I won't say who said it, but does this sound right to you? Dendrochronolgists on TV all say it so easy, you count the tree rings and the space in between, and that will tell you about the temperature and precipitation and how long the tree lived. Also: This sounds kind of dumb, but what about carbon dating? We assume the ambient carbon (or something like that) stayed the same the whole time. But didn't it change? What about between mass extinctions?