|
|
 |
|
|
 |
|
A study by Dana Royer, assistant professor of
earth and environmental sciences, has established a calculable relationship
between increases in CO2
and global surface temperatures. |
|
| Posted 04.02.07 |
Faculty Finds Strongest Evidence Yet of Link Between CO2 and Global
Temperature Change
|
The connection between CO2
concentrations and increased global temperatures just gained a significant
amount of evidence - about 420 million years worth of evidence, to be
specific.
In a paper published in the March 29 issue of Nature, Dana Royer,
assistant professor of earth and environmental sciences, and two colleagues
from Yale University have used nearly 500 data points to create the most
comprehensive model of the relationship between CO2
and temperature to date. The findings indicate that over the last 420
million years increases in CO2
in the atmosphere have had a direct and calculable relationship to increases
in global surface temperatures.
Royer is the study’s primary investigator; his co-authors on the paper are
Robert Berner and Jeffrey Park who are both faculty at the Department of
Geology and Geophysics at Yale University.
The study provides the strongest and most conclusive evidence to date that,
in the history of the Earth, rises in atmospheric CO2
concentrations are directly linked to increases in global surface
temperatures.
“This link has been established by previous studies, but the most expansive
of these only went back about 15,000 years,” Royer says. “That’s barely a
blink of an eye in terms of the life of the planet. Our study went back much
further in time. It was intriguing that much of what we found was consistent
with these other studies.
Specifically, what Royer and his co-investigators found was that every
doubling of atmospheric CO2
concentrations resulted in an approximately 3° C (approx 5 ° F) increase in
global surface temperature. This ratio is consistent with shorter-term
models and surveys.
Of course, identifying accurate data points for atmospheric CO2
are what make studies such as these difficult. Before approximately 50 years
ago, there were no atmospheric CO2
measurements made directly by human beings. However, scientists have been
able to use a variety of methods that rely on studies of soil, sediments,
sea beds, and even fossils.
“One method involves analyzing the stomata of certain kinds of fossilized
plants,” Royer says. “When the CO2
concentrations are higher, plants will have
fewer pores for gas exchange. When it is lower, these plants will have more
pores. This information can be combined with what we know about the
temperature and other environmental factors from that period in a particular
kind of modeling.”
Royer and his fellow researchers were able to draw together the data
generated from a variety of methods to create their study.
|
|
By David Pesci, director of Media Relations |
|
|
 |
|
|
