Effectively, eight seperate committees (House of Commons Science and Technology Committee (UK), Independent Climate Change Review (UK), International Science Assessment Panel (UK), Pennsylvania State University, United States Environmental Protection Agency, Department of Commerce (US), and the National Science Foundation (US)) assigned to investigate the issue determined that there was no evidence of fraud or scientific misconduct.
Again, if evidence is advanced that stands up to scrutiny which shows climate change doesn't exist or is not man made then our current understanding will change based on the new facts. That just hasn't happened yet.