I saw an interesting video a while back about a hypothetical mega-project to turn Sahara into a forest.
The conclusion in that particular video is that it would actually make global warming worse for two reasons. One is that forests reflect less light than desert, and second is the enormous amount of energy required in producing and distributing water in the enormous desert.
But that doesn't necessarily mean that growing forests in more suitable places is a bad idea. Humans may not be very good at planting forests though. The "Green Great Wall" of China suffers from biodiversity problems, as do the forest planting projects of my native Norway.
Land owners have for decades been encouraged to plant pine trees, because they have economic value. The problem with that is that pine forests suffer from very low biodiversity. Simultaneously forests are growing all over the country because of depopulation of rural areas (and, ironically, because global warming lets trees grow in areas that were previously too cold).
I guess what I'm saying is that the whole issue is a bit more complex than The Independent explains it.