Except for fish I guess

A carbon tax. Electric cars.
The climate changes less.
We’ve done it folks. We’ve saved the world.
Except for fish I guess.

Should I ascend the ranks of wealth,
And join the nouveau riche,
I’ll miss nought from my former life,
Except, I guess, for fish.

In years to come, the food runs out,
The world is on the brink.
Eight billion screaming mouths to feed,
And fish have gone extinct.