The bad part is that the oceans are not just water, they are complicated biogeochemical systems that influence everything.

The oceans play a vital role in the carbon cycle due to a biological pumping action that pumps nutrients and carbon up and down. Climate change distrupts this process, it causes thermal stratification, which causes nutrition deficiency, which changes the plankton (including bacteria and algae) mix you get, which changes everything, but especially the atmosphere.

So it's not just water, our oceans are what makes Earth habitable. They are way more important than any stock market, and we should pay a lot more attention on them. All the attention really, we should just have an economy where performance is tied to how the oceans are doing.