If you think that a tree poses a risk to people or property, then you should contact a qualified arboricultural consultant or tree surgeon to assess that risk. If the tree is on your land, you are responsible for ensuring that the tree is safe and if it causes damage to a person or property then you may be liable. If the tree is on someone else’s land, you should contact the owner of that land to make them aware of the potential risk. If you are unsure who owns the land that the tree is on, you should contact the local council for where the tree is located.