The world consensus about anthropogenic climate change

The world consensus about anthropogenic climate change

Specifically, the consensus about anthropogenic climate change centers on the these points:
1. The climate is undergoing a pronounced warming trend beyond the range of natural variability
2. The major cause of most of the observed warming is rising levels of the greenhouse gas CO2
3. The rise in CO2 is the result of burning fossil fuels
4. If CO2 continues to rise over the next century, the warming will continue and the world's climate patterns will change drastically
5. A climate change of the projected magnitude over this time frame represents potential danger to human welfare and the environment

These conclusions have been explicitly endorsed by:
Academia Brasiliera de Ciências (Bazil)
Royal Society of Canada
Chinese Academy of Sciences
Academié des Sciences (France)
Deutsche Akademie der Naturforscher Leopoldina (Germany)
Indian National Science Academy
Accademia dei Lincei (Italy)
Science Council of Japan
Russian Academy of Sciences
Royal Society (United Kingdom)
National Academy of Sciences (United States of America)
Australian Academy of Sciences
Royal Flemish Academy of Belgium for Sciences and the Arts
Caribbean Academy of Sciences
Indonesian Academy of Sciences
Royal Irish Academy
Academy of Sciences Malaysia
Academy Council of the Royal Society of New Zealand
Royal Swedish Academy of Sciences

In addition to these national academies, the following institutions specializing in climate, atmosphere, ocean, and/or earth sciences have endorsed these conclusions:
NASA's Goddard Institute of Space Studies (GISS)
National Oceanic and Atmospheric Administration (NOAA)
National Academy of Sciences (NAS)
State of the Canadian Cryosphere (SOCC)
Environmental Protection Agency (EPA)
Royal Society of the United Kingdom (RS)
American Geophysical Union (AGU)
American Institute of Physics (AIP)
National Center for Atmospheric Research (NCAR)
American Meteorological Society (AMS)
Canadian Meteorological and Oceanographic Society (CMOS)

These organizations also agree with the consensus:
The Earth Institute at Columbia University
Northwestern University
University of Akureyri
University of Iceland
Iceland GeoSurvey
National Centre for Atmospheric Science UK
Climate Group
Climate Institute
Climate Trust
Wuppertal Institute for Climate Environment and Energy
Royal Meteorological Society
Community Research and Development Centre Nigeria
Geological Society of London
Geological Society of America
UK Centre for Social and Economic Research on the Global Environment
Pew Center on Global Climate Change
American Association for the Advancement of Science
National Research Council
Juelich Research Centre
US White House
US Council on Environmental Quality
US Office of Science Technology Policy
US National Climatic Data Center
US Department of Commerce
US National Environmental Satellite, Data, and Information Service
The National Academy of Engineering
The Institute of Medicine
UK Natural Environment Research Council
Office of Science and Technology Policy
Council on Environmental Quality
National Economic Council
Office of Management and Budget
The National Academy of Engineering
The Institute of Medicine
UK Natural Environment Research Council
Australian Government Bureau of Meteorology
Engineers Australia
American Chemical Society
American Association of Blacks in Energy
World Petroleum Council
The Weather Channel
National Geographic

The following companies agree with the consensus:
ABB
Air France
Alcan
Alcoa
Allian
American Electric Power
Aristeia Capital
BASF
Bayer
BP America Inc.
Calvert Group
Canadian Electricity Association
Caterpilliar Inc.
Centrica
Ceres
Chevron
China Renewable
Citigroup
ConocoPhillips
Covanta Holding Corporation
Deutsche Telekom
Doosan Babcock Energy Limited
Duke Energy
DuPont
EcoSecurities
Electricity de France North America
Electricity Generating Authority of Thailand
Endesa
Energettech Austraila Pty Ltd
Energy East Corporation
Energy Holding Romania
Energy Industry Association
Eni
Eskorn
ETG International
Exelon Corporation
ExxonMobil
F&C Asset Management
FPL Group
General Electric
German Electricity Association
Glitnir Bank
Global Energy Network Institute, Iberdrola
ING Group
Institute for Global Environmental Strategies
Interface Inc.
International Gas Union
International Paper
International Power
Marsh & McLennan Companies
Massachusetts Municipal Wholesale Electric Company
MEDIAS-France
MissionPoint Capital Partners
Munich Re
National Grid
National Power Company of Iceland
NGEN mgt II, LLC
NiSource
NRG Energy
PG&E Corporation
PNM Resources
Reykjavik Energy
Ricoh
Rio Tinto Energy Services
Rockefeller Brothers Fund
Rolls-Royce
Societe Generale de Surveillance (SGS Group)
Stora Enso North America
Stratus Consulting
Sun Management Institute
Swiss Re
UCG Partnership
US Geothermal
Verde Venture Partners
Volvo

In addition, the scientific consensus is also endorsed by the CEO's of the following companies:
A. O. Smith Corporation
Abbott Laboratories
Accenture Ltd.
ACE Limited
ADP
Aetna Inc.
Air Products and Chemicals, Inc.
AK Steel Corporation
Alcatel-Lucent
Allstate Insurance Company
ALLTEL Corporation
Altec Industries, Inc.
American Electric Power Company, Inc.
American Express Company
American International Group, Inc.
Ameriprise Financial
AMR Corporation/American Airlines
Anadarko Petroleum Corporation
Apache Corporation
Applera Corporation
Arch Coal, Inc.
Archer Daniels Midland Company
ArvinMeritor, Inc.
AstraZeneca Pharmaceuticals LP
Avery Dennison Corporation
Avis Budget Group, Inc.
Bechtel Group, Inc.
BNSF Railway
Boeing Company
Brink's Company
CA
Carlson Companies, Inc.
Case New Holland Inc.
Ceridian Corporation
Chemtura Corporation
Chubb Corporation
CIGNA Corporation
Coca-Cola Company
Constellation Energy Group, Inc.
Convergys Corporation
Con-way Incorporated
Corning Incorporated
Crane Co.
CSX Corporation
Cummins Inc.
Deere & Company
Deloitte Touche Tohmatsu
Delphi Corporation
Dow Chemical Company
Eastman Chemical Company
Eastman Kodak Company
Eaton Corporation
EDS
Eli Lilly and Company
EMC Corporation
Ernst & Young, L.L.P.
Fannie Mae
FedEx Corporation
Fluor Corporation
FMC Corporation
Freddie Mac
General Mills, Inc.
General Motors Corporation
Goldman Sachs Group, Inc.
Goodrich Corporation
Harman International Industries, Inc.
Hartford Financial Services Group
Home Depot, Inc., The
Honeywell International, Inc.
HSBC - North America
Humana Inc.
IBM Corporation
Ingersoll-Rand Company
International Textile Group
ITT Corporation
Johnson Controls, Inc.
JP Morgan Chase & Co.
KPMG LLP
Liberty Mutual Group
MassMutual
MasterCard Incorporated
McGraw-Hill Companies
McKesson Corporation
MeadWestvaco Corporation
Medco Health Solutions, Inc.
Merck & Co., Inc.
Merrill Lynch & Company, Inc.
MetLife, Inc.
Morgan Stanley
Motorola, Inc.
Nasdaq Stock Market, Inc.
National Gypsum Company
Nationwide
Navistar International Corporation
New York Life Insurance Company
Norfolk Southern Corporation
Northwestern Mutual Life Insurance Company
Nucor Corporation
NYSE Group, Inc.
Office Depot, Inc.
Owens Corning (Reorganized) Inc.
Pactiv Corporation
Peabody Energy Corporation
Pfizer Inc
PPG Industries, Inc.
Praxair, Inc.
PricewaterhouseCoopers LLP
Principal Financial Group
Procter & Gamble Company
Prudential Financial
Realogy Corporation
Rockwell Automation, Inc.
Ryder System, Inc.
SAP America, Inc.
Sara Lee Corporation
SAS Institute Inc.
Schering-Plough Corporation
Schneider National, Inc.
ServiceMaster Company
Siemens Corporation
Southern Company
Springs Global US, Inc.
Sprint Nextel
St. Paul Travelers Companies, Inc.
State Farm Insurance Companies
Tenneco
Texas Instruments Incorporated
Textron Incorporated
Thermo Fisher Scientific Inc.
TIAA-CREF
Tyco Electronics
Tyco International Ltd.
Union Pacific Corporation
Unisys Corporation
United Technologies Corporation
UnitedHealth Group Incorporated
USG Corporation
Verizon Communications
W.W. Grainger, Inc.
Western & Southern Financial Group
Weyerhaeuser Company
Whirlpool Corporation
Williams Companies, Inc.
Xerox Corporation
YRC Worldwide Inc

 

Oh yeah?

 

Yeah!!!


The Consensus on Global Warming:
From Science to Industry & Religion


***

 

And, are you aware that the sun is getting warmer each year as well? That's right, The sun will warm to the point that no water will exist in liquid form, anywhere on earth. NOW, STOP GLOBAL WARMING.

 

Pfft.. the Sun lol. In 4.5 billion years the electron degeneracy pressure will be too much and the sun will have gone supernova, generating a shockwave blasting all the planets in our solar system. SO MUCH FOR YOUR SUN.

 

Are you aware that that is total bullshit?

 

The last time I researched this, five years ago or so, climatologists were NOT in concensus that humans are the main cause. There was strong concensus among scientists in other disciplines, however.



Sent from my SCH-I510 using Tapatalk

 

Do you have a point with this?

 

Hmm, pretty overwhelming consensus I'd say...


I scrolled through the list kinda fast.... Wow, religion too huh? Cool:coffee:

ZW

 

Perhaps if you'd tried "researching" it from reputable sources rather than just listening to Rush or Glenn or some denier cult nitwit on the internet, you would actually have the facts but as it is, you're just plain wrong.

Expert credibility in climate change

Proceedings of the National Academies of the United States of America

1. William R. L. Anderegg a , 1 ,
2. James W. Prall b ,
3. Jacob Harold c , and
4. Stephen H. Schneider a , d , 1

+ Author Affiliations

1. aDepartment of Biology, Stanford University, Stanford, CA 94305;
2. bElectrical and Computer Engineering, University of Toronto, Toronto, ON, Canada M5S 3G4;
3. c William and Flora Hewlett Foundation, Palo Alto, CA 94025; and
4. dWoods Institute for the Environment, Stanford University, Stanford, CA 94305

Published online before print June 21, 2010
doi: 10.1073/pnas.1003187107
PNAS June 21, 2010
Free via Open Access: OA
Full Text (PDF)

Abstract

Although preliminary estimates from published literature and expert surveys suggest striking agreement among climate scientists on the tenets of anthropogenic climate change (ACC), the American public expresses substantial doubt about both the anthropogenic cause and the level of scientific agreement underpinning ACC. A broad analysis of the climate scientist community itself, the distribution of credibility of dissenting researchers relative to agreeing researchers, and the level of agreement among top climate experts has not been conducted and would inform future ACC discussions. Here, we use an extensive dataset of 1,372 climate researchers and their publication and citation data to show that (i) 97–98% of the climate researchers most actively publishing in the field support the tenets of ACC outlined by the Intergovernmental Panel on Climate Change, and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers.

And here's another one -

Survey: Scientists Agree Human-Induced Global Warming is Real

UIC News Release (free to reproduce)
University of Illinois at Chicago Office of Public Affairs (MC 288)

While the harsh winter pounding many areas of North America and Europe seemingly contradicts that global warming continues unabated, a new survey finds consensus among scientists about the reality of climate change and its likely cause.

A group of 3,146 earth scientists surveyed around the world overwhelmingly agree that in the past 200-plus years, mean global temperatures have been rising, and that human activity is a significant contributing factor in changing mean global temperatures.

Peter Doran, University of Illinois at Chicago associate professor of earth and environmental sciences, along with former graduate student Maggie Kendall Zimmerman, conducted the survey late last year.

The findings appear today in Eos, the newspaper of earth and space sciences published by American Geophysical Union.

In trying to overcome criticism of earlier attempts to gauge the view of earth scientists on global warming and the human impact factor, Doran and Kendall Zimmerman sought the opinion of the most complete list of earth scientists they could find, contacting more than 10,200 experts around the world listed in the 2007 edition of the American Geological Institute's Directory of Geoscience Departments.

Experts in academia and government research centers were e-mailed invitations to participate in the on-line poll conducted by the website questionpro.com. Only those invited could participate and computer IP addresses of participants were recorded and used to prevent repeat voting. Questions used were reviewed by a polling expert who checked for bias in phrasing, such as suggesting an answer by the way a question was worded. The nine-question survey was short, taking just a few minutes to complete.

Two questions were key: have mean global temperatures risen compared to pre-1800s levels, and has human activity been a significant factor in changing mean global temperatures.

About 90 percent of the scientists agreed with the first question and 82 percent the second.

In analyzing responses by sub-groups, Doran found that climatologists who are active in research showed the strongest consensus on the causes of global warming, with 97 percent agreeing humans play a role. Petroleum geologists and meteorologists were among the biggest doubters, with only 47 and 64 percent respectively believing in human involvement. Doran compared their responses to a recent poll showing only 58 percent of the public thinks human activity contributes to global warming.

"The petroleum geologist response is not too surprising, but the meteorologists' is very interesting," he said. "Most members of the public think meteorologists know climate, but most of them actually study very short-term phenomena."

He was not surprised, however, by the near-unanimous agreement by climatologists.

"They're the ones who study and publish on climate science. So I guess the take-home message is, the more you know about the field of climate science, the more you're likely to believe in global warming and humankind's contribution to it."

Doran and Kendall Zimmerman conclude that "the debate on the authenticity of global warming and the role played by human activity is largely nonexistent among those who understand the nuances and scientific basis of long-term climate processes." The challenge now, they write, is how to effectively communicate this to policy makers and to a public that continues to mistakenly perceive debate among scientists.

Copyright ©2011, The Board of Trustees of the University of Illinois.

(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)

 

Do you have a point with this?

Just that scientists most specialized in the study of longterm climate change are the least likely to be confident that humans are the major factor. Climatologists seem to have to deal with a far larger puzzle, taking into account the orbital considerations, geologic factors- anything that affects distribution of heat. Anyhow, it's been a few years but last I checked climatologists specifically had a lot of doubters in their ranks.

I wouldn't be surprised if some of the predictions/projections are softened in the coming decades. We have seen it in other disciplines... Not long ago there seemed to be a widespread belief that dinosaurs were taken out by an asteroid impact. More recent findings now suggest that the 'saurs were all but gone well before that. I'm not criticizing science here, just underscoring that it works, though often the puzzle gets bigger as we add and fit pieces.

Hope I was clear; today started yesterday afternoon so it's been a long one! And now I seek sleep, probably dreaming of dinosaurs chasing scientists...

 

Completely, oppositely wrong. See post #10. Studies of climate scientists show just the opposite:
"In analyzing responses by sub-groups, Doran found that climatologists who are active in research showed the strongest consensus on the causes of global warming, with 97 percent agreeing humans play a role.
He was not surprised, however, by the near-unanimous agreement by climatologists.
"They're the ones who study and publish on climate science. So I guess the take-home message is, the more you know about the field of climate science, the more you're likely to believe in global warming and humankind's contribution to it." "

 

Here's a good summary of the actual world scientific conclusions and consensus about anthropogenic global warming. These are just some excerpts from the original article; just a sampling of the actual international scientific support for the conclusions of the climate scientists on AGW/CC. Follow the link and go look at the main article

Scientific opinion on climate change

From Wikipedia, the free encyclopedia

The predominant scientific opinion on climate change is that the Earth is in an ongoing phase of global warming very likely primarily caused by an enhanced greenhouse effect due to the anthropogenic release of carbon dioxide and other greenhouse gases. This scientific consensus is expressed in synthesis reports, scientific bodies of national or international standing, and surveys of opinion among climate scientists. Individual scientists, universities, and laboratories contribute to the overall scientific opinion via their peer-reviewed publications, and the areas of collective agreement and relative certainty are summarised in these high level reports and surveys. Self-selected lists of individuals' opinions, such as petitions, are not normally considered to be part of the scientific process.

National and international science academies and scientific societies have assessed the current scientific opinion, in particular on recent global warming. These assessments have largely followed or endorsed the Intergovernmental Panel on Climate Change (IPCC) position of January 2001 which states:

"An increasing body of observations gives a collective picture of a warming world and other changes in the climate system... There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."[1]
​

No scientific body of national or international standing has maintained a dissenting opinion.


The U.S. Global Change Research Program reported in June, 2009 that:

Observations show that warming of the climate is unequivocal. The global warming observed over the past 50 years is due primarily to human-induced emissions of heat-trapping gases. These emissions come mainly from the burning of fossil fuels (coal, oil, and gas), with important contributions from the clearing of forests, agricultural practices, and other activities.

Climate-related changes have already been observed globally and in the United States. These include increases in air and water temperatures, reduced frost days, increased frequency and intensity of heavy downpours, a rise in sea level, and reduced snow cover, glaciers, permafrost, and sea ice. A longer ice-free period on lakes and rivers, lengthening of the growing season, and increased water vapor in the atmosphere have also been observed. Over the past 30 years, temperatures have risen faster in winter than in any other season, with average winter temperatures in the Midwest and northern Great Plains increasing more than 7°F. Some of the changes have been faster than previous assessments had suggested. ​

As the representative of the world’s scientific and engineering academies, the InterAcademy Council (IAC) issued a report in 2007 titled Lighting the Way: Toward a Sustainable Energy Future.

Current patterns of energy resources and energy usage are proving detrimental to the long-term welfare of humanity. The integrity of essential natural systems is already at risk from climate change caused by the atmospheric emissions of greenhouse gases.[20]

Concerted efforts should be mounted for improving energy efficiency and reducing the carbon intensity of the world economy. ​

In 2007, the European Academy of Sciences and Arts issued a formal declaration on climate change titled Let's Be Honest:

Human activity is most likely responsible for climate warming. Most of the climatic warming over the last 50 years is likely to have been caused by increased concentrations of greenhouse gases in the atmosphere. Documented long-term climate changes include changes in Arctic temperatures and ice, widespread changes in precipitation amounts, ocean salinity, wind patterns and extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones. The above development potentially has dramatic consequences for mankind’s future.​

As the world's largest general scientific society, the American Association for the Advancement of Science adopted an official statement on climate change in 2006:

The scientific evidence is clear: global climate change caused by human activities is occurring now, and it is a growing threat to society....The pace of change and the evidence of harm have increased markedly over the last five years. The time to control greenhouse gas emissions is now.​

The American Chemical Society stated:

Careful and comprehensive scientific assessments have clearly demonstrated that the Earth’s climate system is changing rapidly in response to growing atmospheric burdens of greenhouse gases and absorbing aerosol particles (IPCC, 2007). There is very little room for doubt that observed climate trends are due to human activities. The threats are serious and action is urgently needed to mitigate the risks of climate change.

The reality of global warming, its current serious and potentially disastrous impacts on Earth system properties, and the key role emissions from human activities play in driving these phenomena have been recognized by earlier versions of this ACS policy statement (ACS, 2004), by other major scientific societies, including the American Geophysical Union (AGU, 2003), the American Meteorological Society (AMS, 2007) and the American Association for the Advancement of Science (AAAS, 2007), and by the U. S. National Academies and ten other leading national academies of science (NA, 2005). ​

In November 2007, the American Physical Society (APS) adopted an official statement on climate change:

Emissions of greenhouse gases from human activities are changing the atmosphere in ways that affect the Earth's climate. Greenhouse gases include carbon dioxide as well as methane, nitrous oxide and other gases. They are emitted from fossil fuel combustion and a range of industrial and agricultural processes.

The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now.

Because the complexity of the climate makes accurate prediction difficult, the APS urges an enhanced effort to understand the effects of human activity on the Earth’s climate, and to provide the technological options for meeting the climate challenge in the near and longer terms. The APS also urges governments, universities, national laboratories and its membership to support policies and actions that will reduce the emission of greenhouse gases. ​

The American Geophysical Union (AGU) statement, adopted by the society in 2003 and revised in 2007, affirms that rising levels of greenhouse gases have caused and will continue to cause the global surface temperature to be warmer:

The Earth's climate is now clearly out of balance and is warming. Many components of the climate system—including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons—are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century. Global average surface temperatures increased on average by about 0.6°C over the period 1956–2006. As of 2006, eleven of the previous twelve years were warmer than any others since 1850. The observed rapid retreat of Arctic sea ice is expected to continue and lead to the disappearance of summertime ice within this century. Evidence from most oceans and all continents except Antarctica shows warming attributable to human activities. Recent changes in many physical and biological systems are linked with this regional climate change. A sustained research effort, involving many AGU members and summarized in the 2007 assessments of the Intergovernmental Panel on Climate Change, continues to improve our scientific understanding of the climate.​

In 2006, the Geological Society of America adopted a position statement on global climate change. It amended this position on April 20, 2010 with more explicit comments on need for CO2 reduction.

Decades of scientific research have shown that climate can change from both natural and anthropogenic causes. The Geological Society of America (GSA) concurs with assessments by the National Academies of Science (2005), the National Research Council (2006), and the Intergovernmental Panel on Climate Change (IPCC, 2007) that global climate has warmed and that human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s. If current trends continue, the projected increase in global temperature by the end of the twentyfirst century will result in large impacts on humans and other species. Addressing the challenges posed by climate change will require a combination of adaptation to the changes that are likely to occur and global reductions of CO2 emissions from anthropogenic sources.​

The American Meteorological Society (AMS) statement adopted by their council in 2003 said:

There is now clear evidence that the mean annual temperature at the Earth's surface, averaged over the entire globe, has been increasing in the past 200 years. There is also clear evidence that the abundance of greenhouse gases in the atmosphere has increased over the same period. In the past decade, significant progress has been made toward a better understanding of the climate system and toward improved projections of long-term climate change... Human activities have become a major source of environmental change. Of great urgency are the climate consequences of the increasing atmospheric abundance of greenhouse gases... Because greenhouse gases continue to increase, we are, in effect, conducting a global climate experiment, neither planned nor controlled, the results of which may present unprecedented challenges to our wisdom and foresight as well as have significant impacts on our natural and societal systems.​

 

while global warming deniers may mostly be on the fossil fuel payroll, I think that there are a small number of scientists who legitimately question some aspect of the general consensus.

I think there is a professor at MIT who thinks that feedback mechanisms would balance the warming created by increased co2 levels.

On the other hand, this guy smokes a pack of cigarettes a day, and apparently doesn't believe that smoking causes cancer.

I think that one can legitimately criticize just about any scientific idea. It's not possible to get a 100% consensus on anything.

It's a bit like having a pill that 97% of doctors say will kill you, and 3% say won't.

If the consensus is correct, the earth will be severely fucked if we don't control co2

seems to me that the potential consequences of global climate change justify efforts to control co2

 

I heard about this late last night on CBC radio;

mm on Nov 21, 2011 at 9:40 pm
The World Meteorological Organization reported today that:

The amount of greenhouse gases in the atmosphere reached a new high in 2010 since pre-industrial time and the rate of increase has accelerated, according to the World Meteorological Organization’s Greenhouse Gas Bulletin….Between 1990 and 2010, according to the report, there was a 29% increase in radiative forcing — the warming effect on our climate system — from greenhouse gases. Carbon dioxide accounted for 80% of this increase.

http://thinkprogress.org/romm/2011/...-high-growth-methane-levels-are-rising-again/

ZW
​

 

We're in general agreement but just to be clear about something, "consensus" does not mean a "100%" agreement. Here's some very relevant information about 'consensus'.

Scientific consensus
From Wikipedia, the free encyclopedia

Scientific consensus is the collective judgment, position, and opinion of the community of scientists in a particular field of study. Consensus implies general agreement, though not necessarily unanimity. Scientific consensus is not by itself a scientific argument, and it is not part of the scientific method. Nevertheless, consensus may be based on both scientific arguments and the scientific method.[1]

Consensus is normally achieved through communication at conferences, the publication process, replication (reproducible results by others) and peer review. These lead to a situation in which those within the discipline can often recognize such a consensus where it exists, but communicating to outsiders that consensus has been reached can be difficult, because the 'normal' debates through which science progresses may seem to outsiders as contestation.[2] On occasion, scientific institutes issue position statements intended to communicate a summary of the science from the "inside" to the "outside" of the scientific community [see post #14]. In cases where there is little controversy regarding the subject under study, establishing what the consensus is can be quite straightforward.

Uncertainty and scientific consensus in policy making

In public policy debates, the assertion that there exists a consensus of scientists in a particular field is often used as an argument for the validity of a theory and as support for a course of action by those who stand to gain from a policy based on that consensus. Similarly arguments for a lack of scientific consensus are often encouraged by sides who stand to gain from a more ambiguous policy.

People of various backgrounds (political, scientific, media, action groups, and so on) have argued that there is a scientific consensus on the causes of global warming. The historian of science Naomi Oreskes published an article in Science reporting that a survey of the abstracts of 928 science articles published between 1993 and 2003 showed none which disagreed explicitly with the notion of anthropogenic global warming.[10] In an editorial published in the Washington Post, Oreskes stated that those who opposed these scientific findings are amplifying the normal range of scientific uncertainty about any facts into an appearance that there is a great scientific disagreement, or a lack of scientific consensus.[11][2] Oreskes's findings were replicated by other methods that require no interpretation.

The theory of evolution through natural selection is an accepted part of the science of biology, to the extent that few observations in biology can be understood without reference to natural selection and common descent. Opponents of evolution claim that there is significant dissent on evolution within the scientific community.[12] The wedge strategy, an ambitious plan to supplant scientific materialism seen as inimical to religion, with a religion-friendly theistic science, depended greatly on seeding and building on public perceptions of absence of consensus on evolution.[13] Stephen Jay Gould has argued that creationists misunderstand the nature of the debate within the scientific community, which is not about "if" evolution occurred, but "how" it occurred.[12]

The inherent uncertainty in science, where theories are never proven but can only be disproven (see falsifiability), poses a problem for politicians, policymakers, lawyers, and business professionals. Where scientific or philosophical questions can often languish in uncertainty for decades within their disciplinary settings, policymakers are faced with the problems of making sound decisions based on the currently available data, even if it is likely not a final form of the "truth". The tricky part is discerning what is close enough to "final truth". For example, social action against smoking probably came too long after science was 'pretty consensual'.[2]

Certain domains, such as the approval of certain technologies for public consumption, can have vast and far-reaching political, economic, and human effects should things run awry of the predictions of scientists. However, insofar as there is an expectation that policy in a given field reflect knowable and pertinent data and well-accepted models of the relationships between observable phenomena, there is little good alternative for policy makers than to rely on so much of what may fairly be called 'the scientific consensus' in guiding policy design and implementation, at least in circumstances where the need for policy intervention is compelling. While science cannot supply 'absolute truth' (or even its complement 'absolute error') its utility is bound up with the capacity to guide policy in the direction of increased public good and away from public harm. Seen in this way, the demand that policy rely only on what is proven to be "scientific truth" would be a prescription for policy paralysis and amount in practice to advocacy of acceptance of all of the quantified and unquantified costs and risks associated with policy inaction.[2] Such considerations informed the development of 'the precautionary principle'.

No part of policy formation on the basis of the ostensible scientific consensus precludes persistent review either of the relevant scientific consensus or the tangible results of policy. Indeed, the same reasons that drove reliance upon the consensus drives the continued evaluation of this reliance over time—and adjusting policy as needed.


********************************