detection and attribution

There have been numerous comments and inquiries about this statement of Myles Allen and myself: in our nature-online piece (no longer freely available): "The e-mails do not prove, or even suggest, that the main product of CRU, namely the record of global surface air temperature based on thermometer readings, has been compromised. Indeed, the thermometer-based temperature record has been verified by results from other groups." I want no to take the opportunity to explain my arguments. These are my arguments.