Climate change and national security.

Then NASA chief James Hansen outlined the state of global climate change research.

Watch the video here.

In late 2005, however, Dr. Hansen’s ability to voice his concerns about global warming was severely compromised by NASA public affairs officials.

After he called on the United States to reduce greenhouse gas emissions in a December 2005 lecture, Dr. Hansen found that NASA officials began reviewing and filtering public statements and press interviews in an effort to limit his ability (as well as that of other government scientists) to publicly express scientific opinions that clashed with the Bush administration’s views on global warming.