claim: The divergence of tree-ring proxies from temperatures after 1960 is openly discussed in the peer-reviewed literature and the last two IPCC assessment reports.
evidence: The implications of the decline are discussed in Chapter 2 of the IPCC Third Assessment Report, and in Chapter 6 of the 2007 IPCC Fourth Assessment Report ( AR4 ) which describes discussion of various possible reasons for the divergence which does not affect all the trees, and says that there is no consensus about the cause.