How Science Works
Most people should have learned the scientific method. Form a hypothesis, test the hypothesis, revise based upon the data. It is very objective: a great scientist goes where the data leads.
The reality of science is very different than you learned in school. When a scientist forms a hypothesis, they become very emotionally invested in it. If they data doesn't confirm their hypothesis, their brains go into overdrive to figure out why. They will figure out any reason imaginable to throw out disagreeable data. Of course, if they data confirms their hypothesis, no such scrutiny is done.
This is why the peer review process is so important: those who disagree with the hypothesis will apply great scrunity to both the data and the methods for obtaining it. They may devise counter-experiments to disprove the hypothesis. This continues for years. Rival scientists are often very contentious, subjecting their intellectual opponents to ridicule and worse. It can take many years, often decades, but eventually enough data and facts are gathered that a theory emerges victories as one side admits defeat and there are virtually no credible scientists left opposed.
The human nature component affects all scientists, great and small. Einstein famously refused to believe in quantuum mechanics until the day he died, though it was well established by then.
Lastly, let's not forget how politics fits into all this. The greatest funding of science comes from government. Global warming advocates frequently paint opponents as being in the pocked of "big oil" based on the most tenuous relationships. Totally ignored is the other aspect: government spends many billions of dollars on global warming research. This attracts scientists to somehow relate their research to global warming. If they find some relationship between their research and global warming, they can get more funding to explore this further. If they find none, it is much harder to get funding. It is hardly surprising then that scientists find lots of evidence for global warming in order to keep the easy grant money coming. Those who don't believe the evidence on global warming suffer from a lack of funding, and often don't publish dissenting opinions to avoid the inevitable political pressure.
This same sort of effect occurs anywhere science and politics cross, which is almost everywhere anymore.
Don't construe this as me saying science is bad: to the contrary, it is the best thing we have going and the most successful way mankind has found to gain knowledge. But most people need to understand its limits and not look at it with such religious awe.


