Finding no research misconduct or other matter raised by the various regulations and laws discussed above, this case is closed.
The NSF also studied the university emails related to "climategate" and found "nothing contained in them evidenced research misconduct within the definition in the NSF Research Misconduct Regulation." Penn State's earlier investigation concluded (pdf available here):
"An Investigatory Committee of faculty members with impeccable credentials” has unanimously “determined that Dr. Michael E. Mann did not engage in, nor did he participate in, directly or indirectly, any actions that seriously deviated from accepted practices within the academic community for proposing, conducting, or reporting research, or other scholarly activities.” His work “clearly places Dr. Mann among the most respected scientists in his field…. Dr. Mann’s work, from the beginning of his career, has been recognized as outstanding.“