The Wasting (EAFW)

To the elemental beings of the inner planes, the raw condition of natural elements on Athas is fodder—food and sustenance. The earth provides the inner planes with power as precious water, mighty winds, and all-consuming fire feed their own. On most worlds, these elements are plentiful and rich, and the elemental creatures are well fed. On Athas, while most of the elements can still be found in abundance, they are barren and lifeless, like the heart of a sorcerer-king. Imagine being given a choice between a stale loaf of dried bread or a piece of rich, moist cake. This is Athas today compared to the world it once was. It is not hard to understand why elemental spirits are upset with the meager fare being set before them.
The Plane of Fire celebrated when flames consumed vast forests or the mighty cities of mankind on Athas, and its denizens drew their energy from the massive destruction and purification of the cleansing inferno. Now, Fire is afraid to consume what remains for fear of depleting these reserves forever. The power that once consumed anything in its path now lives in tiny campfires, frantically trying to escape these maddeningly small prisons.
The Plane of Air has also suffered from the Wasting. Cool breezes once circled Athas in constant song. Racing through green trees and up valley walls, air lunged from terrific oceans to form terrible typhoons. Now, the once magnificent wind sighs lethargically in the still heat, and only rarely does it scream its rage in a violent sandstorm of destruction. Where once the wind sang of its freedom, it is now a harbinger of doom—Athas's doom.
To earth elementals, the rich soil that once fed their plane with power was beyond imagining. Today, the lifeless dust and sun-baked rock is little more than prisoners' fare. The Plane of Earth still draws immense power from the towering peaks and vast expanses of desert that cover Athas, but even that power is a meager fraction of what it once was.
Of all the elementals, the Plane of Water has suffered most. There are scant few havens in which this element can be found in any quantity. Some say that mighty waterfalls once poured over Athasian soil, and that the elementals which drank of this power were the most carefree and content of all. Now, these beings are much more grim, more desperate, and vengeful than their happy, babbling ancestors. Power for the Plane of Water lies in isolated pockets of stagnant liquid, constantly in danger of the encroaching silt and the relentless sun.
Unfortunately, the remote and chaotic elementals realized Athas s impending doom far too late. Most sages agree that the planet's spiralling decline has become irreversible.
Regardless, these beings have deigned to forge a pact of Earth, of Air, of Fire, of Water, with a few selected beings of the Prime Material Plane. Through these few clerics and druids, the elemental powers hope to replenish the decaying planet of Athas and return to the ancient, carefree days of power.