There are now two very good reasons not to watch the video: 1) the lecture is by a dishonest man and we are being asked to trust that his models and judgement are accurate, and 2) it's most likely that the video was posted for a political agenda and not scientific or technical edification.
An "echo chamber" when it comes to science usually means that things have been mostly figured out correctly. An "echo chamber" for political discussions is where it could be considered a bad thing.
On the matter of AGW, we have the situation where the science is not separate from politics because there is a strong push by many people to use the power of the state to impose changes on people and companies in the name of AGW mitigation.
The fact that there are huge amounts of money that could flow into the coffers of heavily debt burdened western governments should make you pause a little to consider how this money may bias the science.