Humans will freeze or starve to death and vampires will lose their food source. What was Harkon thinking?

I wondered the same thing myself. With the sun being the ultimate source of energy for life as we know it, his plan seems a bit shortsighted. Especially since the Nords hadn't quite mastered hydroponics, geothermal energy, or artificial lighting capable of supporting a continent. Then again, his plan does do a good job of giving one the feeling of "doomsday", which fits the whole "evil villian" role quite well.

well if block out the sun for a day have a feast and terrorize lol but he wanted to eternity lol his eternity will be 5 years tops when he got to fight all of the world lol

The Elder Scrolls universe would not be affected by the sun going out the same way Earth would be. In fact, if you finish the quest with the crimson nirnroot, you will get a book that actually says the sun went out for a year once. All that happened was nirnroot started disappearing. All the other plants "found a way" to survive. The sun is just a hole ripped into the realm of Oblivion from a god leaving.

You can read up some of the lore about http://www.uesp.net/wiki/Lore:Nirn and http://www.uesp.net/wiki/Lore:Mundus on those links. Also, http://www.uesp.net/wiki/Skyrim:The_Nirnoot_Missive I mentioned.

So basically, the sun has already disappeared for a full year, all it did was remove a bit of magic from the world.

I did not know that. Although "found a way" is a pretty weak explanation on behalf of the writers. It's almost like the plants are given sentient like qualities.

I guess if Harkon had the ability to make the sun come and go at a whim, the psychological control he could exert would be considerable.

Well, the eight divines had to give up parts of themselves to make Nirn, so I don't think they would let a magical connection to their plane disapearing completely destroy everything. If you look up the lore, it all makes perfect sense.

Vampires wouldn't need to feed. They feed to ward off the sun. And guess what's taken out of the equation? That's right. The whole reason for them feeding in the first place.

Which is precisely what the Moth Priest (Dexion) will say to you upon completion of the main quest (on the Dawnguard side). He flat out states that Harkon's plan was shortsighted. He also points out that everyone would have been doomed, both humans and vampires had Harkon succeeded.

So, at least one of the DLC's writers was aware that Harkon = idiot.

The only reason vampires in this game feed is to ward off the sun? It's not for nourishment as well? I wasn't aware of that. I really haven't played as a vampire though. I remember a quest in Oblivion where a guy and his wife were both vampires, he was a duke or someone with a castle, and she was in a coma from lack of feeding. The quest revolved around helping the husband and wife. Trying not to spoil anything for anyone. But anyway, I guess I'm confused.

"catastrophically affected plant life", "found a way", "climate shift".... are not good news.
It affected the life on Nirn and it was not in a good way.
But it doesn't matter, Vyrthur and Harkon are dead, end of story.

But the Dragonborn is not and removing the sun does not seem a bad idea.

Serana was locked up all that time, she seemed fine. Maybe pure blood vampires do not need to feed. Harkon did not seem to be worried what happened to other vampire groups.

I am just curious what The Elder Scrolls lore has to say about the reasons why Vampires must feed. I remember reading an in-game book that went into detail about all the different vampire groups, but I can't recall if there's anything that says why they feed and what happens if they fail to.

Didn't Serana have a spell cast on her of some type before being put packed up and put away like a jar of canned jelly?

http://uesp.net/wiki/Lore:Vampire

Sunlight is magicka, which exists in other forms elsewhere on the planet.

Plants probably found a source of magicka to photosynthesize.

That's about what Valerica's conclusion is on the whole "Tyranny of The Sun" prophecy too.

Though, her line of thought would be "Every nonvampire on Nirn now has a reason to hunt out and kill every single vampire out there", not "the cattle will all die".

The book says that many scholars rejected the idea of the sun disapearing "catastrophically affecting plant life." The other plants "finding a way" is good news because all of Nirn didn't die, and the last one says that nirnroot are especially susceptible to climate shift. It seems only nirnroot was affected, but it is possible there were other effects not known. But overall, the sun disappearing does not seem that bad. Life would still go on.

Great thread, learned a lot

This is an example of how most Egomaniacs think. They are so focused on their agenda that they don't consider all of the consequences of their foolish plans.

Well when you watch the animation, the sun isn't technically gone. So even if all that lore wasn't there, I'd just assume that specific harmful rays were blocked. It's still there, just.... red lol.

huh! According to this Lord Harkon's group are Volkihar Vampires! I was under the impression that they were just inhabiting the castle....since they were unable to reach through the ice and all that jaz. Perhaps it just a different branch of the same tree? Hmmmm...

I bet he's going to become a wealthy industrialist and block it out with greenhouse gases....

The UESP is the best site for gameplay information, but not the best for lore.
There is no indication that the Dawnguard vampires are Volikhar, the one and only reference in the DLC to them being the name of the castle.

That they live in castle Volikhar could mean they are Volikhar vampires, but it could also mean that Harkon conquered the castle on the original inhabitants and kept its name, historically its as common not to rename places as it is to do so.

The only Skyrim vampires we can be absolutely sure are Volikhar are the ones the game names so, the Volikhar and ancient Volikhar 'bosses' you can rarely find across the map.
Alas, even they never reach through the ice to grab you but hang out in caves and crypts.