Fighting climate change will require us to plant more trees. Some may calculate that the warming effects of trees are higher than that of other measures, but we believe that as long as you store the grown tree and you maximize growth of the trees you will store significant amounts of CO2. Also the secondary effects of trees, to bring shade, moisturize the air have been shown to be very effective ways of greening and cooling a region at the lowest possible cost.
The main problem is that land is usually owned by people. These people need to be convinced. So the best place to plant trees is on land nobody cares about, which is also the hardest places to plant trees. Dry and rocky regions can sustain trees, China has shown that in its tree planting project (the ‘Great Green Wall’ which aims to combat desertification). Fighting the deserts is not a choice, it is absolutely vital because if you don’t fight climate change, you lose.
Luckily there are new technologies that can help us helping trees to grow in hot, dry, rocky regions. Solar for one can help pump water and power desalination installations. Ionic desalination is much more efficient than RO desalination, and small installations can irrigate a lot of saplings. Another idea is to cover the root to retain water and protect against the sun. This can be done with small plastic cones, and in some cases with a dug in container of water.
Trees to plant are these
Trees like the Acacia can bring shade which reduces water evaporation from the soil (of course there is evaporation from the leaves).
Texas ebony tree with a dense cover.
We would not seek profit from growing trees, we would create covered areas with trees, where they are grown and cut (the wood being dumped for carbon sequestration) and regions inbetween that can become habitat for people now that the region cools. This is following the extraeconomic pattern where the trees grown are not an asset, nor they are loaded with debt from the wider economy.