University recently conducted a study that
shows a minimal number of scientists who do not accept that human
beings have contributed to the Earth's climate change have "far
less expertise and prominence in climate research" than
scientists who do believe climate change has been affected by
university came to these
conclusions by analyzing the number of research papers
published "by more than 900 climate researchers" and the
number of times these researchers' works were cited by other
scientists. The expertise was evaluated by citing the number of
research papers written by scientists (with the minimum number for
inclusion being 20).
was analyzed by finding the four most popular climate change and
non-climate change papers published by scientists, and "tallying"
the number of times these papers were cited. According to the
results, approximately 64 percent of papers by climate researchers
of human contribution were cited more often than those who
are standard academic metrics used when universities are making
hiring or tenure decisions," said William Anderegg, lead author
of a paper published in Proceedings
of the National Academy of Sciences.
scientists who participated in the study were also involved in
creating the 2007 report of the Intergovernmental
Panel on Climate Change (IPCC), which compiled and "assessed
the evidence for and against human involvement in climate change, as
well as any climate researchers who signed a major public statement
disagreeing with the findings of the panel's report."
addition, the university's team of scientists decided on who the top
100 climate researchers are by determining the "total number of
climate-related publications each had." According to Anderegg,
97 percent of those in the top 100 agree with and/or endorse the
IPCC's assessment. He also says that this result has been "borne
out" by other studies that use different methodology.
really wanted to bring the expertise dimension into this whole
discussion," said Anderegg. "We hope to put to rest the
notion that keeps being repeated in the media and by some members of
the public that 'the scientists disagree' about whether human
activity is contributing to climate change."
scientists at Stanford have mentioned that they are ready to take
some heat from doubters of anthropogenic, or human-affected, climate
change who "object to their data." But according to Stephen
Schneider, a professor of biology and a coauthor of the paper
of the National Academy of Sciences, the
team "took pains to avoid any sort of prejudice or skewed data
in their analysis." When selecting researchers for the study who
with statements of the IPCC or signed the petitions, the
Stanford team was sure to stay completely neutral in the study by
omitting "those who had no published papers in the climate
says that despite the careful analysis of this study, skeptics of
human-affected climate change will "claim foul" anyway, and
will say that climate researchers who are onboard with the idea of
anthropogenic climate change are "just trying to deny
publication of the doubters' opinion," but he challenges them to
"go out and do a study to prove it -- it is of course not true."
think the most typical criticism of a paper like this -- not
necessarily in academic discourse, but in the broader context -- is
going to be that we haven't addressed these sorts of differences
could be due to some clique or, at the extreme, a conspiracy of the
researchers who are convinced of climate change," Anderegg
you stop to consider whether some sort of 'group think' really
patterns and it could really exist in science in general,
the idea is really pretty laughable," he said. "All of the
incentives in science are exactly the opposite."
Stanford study is the first of its kind to address the issue of
scientists' opinions of human-affected climate change, and what their
level of expertise and prominence in the field is.
quote: Changes in the Sun's brightness over the past millennium have had only a small effect on Earth's climate, according to a review of existing results and new calculations performed by researchers in the United States, Switzerland, and Germany.
quote: Warming by the Sun and other variations in natural systems cannot explain global warming... The simulations that include only natural variability, including changes in the Sun and eruptions of volcanoes, show that we should have seen a decrease in the global average temperature in the last several decades.The simulations that most closely resemble the observed record are the ones that take the cooling effect of air pollution and the warming effect of greenhouse gases into account.
quote: According to Shindell, the new study also confirms that changing levels of energy from the sun are not a major cause of global warming.Many scientists have argued that the radiation change in a solar cycle — an increase of two to three tenths of a percent over the 20th century — are not strong enough to account for the observed surface temperature increases. The GISS model agrees that the solar increases do not have the ability to cause large global temperature increases, leading Shindell to conclude that greenhouse gasses are indeed playing the dominant role.