> Could we engineer a more efficient photosynthesis?

Yes! They’re called solar panels, and our best ones are about 4x more efficient than the most efficient photosynthesis processes in nature, afaik.

A tree grows a leaf slightly more efficiently than we create a solar panel though.

Solar panels so far don't remove CO2 from the air, though.

You can connect them with other equipment to do that, if that’s your goal. Not very effective though

The removal is only temporary.

Can be a couple of hundred years with trees and wood used for housing. Long enough to figure things out

Not if the panels were to produce graphite pellets that people could bury or dump in ocean trenches.

We both know people would burn graphite pellets. That’s what we do with wood pellets today.

I see that as a positive, not a negative. Since the pellets can be sold, investors are more likely to invest in the development of the process. And the extra volume of production tends to increase the efficiency, i.e., to reduce the cost (paid by altruists and governments) of producing the pellets that do end up in the ground or in ocean trenches.

It might actually help with financing the things. I guess it is almost carbon neutral. Zero efficient though.

That’s what I’m using as the benchmark, but I was thinking more like bio engineering to create an organism that gets closer to solar panel efficiency.

Would be potentially very useful for timber or biomass production. I doubt people would trust eating it.

> Evolution ... improve[d] on photosynthesis

Evolution simply describes the macro process of death and birth as affected by the environment, no improvement planned. It could well be that a certain set of traits survive purely by chance or slightly improved odds in one set of circumstances that are detrimental later.