All of us have a God in us, and that God is the spirit that unites all life, everything that is on this planet.
When resources are degraded, we start competing for them, whether it is at the local level in Kenya, where we had tribal clashes over land and water, or at the global level, where we are fighting over water, oil, and minerals. So one way to promote peace is to promote sustainable management and equitable distribution of resources.
For me, one of the major reasons to move beyond just the planting of trees was that I have tendency to look at the causes of a problem. We often preoccupy ourselves with the symptoms, whereas if we went to the root cause of the problems, we would be able to overcome the problems once and for all.
We are very fond of blaming the poor for destroying the environment. But often it is the powerful, including governments, that are responsible.