In recent years the climate has been generally cool in northern Asia  But during periods when the average daily temperature and humidity in northern Asia were slightly higher than their normal levels the yields of most crops grown there increased significantly  In the next century, the increased average daily temperature and humidity attained during those periods are expected to become the norm
Yet scientists predict that the yearly yields of most of the region' s crops will decrease during the next century
The climate in northern Asia has generally been too cool and dry in recent years for populations of many crop insect pests to become established.