Elizabeth I
Philosopher
We have quite accurate records from several tens of thousand of years, and less accurate ones from earlier than that.
If you don't know how, I suggest a little research.
Do you know the difference between weather and climate? If not, I suggest you do a little research in a dictionary or a 7th-grade general science book. The weather changes all the time. We have records about climate (plant fossils, glacier ice core samples, etc. - yes, I do know how.) We do not have any records about a temperature variation of a few degrees over a few years from 10,000 years ago, and not any accurate ones from 1,000, 500, or even 300 years ago.
While the data currently being collected may be accurate, until we have seen a consistent trend over more than a few decades, I submit that we cannot possibly know if they actually signal a climate change. I'm not saying they don't, I'm just saying that observations over our pitiful 70-odd years of life are pretty insignificant compared to the history of the global climate.