The World Weave (COA)

When you cast this spell, you are able to alter the climate of a region in a 100 mile radius.  You are unable to affect land forms (such as rivers, mountains, etc.) or living things (plants and animals) directly, but you can manipulate the temperature, humidity, wind, and sunlight to whatever you desire.  While the change is instantaneous, it might take some time to affect living creatures within the spell's area (DM discretion).  For example, changing a jungle environment to a desert environment would immediately remove water and reduce humidity, but it might take a couple of days before the jungle flora wilts and dies.  This effect is permanent unless removed by a dispel magic or similar spell.