We have a list of the Popular People Great Ideas. This one goes up against seeding the oceans with iron, putting sulfur dioxide in the atmosphere, and getting rid of natural gas.
In the article they caution that their magic trees may need fertilizer and more water. Really? The best idea for the destruction of the Earth is tinkering with photosynthesis.
If you like physics, then you know that plants came up with the great idea of zapping CO2 with photons to produce O2. This was a couple of billion years ago when the atmosphere was all methane and CO2 replacing the current O2 percentage. The nitrogen was always the same.
Oxygen was a horrible pollutant. It kills all the anaerobic bacteria, but the careless green things (cyanobacteria at the time) didn't give a hoot. All's fair in war, the Russians tell us. They put out the oxygen with tremendous efficiency. Then plants came with more efficiency.
Oxygen went up to the current 20% or so. The plants could probably go up to 30% or more, but they didn't. They recoiled from that goal, and put all sorts of brakes on the photosynthesis process, the brakes that the pp's want to remove.
Why? What is it about evolution that makes it smarter than any of the pp's? A great mystery that pp's cannot explain, and I leave it at that. But they still want to muck with the Earth's current steady state, without any grasp on physics.
I've written about this before. Just be glad that no idea from the pp's has ever been practical or ever worked.