I know it's easy to blame climate change for anything and everything, but that's simply incorrect.
The actual takeaway is that our data is wrong, these floods occur more often than we thought. With only 150 years of good data, it's impossible to calculate "500 year" events accurately. You would need around 5,000 years of data to do that, and we don't have it.
So we ended up significantly underestimating how often these events occur.
You can see in graph that floods are occurring more often and that clouds are able to absorb more water as temperatures rise. This hurricane would have happened. But this flooding is worsening because of climate change that is irrefutable.
The actual takeaway is that our data is wrong, these floods occur more often than we thought. With only 150 years of good data, it's impossible to calculate "500 year" events accurately. You would need around 5,000 years of data to do that, and we don't have it.
So we ended up significantly underestimating how often these events occur.