Final answer:
Precipitation is projected to increase globally on average but with great regional variation; some areas may see more precipitation, others less, and some may notice little change, with intensified precipitation events being common.
Step-by-step explanation:
The way precipitation is projected to change over the 21st century is complex, as it is expected to vary regionally. While the global average annual precipitation is anticipated to increase, the distribution of these changes will not be uniform across the globe. This inconsistent pattern means that while some areas may see increased precipitation, others may experience decreases, and yet others may notice little change at all. Intensification of precipitation events is likely, especially in tropical and high-latitude regions; however, storm tracks are also expected to shift towards the poles, affecting different regions in various ways. Significant changes in the seasonality of precipitation and the form in which it falls (rain, ice, or snow) will pose additional challenges across the world, potentially affecting water supply and agriculture.