More and more, truth is treated as relative. Each person is thought of as having their own truth. While this may be useful for emotional response or philosophy, it can cause real problems when speaking about matters where there really is one truth.
For example, I see people all the time who believe what they want, even when faced with overwhelming evidence to the contrary, because they were taught that truth is relative. If a scientist is presented with facts, then they must adapt to those facts rather than ignore them in the face of their own agenda. If rainfall is higher than previous years in a given area, for example, then it would be insane to claim that it is dryer! Or if the actual temperatures of each day of the winter have been five degrees cooler, then it doesn’t make sense to say the winter has been warmer.
People, both scientists and professors and laymen, often believe things despite evidence to the contrary. Truth is not relative, it is absolute. Perception is the only thing that is different. What are some examples you can think of?