Scientific opinion on climate change

Various national and international bodies and societies, and individual scientists have expressed opinions on climate change or global warming in the last few decades. This article addresses those opinions.

Table of contents

1 Pronouncements 2 Surveys 2.1 Bray and von Storch, 1996 2.2 Other Known Surveys 2.3 Statements on Global Warming 3 See Also

Pronouncements

Various prominent bodies have commented on global warming, most notably the Intergovernmental Panel on Climate Change (IPCC). National and international scientific groups have issued statements detailing and also summarizing the current state of scientific knowledge on the earth's climate see below. The original scientific literature is often inaccessible to the layperson (both literally, because they do not have access to appropriate libraries, and because the scientific writing style is unfamiliar), but the summaries and position statements are usually written to be intelligible to the informed layperson.

It is commonplace to see the assertion that the IPCC represents the consensus of opinion of climate scientists; it is also common to see this view disputed, e.g. SEPP. This page exists to provide evidence from published surveys (and possibly even petitions) of the general current of scientific thought rather than the opinions of individual scientists.

Surveys

Surveys have shown scientists split on the issue of whether global warming theory has been adequately proven, but with a majority agreeing that global warming will occur in future if human behavior does not change.

Bray and von Storch, 1996

In 1996 a survey of climate scientists on attitudes towards global warming and related matters was undertaken by Dennis Bray and Hans von Storch. The results were subsequently published in Bulletin of the American Meteorological Society Vol. 80, No. 3, March 1999 439-455. [1] The paper addressed the views of climate science, with a response rate of 40% from a mail survey questionnaire to 1000 scientists in Germany, the USA and Canada. Almost all scientists agreed that the skill of models was limited.

The abstract indicates an "incompatibility" between the "state of knowledge" and calls for "abatement measures":

The international consensus was, however, apparent regarding the utility of the knowledge to date: climate science has provided enough knowledge so that the initiation of abatement measures is warranted. However, consensus also existed regarding the current inability to explicitly specify detrimental effects that might result from climate change. This incompatibility between the state of knowledge and the calls for action suggests that, to some degree at least, scientific advice is a product of both scientific knowledge and normative judgment, suggesting a socioscientific construction of the climate change issue.

The survey was extensive, and asked numerous questions on many aspects of climate science, model formulation and utility, and science/public/policy interactions. To pick out some of the more vital topics, from the body of the paper:

The resulting questionnaire, consisting of 74 questions, was pre-tested in a German institution and after revisions, distributed to a total of 1,000 scientists in North America and Germany... The number of completed returns were as follows: USA 149, Canada 35, and Germany 228, a response rate of approximately 40%...

...With a value of 1 indicating the highest level of belief that predictions are possible and a value of 7 expressing the least faith in the predictive capabilities of the current state of climate science knowledge, the mean of the entire sample of 4.6 for the ability to make reasonable predictions of inter-annual variability tends to indicate that scientists feel that reasonable prediction is not yet a possibility... mean of 4.8 for reasonable predictions of 10 years ...mean of 5.2 for periods of 100 years...

...a response of a value of 1 indicates a strong level of agreement with the statement of certainty that global warming is already underway or will occur without modification to human behavior... ...the mean response for the entire sample was 3.3 indicating a slight tendency towards the position that global warming has indeed been detected and is underway. ...Regarding global warming as being a possible future event, there is a higher expression of confidence as indicated by the mean of 2.6.

Other Known Surveys

• Global Environmental Change Report, 1990: GECR climate survey shows strong agreement on action, less so on warming. Global Environmental Change Report 2, No. 9, pp. 1-3
• Stewart, T.R., Mumpower, J.L., and Reagan-Cirincione, P. (1992). Scientists' opinions about global climate change: Summary of the results of a survey. NAEP (National Association of Environmental Professionals) Newsletter, 17(2), 6-7. [1]

Statements on Global Warming

Some scientific organisations and individuals who have made position statements on climate change.

• Intergovernmental panel on climate change
• American Meteorological Society Statement
• American Geophysical Union position statement on greenhouse gases and climate change
• Climate Change Science: An Analysis of Some Key Questions, National Academy of Sciences, Commission on Geosciences, Environment and Resources, (Washington, DC: National Academy Press, 2001).
• Policy Statement on Climate Variability and Change by the American Association of State Climatologists (AASC)
• Evidence for global warming - and why we need to take action (prepared by Professor Peter Barrett FRSNZ (Director of the Antarctic Centre, Victoria University of Wellington))

The Summary Report of the World Climate Change Conference, Moscow, 2003, included: "The Intergovernmental Panel on Climate Change (IPCC) has provided the basis for much of our present understanding of knowledge in this field in its Third Assessment Report (TAR) in 2001. An overwhelming majority of the scientific community has accepted its general conclusions that climate change is occurring, is primarily a result of human emissions of greenhouse gases and aerosols, and that this represents a threat to people and ecosystems." [1]

See Also

global warming, climate change