Toward Ecosophy

Yes. The meditations that are potentially dangerous are the ones that move subtle energy within the body; you're dealing with the life force when you do that, and if you mess up you can screw up the balanced flows that keep you alive. Certain practices are known to be safe -- the Middle Pillar exercise used by the Golden Dawn and the Three Cauldrons exercise taught in several of my Druid books are examples of these. If you have any doubts, find people who have practiced them systematically for at least several years and ask about their experiences.