the hockey stick is about temperature, not CO2, and it's pretty shoddy. It uses current day pretty accurate data to estimate past proxies like corals and tree r

the hockey stick is about temperature, not CO2, and it's pretty shoddy. It uses current day pretty accurate data to estimate past proxies like corals and tree rings. But it combines all of them in a graph that is not really accurate. Much better temperature reconstructions have been made available.