It used to be that we didn't expect anything to happen to the climate. It wasn't something that we expected to change. Weather normally changes from day to day, but climate was expected to stay the same from one year to the next. So in that sense, yes, you're right. Anything that happens to the climate is proof of climate change, and climate change of any sort is bad news for the planet and its many life forms.
However, we now have a pretty definite indication of
how the climate is changing, and yes, it's complex. Like evolution, the debate was over a long time ago about whether or not it's happening. The only controversy among the scientific community today is in the details.
About the myth that scientists predicted global cooling in the 1970's:
http://www.google.com/search?hl=en&q=global+cooling+1970's&aq=3&oq=global+cooling&aqi=g10