In between the two extremes of where planting trees is highly suitable and areas where it is not, it is important to remember that the context matters and that decisions to forest should look beyond simply the act of planting trees. We can consider what the ecological, social and economic goals are of tree planting. It is then important to verify the local context and decide what restoration action will be most effective. It is also more efficient and effective to conserve existing forests before worrying about reforesting.
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report