At what point dose a scientist loose credibility? if a scientist argued against the link between smoking and cancer in the 80s opposing the consensus of the time.
then in the 90s argued against the link between CFCs and the ozone hole again opposing the consensus of the time. now they are saying global warming is not man made. do they loose creditability at all?

i am referring to:
Patrick Michaels
Fred Singer
Frederick Seitz

Looks to me like Singer%26#039;s scientific work peaked in the 50%26#039;s. He was involved with the oil industry in the 70s and 80s. His work since the early 1990s seems to be focused on his SEPP advocacy organization, which has accepted funds from ExxonMobil.
http://www.exxonsecrets.org/html/orgfact...
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Wikipedia: Global warming controversy
http://en.wikipedia.org/wiki/Global_warm...

Several skeptical scientists—Fred Singer, Fred Seitz and Patrick Michaels—have been linked to organizations funded by ExxonMobil and Philip Morris for the purpose of promoting global warming skepticism (see section: Risks of passive smoking). Similarly, groups employing global warming skeptics, such as the George C. Marshall Institute, have been criticized for their ties to fossil fuel companies.

On February 2, 2007, The Guardian stated that Kenneth Green, a Visiting Scholar with AEI, had sent letters to scientists in the UK and the U.S., offering US$10,000 plus travel expenses and other incidental payments in return for essays with the purpose of %26quot;highlight[ing] the strengths and weaknesses of the IPCC process,%26quot; specifically regarding the IPCC Fourth Assessment Report.

A furor was raised when it was revealed that the Intermountain Rural Electric Association (an energy cooperative that draws a significant portion of its electricity from coal-burning plants) donated $100,000 to Patrick and his group, New Hope Environmental Services, and solicited additional private donations from its members.

I recall reading that at least one of them (Singer I think) also claimed there was no relationship between sulfur emissions and acid rain.

Basically they seem not to care what the scientific evidence shows and support whatever benefits the right-wing political groups. It amazes me that any scientist can do this, but I guess there%26#039;s always a few bad apples in every bunch.

It also amazes me that deniers like shapeshifter will place the conclusions of right-wing political groups like SPPI (Science and Public Policy Institute) over that of groups of scientists like the AGU. And that they purposefully misrepresent the AGU%26#039;s conclusions, which is that the Earth%26#039;s climate is out of balance *and* warming, not just out of balance *because* it%26#039;s warming. http://en.wikipedia.org/wiki/SPPI

I would say a scientist loses credibility the moment he or she interprets data with a noticeable bias. Or when they change their conclusion because it isn%26#039;t what their employer/government wants to hear. That just isn%26#039;t science anymore.

Yes they do. A %26quot;scientific consensus%26quot; isn%26#039;t jsut a bunch of scientists getting together and voting or something. It is a term scientists use to indicate that the body of evidence supporting a particular hypothesis has become so strong that there is no longer any possible (rational) doubt that that particular hypothesis is true. In short--the hypothesis has been proven.

Scientists, however, are just people. Some develop mental problems--or get bought off by special interests, or whatever. So you always see a few, on a variety of issues, who go off into la-la land. And yes, that does cost them their credibility.

BTW--there IS a form of opposing the existing paradign tha tis NOT inappropriate. That is when some particualr scientist picks up on soething--a new approach or idea--that goes beyond the existing body of knowledge to the extent it simply doesn%26#039;t fit the existingmodels at all. But when that happens, such scientists do not go around claiming %26quot;there%26#039;s a liberal conspiracy,%26quot; yada, yada, yada. Instead they get to work doing the hard wrk of devising and testing their ideas. And--more often than not, find out they were wrong. But when they do turn out to be right--they do it by providing solid evidence, not by making unsupported claims or demanding that junk science be accepted as evidence.

Hypotheticallly, a scientists could do hust this with global warming--in SOME respects. No legitimate scientist is going to claim %26quot;global warming does not exist%26quot; or that it isn%26#039;t man-made. thoose are proven facts. But we do,in fact, have a challenge to the accepted paradigm right now--the idea of %26quot;global dimming.%26quot; here, a few scientists have suggested taht some pollutants (mainly particulate exaust from jet aircraft) may be blockingthe suns light to a degree, producing a small but measurable tendency for reduced temperatures.

But look at the difference with these scientists. First, they are not claiming they have proven teir case--they don%26#039;t have enough evidence to do that (yet, anyway). And they have pointed out that, if they are right, this does not %26quot;disprove%26quot; global warming--in fact the opposite: global dimming, if it proves to be valid, would have a %26quot;masking%26quot; effect and be slowing global warming--meaning that the global warming is actually stonger than previously thought.

But these scientists who are (legitimately) questining accepted models--are not trying to deny proven facts--they are trying to make our knowledge mor e comprehensive and complete.

When their paycheck is signed, %26quot;EXXON%26quot;

Scientists loose credibility when they reject the traditional peer review process and incorporate their own rules such as rejecting reviewers comments because only one paper supports their idea while accepting other comments supported by one paper AS LONG AS it supports the idea of AGW. The reviewers didnt review every chapter. They tried to make up a policy for the entire world to follow even though they didnt have reviewers from a lot of places in the world. (This refers to the IPCC, forgot to mention)

I would say that is where they loose credibility.

Also, in the case of the American Geophysical Union, they ruined it in their first sentence of their paper by stating something implying they already had an agenda. They said %26quot;the earth%26#039;s climate is now clearly out of balance and is warming.%26quot;

SPPI: %26quot;But if mere warming or cooling is a sign of being out of balance, one could truthfully say that earth%26#039;s climate is almost always %26quot;out of balance,%26quot; which suggests that its current condition is actually normal. %26quot;

These seem to be the same types who deny most of the pollution and environmental devestation that man has visited upon the earth.

Like I said in a previous post, when I looked at car exhaust as maybe a 10 yr old boy, about 50 years ago, I wondered how much the atmosphere could take before it is poisoned.
The answer, that there are real limits, is so obvious, it boggles my mind how some can%26#039;t see it. Same applies to water pollution both fresh and salt and many other things that are equally obvious. I guess some can%26#039;t resist seeing such claims as some kind of communist conspiracy or whatever. Oh well, I guess it takes all types.