Are there any safety guidlines about how high you can climb a tree? For example, we have a lot of very tall pine trees where the limbs are all near the top of the tree. Obviously, if you try to climb to the very tip, some part of the tree is going to break and could cause an accident. I imagine that different factors such as the height, diameter of the tree at the height, climbers weight, wind speed, ... would all affect the safe height. Are there any guidelines to say how high would be safe or not safe?
All of the factors you listed should be considered when you're trying to figure out how high to climb. It's not necessarily true that "some part of the tree is going to break" if you climb to the very top. Pine tree breakage can happen if the tree is "too small" for the climber (according to the factors you've listed) as well as the tree's overall health. For example, do you see areas of fusiform canker (google it) on the trunk? If it's deep, that's where the tree is probably going to break in a windstorm or could break with excessive weight above it. I suggest that you read both pieces in the section "The Tree You Climb" on our website before you proceed.