I finally watched a thing I linked to. My bad on the slow media review. Sorry for the lots of text.

1:06 Al Roker, not a scientist, says in a video clip:
"Is it a natural cycle? Is it due to human interference or human conditions that we have created? That remains open to debate. But there is no doubt the climate is changing."

The quote is out of context so I have no idea what he's talking about. But if he's talking about recent global warming, then there is no debate. Recent global warming is anthropogenic in cause, with extremely high levels of scientific confidence behind that statement. Pretending otherwise is not helpful.

1:42 David Gregory says:
"Skeptics say the forecasts of doom and gloom are overblown"

Is that where this "debate" between Bill Nye and Marsha Blackburn is going to go? On whether AGW (anthropogenic global warming) is going to be CAGW (catastrophic anthropogenic global warming) or not? If this was an actual debate, then CAGW would be defined straight-off, and then one side would argue Yes and the other would argue No. Will such a definition occur?

1:47 Patrick Michaels, actually a scientist, says in a video clip:
"After you adjust for the fact that there's so many more people living in so many more places, there's no change in weather-related damages."

Dr. Michaels is making the claim that weather-related damages only appear to be more prevalent because humans live in higher densities and across more of the Earth's surface than (insert time here). So his argument is that the (to pick one thing) frequency/extremity of droughts isn't increasing, what is increasing is human ability to suffer from droughts and the human ability to notice.

Obviously with more people extreme weather events cause more damage: a drought hitting a country of 5 million people causes more damage than one hitting a city of 1 million. So he's couching his claim in fact. But the other half of his claim only is true if ways of detecting previous weather calamities do not exist. For droughts, tree-rings, pollen counts, lake sediments, animal sub-fossils, etc., can be used to determine whether modern events are bigger/more frequent than previous events. Scientists can state that, for example, the current drought in California is the worst in 5 centuries. Dr. Michaels, having a PhD in ecological climatology, has to be aware that such paleoclimatic indicators exist.

2:36 David Gregory asks his two guests:
"In this moment of, this kinda extreme weather moment, is it creating new urgency to act?"

Huh? Act on what? Mitigating warming or adapting to it? Nye answers this question well given how poorly worded the question is. Rep. Blackburn urges looking at the information we get from climate scientists [climatologists say that we should dramatically reduce carbon emissions ASAP], and then says that there is no agreement on whether global warming is man-made [this disagreement is nearly at nearly a 1:50 ratio], and then says that no one single weather event can be blamed on climate change [because weather and climate are different]. So cost-benefit analysis [all of which say that adapting+mitigating is cheaper than adapting more later], and looking at the US impact in a global environment [the US, historically and currently, has emitted/is emitting a gigantic amount of carbon].

4:25 David Gregory can not ask a question very well. Bill Nye argues that scientific uncertainty is not the same as uncertainty about entire scientific ideas.

6:15 Marsha Blackburn claims that atmospheric CO2 levels have gone from 320ppm to 400ppm. She meant to say 280 -> about 400. And then she says that a 25% increase over two centuries is "very slight". Rep. Blackburn cites Lindzen and Curry as people who reject AGW. ...except that Curry doesn't reject AGW. Mr. Gregory interrupts to point out that two scientists are not equivalent to hundreds of scientists who disagree with them.

7:35 Rep. Blackburn argues that US emissions being cut would not actually affect global emissions, which is ridiculous and pretends that one country's energy policy changes would not affect those of other countries. Also she has no idea what is the difference between a hypothesis and a theory and thinks that science can be proven.

8:50 Mr. Nye claims atmCO2 has gone from "250 to 400" since 1750 which is also wrong. ... :-/ Mr. Gregory interrupts.

9:50 Rep. Blackburn mentions more cost-benefit analyses. Claims there is a lot of ambiguity over the "social costs of carbon". Claims that increased carbon leads to increased agriculture production [only true if other limiting factors are allowed to be unlimited].

12:50 Rep. Blackburn claims Congress has acted on carbon emissions. ...yeah, all in ways that do nothing to limit carbon emissions. Cost-benefit analysis! Also claims carbon emissions are at the lowest they have been since 1994. Does she mean globally? For the US? Apparently she meant for the US.

Overall, this was an awful discussion that didn't qualify as a debate because a central thesis was not defined. Bill Nye argued that anthropogenic global warming is real, is happening, and helps cause weather-related disasters. Rep. Blackburn argued that scientists aren't convinced AGW is real, and that any attempts to control carbon should engage in cost-benefit analyses.

But the Congress she is part of ignores cost-benefit analyses which state, clearly, that increasing atmospheric CO2 causes more costs than benefits.

Also, if this was supposed to be a "debate" on the economics of global warming mitigation, then why invite in two non-economists to talk? Oh wait, I guess Rep. Blackburn could be an economist, because she acquired her B.S. in home economics.