Sand & Storm. Moonfire Trilogy, #1

The entire world laid to waste. There are no second chances. The ancient machine that produced icefire was destroyed twenty years ago, but the deadly magic is again on the increase. No one understands why or where it's coming from. Massive changes in weather patterns plunge the northern half of the inhabited world in deep drought. People are once again fleeing, but nowhere is safe. King Isandor sends people to investigate a concentration of icefire in the mountains at the border, but two consecutive patrols both vanish.
It appears that, after having suffered badly in wars, the neighbouring country Arania is on the offensive, and is using icefire as weapon. Their culture is harsh and their barbarism knows no boundaries. Meanwhile two young meteorology students make a string of discoveries that will change the way the people understand the world. They're on the threshold of the age of enlightenment, but vital knowledge necessary to save their world may well get lost when war overruns the inhabited world.