DAR ES SALAAM, Tanzania, August 24 (IPS) – For pastoralists in Arvaikheer — a village in Mongolia’s dry central plains — rain can determine whether there is enough grass for cattle to roam, whether waterholes are replenished and whether families make it through another dry season. But as climate change makes rainfall increasingly unpredictable, even a wet season may no longer provide water and pasture needed to sustain people and livestock.