It would take a global conspiracy of scientists for falsified data -- and the conclusions drawn from it -- to survive for very long. Scientists are (only) human, and suffer from all the same faults you can see in any other profession. There are significantly more honest scientists than dishonest ones, though, and as a group they have their sights set on discovering, revealing, and explaining the mechanisms that make the universe tick.

Truth is the goal, and the scientific method is the best tool humans have ever invented for getting at truth.