Are the global climate changes cause for alarm?

I have been reading Climate Courage by Andreas Karelas upon finding it at a bargain store. This matter of global warming I had come to believe was something which has been blown out of proportion by the media. Could it be a collective hallucination that human industry is causing all these environmental changes? I have a feeling many want to deny the harmful effect humans have on the environment as it's too much of an inconvenience for them to think otherwise. On the other hand, I have been persuaded that some environmentalists are fabricating information to create a sense of alarm. Carbon dioxide has been this great obsession when it's not truly a toxin and I have yet to see any clear evidence that it's worthy of all the media attention and alarmist propaganda about how it's harming the global environment.