Leonard Ornstein is all over the news today, with his plan to reforest the Sahara using desalination.
There are predictable knee-jerk rejections of the plan, but it is certainly worth piloting, as an experiment. I have been advocating this for a couple of years now.
Ornstein's proposal to use Eucalyptus is dubious, as it is invasive, and some species are toxic to flora in their vicinity. They also have very deep roots, and an extensive euclalypt forest could conceivably have the effect of lowering the water table. I was a trustee of Tree Aid years ago, and we had a successful stand of eucalypt. When they were harvested, the local stream, which had mysteriously dried up, began to flow again.
It is mandatory to use native species, and the planting should be to the advantage of, and using the labour of, local communities, rather than some kind of post-colonial industrialisation.
Community forests would probably bring the costs down too. The planting should begin at the coast, and work inland from there. East Africa would be the place to start, in view of the drought there. The work would also help to bring peace to Somalia.
The basic reaction to any of this carbon sequestration stuff is "We shouldn't be putting CO2 in the air in the first place. Sequestration is a Moral Hazard!"
The answer to this objection is that it is possible to walk along and to chew gum at the same time. We need BOTH decarbisation AND sequestration. The 40 year time lag means that even if we could magically stop CO2 emissions today, we would still need sequestration to avert disaster.
So, no brainer. Forget Ornstein's $trillions, forget eucalypt, forget industrial forestry, remember the people, and let's start planting forests aap.