Should we use GMO trees to slow climate change?

How about financing the turning of the Humboldt Current (that ecosystem) into an international wilderness reserve? (With "almost-no-touch" policies - with the exception of non-lethal tinkering with algae to be more productive - so producing more sardines - so feeding more whales, so producing more whale turds falling down into a subduction zone, and destined to be incorporated deep in the Earth's mantle in geological time.)

You could interfere lethally with something like algae. Imagine that someone finds a brilliant way to produce hydrogen by algal photosynthesis, modified. That would save the Earth, right? Only if the algae escaped, we'd be looking at higher hydrogen levels in the atmosphere (although it apparently "boils off" into Space, so it might just begin an endless shrinking of the Oceans). Nice little apocalypse, I think?

But back to Humboldt. If, instead of fishing where we "regulate" right up to the very limit of a prey species population collapse point, we just left all those "resources" (fellow living creatures we share this Planet with - living things in a mainly dead Universe) to just live (with perhaps a bit of help) what would the impact be? Your algae would mainly fast-cycle, but there are parts of that ecosystem that "deep cycle"?