If multiple planets or moons undergo similar changes together, the cause is certainly Extra-terrestrial (be it Solar, Interstellar, or Galactic).

We need to understand naturate climate cycles and the range of variability, so that we have a good forecast of what the future may be like. We actually have a good handle on past cycles from the Greenland ice cores and other historic/geologic climate records and proxies.

In theory, if we understand the drivers of climate, we can take appropriate action to ensure that sudden change is avoided and we go to neither ice age nor hot-house.

One danger with the current CO2 concentration is that there is a clear past link between CO2 and global surface temperature. It is less clear WHICH is the driver and which is driven (and indeed there may be lements of both, multiple feedback cycles, different timescales etc.). What IS clear is that we are in a realm of atmospheric CO2 concentration. that has not existed at all for the last several million years.

Does this matter?

Well, that's the 64 gazillion dollar question. I certainly don't know the answer...