompetence in climate science.  Also not given widespread front page
coverage was the 2009 MIT Integrated Global Systems Model results,
indicating "New analysis shows warming could be double previous
estimates:"
http://web.mit.edu/newsoffice/2009/roulette-0519.html

Public science education in the US lags many other nations, and it is
not schools and parents that are only to blame.  Our profit driven
large coporate owned media does not responsibly present important
scientific findings that are critical for public education and
decision making, such as on the science regarding anthropogenic
climate warming, a major failure of the Fourth Estate:

http://www.sciencemag.org/content/326/5958/1394.abstract

Published Online 8 October 2009
Science 4 December 2009:
Vol. 326 no. 5958 pp. 1394-1397
DOI: 10.1126/science.1178296

Report

Coupling of CO2 and Ice Sheet Stability Over Major Climate Transitions
of the Last 20 Million Years

Aradhna K. Tripati1,2,*, Christopher D. Roberts2 and Robert A. Eagle3

Abstract

The carbon dioxide (CO2) content of the atmosphere has varied
cyclically between ~180 and ~280 parts per million by volume over the
past 800,000 years, closely coupled with temperature and sea level.
For earlier periods in Earth’s history, the partial pressure of CO2
(pCO2) is much less certain, and the relation between pCO2 and climate
remains poorly constrained. We use boron/calcium ratios in
foraminifera to estimate pCO2 during major climate transitions of the
past 20 million years. During the Middle Miocene, when temperatures
were ~3° to 6°C warmer and sea level was 25 to 40 meters higher than
at present, pCO2 appears to have been similar to modern levels.
Decreases in pCO2 were apparently synchronous with major episodes of
glacial expansion during the Middle Miocene (~14 to 10 million years
ago) and Late Pliocene (~3.3 to 2.4 million years ago
---------------------------------
News release regarding Science Journal paper abstract above:

http://www.sustain.ucla.edu/news/article.asp?parentid=4676

UCLA Researcher Finds CO2 at Highest Levels in 15 Million Years

You would have to go back at least 15 million years to find carbon
dioxide levels on Earth as high as they are today, UCLA chemist
Aradhna Tripati and colleagues report Oct. 8 in the online edition of
the journal Science.

"The last time carbon dioxide levels were apparently as high as they
are today... global temperatures were 5 to 10 degrees Fahrenheit
higher than they are today, the sea level was approximately 75 to 120
feet higher than today"Original article from the UCLA Newsroom:

Last time carbon dioxide levels were this high: 15 million years ago,
scientists report
By Stuart Wolpert October 08, 2009
You would have to go back at least 15 million years to find carbon
dioxide levels on Earth as high as they are today, a UCLA scientist
and colleagues report Oct. 8 in the online edition of the journal
Science.

"The last time carbon dioxide levels were apparently as high as they
are today — and were sustained at those levels — global temperatures
were 5 to 10 degrees Fahrenheit higher than they are today, the sea
level was approximately 75 to 120 feet higher than today, there was no
permanent sea ice cap in the Arctic and very little ice on Antarctica
and Greenland," said the paper's lead author, Aradhna Tripati, a UCLA
assistant professor in the department of Earth and space sciences and
the department of atmospheric and oceanic sciences.

"Carbon dioxide is a potent greenhouse gas, and geological
observations that we now have for the last 20 million years lend
strong support to the idea that carbon dioxide is an important agent
for driving climate change throughout Earth's history," she said.

By analyzing the chemistry of bubbles of ancient air trapped in
Antarctic ice, scientists have been able to determine the composition
of Earth's atmosphere going back as far as 800,000 years, and they
have developed a good understanding of how carbon dioxide levels have
varied in the atmosphere since that time. But there has been little
agreement before this study on how to reconstruct carbon dioxide
levels prior to 800,000 years ago.

Tripati, before joining UCLA's faculty, was part of a research team at
England's University of Cambridge that developed a new technique to
assess carbon dioxide levels in the much more distant past — by
studying the ratio of the chemical element boron to calcium in the
shells of ancient single-celled marine algae. Tripati has now used
this method to determine the amount of carbon dioxide in Earth's
atmosphere as far back as 20 million years ago.

"We are able, for the first time, to accurately reproduce the ice-core
record for the last 800,000 years — the record of atmospheric C02
based on measurements of carbon dioxide in gas bubbles in ice,"
Tripati said. "This suggests that the technique we are using is valid.

"We then applied this technique to study the history of carbon dioxide
from 800,000 years ago to 20 million years ago," she said. "We report
evidence for a very close coupling between carbon dioxide levels and
climate. When there is evidence for the growth of a large ice sheet on
Antarctica or on Greenland or the growth of sea ice in the Arctic
Ocean, we see evidence for a dramatic change in carbon dioxide levels
over the last 20 million years.

"A slightly shocking finding," Tripati said, "is that the only time in
the last 20 million years that we find evidence for carbon dioxide
levels similar to the modern level of 387 parts per million was 15 to
20 million years ago, when the planet was dramatically different."

Levels of carbon dioxide have varied only between 180 and 300 parts
per million over the last 800,000 years — until recent decades, said
Tripati, who is also a member of UCLA's Institute of Geophysics and
Planetary Physics. It has been known that modern-day levels of carbon
dioxide are unprecedented over the last 800,000 years, but the finding
that modern levels have not been reached in the last 15 million years
is new.

Prior to the Industrial Revolution of the late 19th and early 20th
centuries, the carbon dioxide level was about 280 parts per million,
Tripati said. That figure had changed very little over the previous
1,000 years. But since the Industrial Revolution, the carbon dioxide
level has been rising and is likely to soar unless action is taken to
reverse the trend, Tripati said.

"During the Middle Miocene (the time period approximately 14 to 20
million years ago), carbon dioxide levels were sustained at about 400
parts per million, which is about where we are today," Tripati said.
"Globally, temperatures were 5 to 10 degrees Fahrenheit warmer, a huge
amount."

Tripati's new chemical technique has an average uncertainty rate of
only 14 parts per million.

"We can now have confidence in making statements about how carbon
dioxide has varied throughout history," Tripati said.

In the last 20 million years, key features of the climate record
include the sudden appearance of ice on Antarctica about 14 million
years ago and a rise in sea level of approximately 75 to 120 feet.

"We have shown that this dramatic rise in sea level is associated with
an increase in carbon dioxide levels of about 100 parts per million, a
huge change," Tripati said. "This record is the first evidence that
carbon dioxide may be linked with environmental changes, such as
changes in the terrestrial ecosystem, distribution of ice, sea level
and monsoon intensity."

Today, the Arctic Ocean is covered with frozen ice all year long, an
ice cap that has been there for about 14 million years.

"Prior to that, there was no permanent sea ice cap in the Arctic," Tripati said.

Some projections show carbon dioxide levels rising as high as 600 or
even 900 parts per million in the next century if no action is taken
to reduce carbon dioxide, Tripati said. Such levels may have been
reached on Earth 50 million years ago or earlier, said Tripati, who is
working to push her data back much farther than 20 million years and
to study the last 20 million years in detail.

More than 50 million years ago, there were no ice sheets on Earth, and
there were expanded deserts in the subtropics, Tripati noted. The
planet was radically different.

Co-authors on the Science paper are Christopher Roberts, a Ph.D.
student in the department of Earth sciences at the University of
Cambridge, and Robert Eagle, a postdoctoral scholar in the division of
geological and planetary sciences at the California Institute of
Technology.

The research was funded by UCLA's Division of Physical Sciences and
the United Kingdom's National Environmental Research Council.

Tripati's research focuses on the development and application of
chemical tools to study climate change throughout history. She studies
the evolution of climate and seawater chemistry through time.

"I'm interested in understanding how the carbon cycle and climate have
been coupled, and why they have been coupled, over a range of
time-scales, from hundreds of years to tens of millions of years,"
Tripati said.

In addition to being published on the Science Express website, the
paper will be published in the print edition of Science at a later
date.

The Original Article in Science Express

Coverage in Time magazine

Date Posted: 10/9/2009

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Vision2020 Post: Ted Moffett