I do respect science, but there really is a lot of hubris in it.
If you look back, there's a trail of errors: Alchemy, Miasma theory, Mesmer, Phrenology, Eugenics, etc. Now, really that's what makes science what it is. They get things wrong, they learn more, they make corrections, they move ahead. I wouldn't want it any other way!
However, if one were to hint that maybe the oh-so-wise scientist is wrong about something, they often get huffy and do the old: "Do you know who you're talking to??" bit.
There is, in fact, a lot left to learn. And some of what we know, well it just ain't so.
This happens. But scientists themselves, by and large, have an appropriate amount of humility.
The real problem is when lay people seize upon some "scientific" thing they heard and insist not only that it be taken as gospel truth, but that public policy be based upon it. Schiavo was just one example.
Global warming is another - because some scientists have made computer models of the oceano-atmospheric system, and those computer models predict a warming trend driven by CO2 emissions, a whole faction of lay people seem ready to revamp our entire economic system and fix it around the single goal of minimizing CO2 emissions. This isn't "science", it's scientism.
If you talk to the actual scientists working on these models, most of them would be very careful to hedge their predictions with a lot of caveats and assumptions. But those caveats are stripped away by the time they reach an Al Gore speech, and to me, that's the real problem.