Don't climate "scientists" have a personal bias invested in a certain outcome?
No. That's the argument made over and over again, but it isn't actually the way science works. In the long run, scientists gain kudos by getting the right answer. Despite the arguments of deniers, scientists aren't idiots.
And in the scientific community, the standard is: the more sensational the claim, the more evidence is required. And climate "science" has made some pretty sensational claims
Again, wrong. In some ways, the problem with actual climate science (not what's in the press, real science) is that the effect isn't sensational. The climate scientists are claiming that anthropogenic carbon dioxide has warmed the planet by on the order of one degree-- far too little for anybody to actually personally notice, although well measurable on a statistical basis. That's only a few percent of the natural greenhouse warming (which is well understood, and not at all controversial, even though it's exactly the same physics).
The reason that denial is so easy is that the effect is so small. Over the long term, of course, it does built up-- but that's brings in the argument "why should we do anything for posterity? What has posterity ever done for us?"
that have a history if not coming true.
Again, wrong. I've been tracking the predictions to data for several years now, and climate modelling still seems to be pretty good; tracking to well within statistical error. The only people who say it isn't are saying so by cherry-picking data that isn't statistically significant.
But we knew that: if the greenhouse effect didn't exist, the Earth would be a frozen snowball.