Hot sour and empty can't sustain the 3 billion humans currently dependent on the world's marine ecosystems for their livelihood. What will they do? Where will they go? Will we wonder why we batted an eyelid at the current refugee crisis once the dead zone in the middle of the Bay of Bengal starts to cause displacement of the 200 million people dependent on that area? - https://www.theguardian.com/environment/2017/jan/31/bay-bengal-depleted-fish-stocks-pollution-climate-change-migration
Taking out sharks isn't the only cause of all this. We are. With our thoughtless lack of regard for, and normalisation of, the harm we cause in our everyday lives. And the way our societies are hardwired to prioritise financial growth above all else.
But one way to speed things up so that you'll get to see global devastation yourself and it won't just be something your children will have to face after you're gone, is to get rid of the apex predator of the most biodiverse ecosystem with the biggest impact on climate and weather on the planet.