Been paying attention for the last decade? Noticed the record droughts in the Amazon River Basin or hundreds of thousands killed by the worst tsunamis in 700 years?
Whether humans are the primary cause or not, this is climate change, and its nothing like the pleasant Hawaiian vacation you seem to imagine it to be. I don't see the bright side.
I understand our best forecast is that the enhanced greenhouse effect will increase global rainfall.
The local effect in the Amazon river basin is just as likely the result of local deforestation as the global carbon dioxide level. As someone else pointed out Tsunamis are known to be caused by earthquakes not weather. So it seems that your examples may not the best ones.
Now the effect of rising sea levels on my pleasant vacation on a pacific island is much less in doubt, some low lying areas will be underwater if the Antarctic or Greenland ice melts, which seems like it will take quite a while.
The greenhouse effect makes the biggest difference at the poles in the coldest time of the night. So people will be able to live and farm further north in Russia and Canada.
The cost of global warming seems to be about the cost of change, and the cost risk, rather than the cost of a definitively less hospitable climate.
Paying attention for the last decade includes a cooling for the recent past associated with short term patterns. Global warming is not about the cost of what we have seen, it is about what we will see if we emit CO2 at various levels in the future, which we don't know. And not knowing is not a reason to do nothing, but it is also not a reason to claim calamity is certain.
Whether humans are the primary cause or not, this is climate change, and its nothing like the pleasant Hawaiian vacation you seem to imagine it to be. I don't see the bright side.