Nobody is wrong here I feel. The recorded data set - however limited - is what we have to work with at this time. If it indicates that climatic extremes are becoming more frequent and ever more extreme, we should act on that information.

Saying climates have fluctuated since the beginning of time really means nothing scientifically speaking, as we don't understand fully when or why this happened, just that it did.

We have cold hard data for the last 100 years so that's what we should go on. If we're still around in another 100 years then we'll have double the data and a better picture. That's science!

The data tells us what's true until it tells us something else...