Transcript Statements on Global Climate Change From Respected Scientific Institutions Crispin H. Pierce, Ph.D. February 2006

Statements on Global Climate
Change From Respected
Scientific Institutions
Crispin H. Pierce, Ph.D.
February 2006
Preface
• The role of health scientists is to provide
objective information (risk assessment) upon
which public health decisions (risk management)
can be made.
• This document is intended to share the findings
of respected scientific institutions on three
questions: 1) Is global warming occurring? 2)
Are human activities a major cause? and 3) Is
this a serious human health threat?
• The list of institutions was subjectively
determined on the basis of consistent, objective
reporting of scientific findings by the author, who
has 33 years of education, research and
experience in environmental public health.
• Institutions were first chosen, then position
statements from each institution were sought.
• The National Oceanic and Atmospheric
Administration, and National Aeronautics and
Space Administration were not chosen due to
recent evidence that information from these
institutions has been politically shaped.
List of Institutions
• National Academy of Sciences
• American Association for the Advancement of Science /
Science
• American Chemical Society / Chemical and Engineering
News
• American Geophysical Union
• Intergovernmental Panel on Climate Change
• US National Research Council
• Journal of the American Medical Association
• US Environmental Protection Agency
• World Health Organization
• Woods Hole Research Center
National Academy of Sciences
“Climate change is real. There will always be uncertainty
in understanding a system as complex as the world’s
climate. However there is nowstrong evidence that
significant global warming is occurring. The evidence
comes from direct measurements of rising surface air
temperatures and subsurface ocean temperatures and
from phenomena such as increases in average global
sea levels, retreating glaciers, and changes to many
physical and biological systems. It is likely that most of
the warming in recent decades can be attributed to
human activities. This warming has already led to
changes in the Earth's climate.”
American Association for the
Advancement of Science
• “As we add greenhouse gases like carbon dioxide and
methane to the atmosphere, they form a blanket that
intercepts infrared radiation as it leaves Earth. This
"greenhouse effect" has been well understood for more
than a century. Models that have tracked average global
temperature over its fluctuations during the past 10
centuries show that it has followed natural events (such
as volcanic eruptions and variations in solar flux) quite
well up until the 20th century. Then it entered a rapidly
rising phase, associated with an increase in atmospheric
carbon dioxide from its preindustrial level of 280 parts
per million (ppm) to the present level of 380 ppm--a
value still accelerating as we continue business as usual.
That's why the Intergovernmental Panel on Climate
Change now attributes much of the present warming
trend to human activity.” Editor-in-chief Donald Kennedy,
Science
American Chemical Society
• “The NASA scientists also maintain that the link
between the record temperatures and human
activities is clear. ‘Recent warming coincides
with rapid growth of human-made greenhouse
gases,’ they write. ‘Climate models show that the
rate of warming is consistent with expectations.
The observed rapid warming thus gives urgency
to discussions about how to slow greenhouse
gas emissions.’ Rudy Baum, Editor-in-chief,
Chemical and Engineering News
American Geophysical Union
• “Human activities are increasingly altering
the Earth's climate. These effects add to
natural influences that have been present
over Earth's history. Scientific evidence
strongly indicates that natural influences
cannot explain the rapid increase in global
near-surface temperatures observed
during the second half of the 20th century.”
Intergovernmental Panel on
Climate Change
• “An increasing body of observations gives
a collective picture of a warming world and
other changes in the climate system.”
• “The global average surface
temperature has increased over the
20th century by about 0.6°C.”
• “Temperatures have risen during the past
four decades in the lowest 8 kilometres of
the atmosphere.”
• “Snow cover and ice extent have decreased.”
• “Global average sea level has risen and
ocean heat content has increased.”
• “Some important aspects of climate appear not
to have changed.”
• “Emissions of greenhouse gases and aerosols
due to human activities continue to alter the
atmosphere in ways that are expected to affect
the climate.”
• “Concentrations of atmospheric greenhouse
gases and their radiative forcing have continued
to increase as a result of human activities.”
• “Natural factors have made small contributions
to radiative forcing over the past century.”
• “There is new and stronger evidence that most
of the warming observed over the last 50 years
is attributable to human activities.”
• “Anthropogenic climate change will persist
for many centuries.”
US National Research Council
• “Greenhouse gases are accumulating in Earth's
atmosphere as a result of human activities,
causing surface air temperatures and
subsurface ocean temperatures to rise.
Temperatures are, in fact, rising. The changes
observed over the last several decades are
likely mostly due to human activities, but we
cannot rule out that some significant part of
these changes is also a reflection of natural
variability. Human-induced warming and
associated sea level rises are expected to
continue through the 21st century.”
• “The IPCC's conclusion that most of the
observed warming of the last 50 years is
likely to have been due to the increase in
greenhouse gas concentrations accurately
reflects the current thinking of the scientific
community on this issue.”
Journal of the American Medical
Association
• “This issue of MSJAMA brings together several lines of
published evidence that global warming has emerged as
a public health challenge requiring serious, concerted
action. Jonathan Patz and Mahmooda Khaliq survey the
immediate threats posed by climate change as well as
some of the more insidious ones. Kent Bransford and
Janet Lai find grounds for a common approach to both
climate change and air pollution. Stephen Liang and
colleagues describe technologies that can help track the
spread of climate-sensitive infectious disease vectors.
Finally, William Burns discusses public policy tools to
respond and adapt to these challenges.”
• “…it is not too late and none too soon for the health care
community to advocate policies that wean us from fossil
fuels and ultimately mitigate the extent of humaninduced climate change.” John F. Staropoli
US Environmental Protection
Agency
• “Scientists know for certain that human
activities are changing the composition of
Earth's atmosphere. Increasing levels of
greenhouse gases, like carbon dioxide
(CO2 ), in the atmosphere since preindustrial times have been well
documented. There is no doubt this
atmospheric buildup of carbon dioxide and
other greenhouse gases is largely the
result of human activities.”
• “It's well accepted by scientists that
greenhouse gases trap heat in the Earth's
atmosphere and tend to warm the planet.
By increasing the levels of greenhouse
gases in the atmosphere, human activities
are strengthening Earth's natural
greenhouse effect. The key greenhouse
gases emitted by human activities remain
in the atmosphere for periods ranging from
decades to centuries.”
• “A warming trend of about 1°F has been
recorded since the late 19th century.
Warming has occurred in both the northern
and southern hemispheres, and over the
oceans. Confirmation of 20th-century
global warming is further substantiated by
melting glaciers, decreased snow cover in
the northern hemisphere and even
warming below ground.”
World Health Organization
• “Global warming is one of the most serious
threats to our environment.”
Woods Hole Research Center
• “…it is certain that we have been
experiencing increasing numbers of
climatic events unprecedented in the
human experience. It is also certain that
many of the greenhouse gases, including
carbon dioxide and methane, have lengthy
residence times in the atmosphere and
that we will continue to be affected for
years or even centuries to come by the
atmospheric burden we are creating
today.”
Conclusions
• Each of these institutions has stated,
explicitly or implicitly that,
– The Earth’s temperature is rising;
– Human generation of greenhouse gases,
deforestation, and land uses are a major
cause of temperature increase; and
– This increase is a serious threat to human
health.