As a tribute I'll do 2 in a row.
I think Mr. Tyson is prone to the same emotion as Mr. Dawkins and those who wrote the scripts to the show. They know how much time and effort went in the research. They know the long road that was taken by many men and women that gives us the insight and immense benefits we are reaping right now.
I bet it's agrevating as hell when people brush it aside that easily and go: scientists predicted cooling in the 70s so they don't know what they're talking about. Especially when it's a result of organised dissinformation. Those people who get duped aren't to blame because they're victims of that dissinformation. But when there are some powerful players promoting it, then they can have an influence on policy making
So you're saying that they need to address it in order to "fight the good fight"?
Yeah, I get that I guess. It just seems so unnecessary and obtuse, not to mention detrimental to the content and spirit of the show, at least from my point of view as a Canadian, where people who believe such silly things exist for sure, but where they don't have enough voting power to enact stupid laws or have much influence. Then again in some cases there might just be enough of them, such as in the case of climate change, but I'm not sure if that particular "controversy" ever made it on the show.
I guess it's sort of depressing that he has to acknowledge those points of view as anything valid or worth discussing on a science show. In my mind it'd be like Gordon Ramsey taking some time out of his Master Chef show (or whichever one) to remind us that some people out there believe that steaks aren't real, but that for the intents and purposes of his show, we'll assume that they are.
What evidence do you need?
A testable hypothesis that supports all the evidence that exists and doesn't contradict anything we already know AND makes predictions that can be tested AND concludes that at some point in the past the Earth was all under water. You don't even need evidence for that! New evidence would help for sure, as all the existing evidence seems to point to the fact that you're wrong. But if you can form a testable hypothesis to make it all work with all the existing evidence and what we know, that'd be the place to start.
If it contradicts something we already know (continental drift, the earth is over 6 billion years old), you'd need to find a piece of evidence that contradicts that, so that we can throw "the earth is 6 billion years old" out the window and replace it with a new theory, which would need to be formulated as a testable hypothesis as well.
That's a lot of work and a lot of upturning of existing theories. You're going to be busy for the next couple years I reckon.