Ever again, see Feynman's "Cargo Cult Science." We _all_ are given to fooling ourselves. That is why the best of us hold ourselves to the highest standards, rather than the lowest common denominator of "what everyone else does." With climate warming, the problem is one of paradigm.

On the other hand, the NIH and other federal agencies do have auditors, do report fraud, and do punish the errant. "... on June 28, 2006, Eric Poehlman was sentenced to a year and a day in prison for defrauding the National Institutes of Health. The False Claims Act of 1963 (Amended 1986) makes it a crime to lie to the government in a contract. The same law provides monetary rewards to whistleblowers." from my class paper cited in this thread.

On the other other hand, if you cheat General Electric or General Motors or General Mills, not much can be done, except to fire you. Bell Labs Lucent could do nothing to Jan Hendrik Schoen. However, his university rescinded his doctorate, even though their audit did confirm the veracity of his work. The university exists as a law unto itself. That was the intention from the very first and what "university" means - not that it studies all knowledge, but that it is whole within itself, legally.

My highest recommendation is for James Hogan's, "Kicking the Sacred Cow."
From the publisher:
As bestselling author James P. Hogan demonstrates in this fact-filled and thoroughly documented study, science has its own roster of hidebound pronouncements which are Not to be Questioned. Among the dogma-laden subjects he examines are Darwinism, global warming, the big bang, problems with relativity, radon and radiation, holes in the ozone layer, the cause of AIDS, and the controversy over Velikovsky. Hogan explains the basics of each controversy with his clear, informative style, in a book that will be fascinating for anyone with an interest in the frontiers of modern science.
Samples from the book:
http://www.baen.com/chapters/W200407/074...

"Several differently framed searches in two large academic databases supported the easy claim that misconduct, fraud and hoax were unknown in science before 1950 and remain rare today. The JSTOR database contains three million full length articles from 1200 journals, almost all peer reviewed academic periodicals, with significant titles going back before 1900. Searches uncovered zero articles about misconduct in scientific research from 1900 to 1950. [The Piltdown Hoax was an exception, but was so egregious as to be considered an outlier.] From 1950 to the present, 40 articles addressed the related problems. An obvious upswing occurred after 1987. The Gale CENGAGE Learning PowerSearchTM database covering 1980-2010 yielded 56 titles. Of course, many were reports of headline news about Jan Hendrik Schön and other immediacies in (nominally) peer-reviewed news magazines such as Science, Nature and Science News.

"On the other hand, a relatively recent academic research survey reported that misconduct is shockingly common. Fifteen years ago, “A Social Control Perspective on Scientific Misconduct” by Edward J. Hackett appeared in The Journal of Higher Education (Vol. 65, No. 3, pp. 242-260). A survey covering the five years 1983-1988 of members of the Council of Graduate Schools found that 40% (118) received allegations of possible misconduct. Those institutions whose external funding exceeded $50 million “were far more likely than others (69% to 19%) to hear such allegations.” The same article cited a 1991 survey of AAAS members in which 27% of 469 respondents claimed to have “personally encountered or witnessed scientific research that they suspected was fabricated, falsified or plagiarized during the past ten years.” In that same issue of the JHE, Mary Frank Fox wrote: “During the last fifteen years, hardly a year has gone by without the surfacing of a notorious case of misconduct in science.” She then cited nine by name." -- ("PROCEDURAL MISCONDUCT BY SCIENTISTS: PREVENTION AND REMEDIES" By Michael E. Marotta; PHYS 406: Ethical Issues in Physics; Dr. Patrick L. Koehn; Eastern Michigan University; Winter 2010.)

20 percent - seems as good as any other guess.
The surprise is that so many regard scientists as superior to the general population in ethics -should there be such a thing.
Rather the rule is that nearly everyone, certainly professionals, support their employer, institution, industry, or association by at one level ignoring unpleasant news, then by slanting evidence, and some of them actually make up data. The field of climate science is full of that. Having a single source of money, such as government, is a good indicator that there will be more fudging than is usual.

You are right. Academic misconduct is not rare.

_Embargoed Science_ by Vincent Kierman (University of Illinois Press, 2006). Major academic journals such as Nature, Science, the New England Journal of Medicine, and a hundred or so others, have a policy of announcing important publications by sending press releases to major mainstream media on the condition that the reporters not publish until the journal does. The result is loud bursts of astounding science stories breaking on our awareness ... which then fade … until the next time. The true costs include the loss of reflection and review, as contradictory findings roll out over the years without in-depth comparison and contrast. Another cost is the loss of independence both of the news media which will not pursue a story beyond the press release; and also among the scientists who are constrained to divulge only what they publish in peer-reviewed journals.
"Four Books About Bad Science": http://necessaryfacts.blogspot.com/2013/...

_When Science Goes Wrong: Twelve Tales from the Dark Side of Discovery_ by Simon LeVay (Plume Penguin, 2008). LeVay lays out his facts in careful narratives. In many cases, he interviewed the key actors, albeit some years after the events. He marshals the pros and cons before stating his final conclusion. The cases come from a several sciences, including volcanology, criminology, meteorology, microbiology, genetics, and nuclear physics.

In 1993, geologists attended a conference in Columbia where the Galeras volcano had become active. They visited the calderon, climbing down into the crater. When it erupted, most of them were killed. Among the survivors was the only scientist actually wearing the protective gear mandated by the National Science Foundation. Some of the victims were in jeans and sneakers.

The case from criminal forensics about Josiah Sutton of Houston, Texas, took DNA evidence past the confines of even the Innocence Project. In this case, the so-called gold standard of physical criminalistics proved to be fool’s gold. The police lab had committed a series of mistakes, some perhaps accidental and careless, others apparently purposefully fraudulent. The victim wrongly identified two men as her attackers. When the DNA samples matched neither man, the prosecutor insisted on their guilt, and posited the existence of a third unidentified attacker. This is a common ploy with prosecutors who refuse to admit their mistake.
"Four Books About Bad Science":http://necessaryfacts.blogspot.com/2013/01/four-books-about-bad-science.html