Over the past two decades, yes. But humans have been in California for a lot longer than two decades. Over all the time humans have been in California (which is basically since the last Ice Age at least, possibly longer since we don't know exactly when it was first settled by Native Americans), what we're seeing now is probably well within the range of variation. We can't know for sure because we don't have 12,000 years worth of records to tell us.
Which means we don't have the basis for saying that what's been happening in California over the past couple of decades is an emergency. It might just be part of the long term cost of choosing to live in California.
Yes, but this is the same argument people make about how you can’t attribute a given hurricane to Climate Change (although science has becoming more capable of those kinds of attributions in recent years).
Yes, climate fluctuates. Yes, there have plausibly been years of drought and fire in centuries past that would rival recent years. But absent the specific data you say is lacking, if you believe that climate science is generally correct, then more drought, more warming, more fire is the obvious trend. Not just California, but the entire world.
Regardless of whether similar events have happened in the past, there’s an obvious reason for the dramatic uptick between the 1970s and today: CO2 in the atmosphere, put there by humans.
> there’s an obvious reason for the dramatic uptick between the 1970s and today: CO2 in the atmosphere, put there by humans
The fact that this reason is "obvious" doesn't mean it's correct. Climate models based on the assumption that human CO2 emissions are the primary cause of warming have been significantly over-predicting warming. So I don't think we can say human CO2 emissions are the primary cause. We are still too uncertain about how the climate works for that.
Which means we don't have the basis for saying that what's been happening in California over the past couple of decades is an emergency. It might just be part of the long term cost of choosing to live in California.