I am not sure whether agroforestry can help in climate change any better than traditional forest farming, except in its deliberate combination of woody perennials with agricultural crops or animals on the same piece of land/ It is the area of trees that play a crucial role in climate change mitigation.
Trees accumulate CO2 and provide shade against heat, not just for people, or animals, but for the plants for the trees shelter the crops against the harmful effect of raging storms. The worst environment is miles of desert that provides nothing for any living element.
Agroforestry is a practice of ecologically sustainable land use/ It maintains and increases production by combining food crops (annuals) with tree crops (perennials).