A fair point. When you review the show notes for pre-BNW, you will likely find at least some parts in many episodes that are still relevant and likely of interest to you. Even if you find few or none of those episodes worth listening to in their entirety for yourself in the present day, I expect that you will find parts of some-to-most that are. You may have a 'limit' back to those when CivV was first discussed in part, but that would still give you more than two years' worth more content to peruse.
I'll try some Dan.
About global warming, I never played Civ IV (only Civ II, back when Elvis was one of my ministers and decorating the throne room was a thing). But the way you guys talk about it, seems that the mechanic was broken.
Without knowing that, when I started playing Civ V, I remembered that in Civ II late game some tiles got polluted and you had to send your worker (engineer) there to fix it. So I thought that Global Warming would be a way to bring pollution back to the game, with a economic focus: the global carbon credit market. Some things came out of that:
-new world congress enviroment-friendly act, for example forcing players to upgrade factories or build buildings that annul units emissions, and/or creating the carbon credit market)
-carbon credit market would take some gold from the ones that pollute more and give to those less "industrialized". Or would take some gold from everyone (depending on there contribution to global warming), so that the UN can use these resources to "fix" global warming.
-game saves pollution modifiers (oil and coal-base units movement, number of factories, nukes)
-enviromental-friendly AIs get minor positive/negative diplomatic modifiers depending on your contribution to global warming
-global temperature increase (begging in atomic era): in higher levels causes some ice tiles to melt and in extreme levels causes sea level to rise, transforming some flat coast tiles (non-hill or mountain) in coast tiles. Desertification too.
-just like from some times we get those rankings(someone publishes a work that is the rank by techs or something), there could be a publication saying "scientists say that at the current pace, if nothing is done, the tile west from your capital will become a desert (or will be swallow by the ocean)".
-research labs or other buildings could stop the global warming effects inside the cultural borders.