The Crowfall site has an exciting new article that details one of the game's most exciting features: The Hunger. "The Hunger is a dark, supernatural phenomenon of unknown origins" the post reads. "It spreads across the land like a pox - a nocturnal disease that affects the land, the trees and every living creature it touches."
The Hunger operates on a cycle of time that is marked through a day / night cycle as well as a seasonal cycle. The Hunger comes into play in two different ways: "as a contagion that infects the world" -- literally destroying it over time --; and as corruption of creatures that live on the planets it is infecting.
As a planet becomes infected, large black "living" crystals appear that literally suck life and warmth from the ground on which it sits. Each day more appear in random locations that are immediately recognizable due to falling snow surrounding the crystals.
Players will have an opportunity to destroy the infection, though not permanently. The infection will return. But there is a benefit: Destroying crystals sometimes yields Hunger Shards.
The one benefit to the proliferation of hunger crystals is that players can sometimes find valuable hunger shards within a demolished crystal. These are useful in crafting and are necessary component in starting a siege (by planting a Banewood tree).
These cannot be collected from any other resource.
Of course, with the infection comes the corruption of the beasts inhabiting the planet. It changes them on a fundamental level making them stronger, gives them different abilities, and makes them "aggressive and ravenous".
You can learn more by heading to the Crowfall site.