The red “comet” may not be a comet after all but a meteor that falls down and crashes into Planetos bringing the Long Night.
“In ancient books of Asshai it is written that there will come a day after a long summer when the stars bleed and the cold breath of darkness falls heavy on the world. – Melissandre, ACOK
Falls heavy? Hmm…The star bleeds and then falls bringing the cold and darkness.
When we see comets with an enormous red tail, that may signify they are breaking through the atmosphere and burning.
GRRM told us that the seasons have a magical root. Perhaps some magic, the Moon Singers or the Others perhaps have a spell to bring down a meteor. The reason I mention the Moonsingers is because they are based in Braavos and the FM of Braavos are implicated in the Doom of Valyria.
Once the meteor hits land on Planetos and that could be on the other side of the world, it would send up astonishingly large plumes of debris that can block out the light.
“The impact of large meteors on Earth could also cause climate change. The impact of a meteor would send millions of tons of debris into the atmosphere. This debris would block at least some of the sun’s rays, making it cold and dark. This climate change would severely limit what organisms could survive. Many paleontologists believe the impact of a meteor or comet contributed to the extinction of the dinosaurs. Dinosaurs simply could not survive in a cool, dark climate. Their bodies could not adjust to the cold, and the dark limited the growth of plants on which they fed.” – National Geographic
The Song of Ice and Fire is built on the conflict of light vs dark. Ice vs fire. The Lord of Light vs The Great Other. But there is another great battle that gets less attention. Air Vs. Water.
Air = Old Gods + Storm Gods.
Trees make the air, symbolized by the Old Gods and their Wierwoods. Trees need watering (but not too much). The Stormgods bring the rains which nourish the trees that bring the air.
Water = The Drowned God / Great Other.
We have a millenia-long friendship between the North and (the descendants of) the Stormkings (Baratheons). Brandon The Builder helped build Storms End. Robert and Ned are best friends who caste down the Greyjoys, the Drowned God champions multiple times.
Together Ned and Robert, The North and The Stormlands combine to create a WinterStorm. Think about what is happening now in Winterfell as Stannis, last male heir of the Stormking blood is marching to take Winterfell.
The Winterstorm is focused on taking out the power of the Drowned God. But now that there is no one of Stormking blood in the Stormlands (sans Gendry who I think will inherit it eventually by Stannis’ decree after Shireen is killed). Now without someone of Stormking blood to challenge Euron, the Ironmen will rise up stronger than they have done before and take hold over The Reach and Stormlands.
If the Long Night winter stems from the debris from the “Red Comet” meteor crashing into the planet, then it will be the magic we think of as being of the Storm God who will be the one who, combined with The Lord of Light… ( See my post on Jaime Azor Ahannister) with the power to cast down torrential rains that may flood out the particles in the air causing darkness.