I believe we are witnessing climate change. Yes, it is true that weather fluctuates and even climate has changed over the eons. But weather refers to short term conditions; climate to long term ones. And those long term ones become the norm over the course of millennia, not in the 150 years or so since the beginning of the Industrial Revolution.
Extremes of high and lows temperatures have increased and so have the frequency and severity of “weather events,” such as hurricanes and tornadoes, droughts and floods.
I am a birder and a gardener and have empirically observed (is that a tautology?) changes because of climate change. For example, 25 years ago, it used to be a big deal to see a Black Vulture here in So. Jersey; now I see them frequently all year. And I put up my hummingbird feeders earlier in the spring and remove them later in the fall. (“Hope is the thing with fathers.” – Emily Dickinson.) Plus, our frost-free date is earlier and first frost date later. I have roses still blooming, milkweed seeds germinating, and hibiscus and goldenrod blooming simultaneously.
The “new normal” is in constant flux.