Water mixes down into the ocean depths in only a few very cold regions, such as the Atlantic south of Greenland and the Southern Ocean near Antarctica. In these regions, warming will be delayed because much more water needs to be warmed up to get the same temperature change at the surface. Aerosols may counteract some of the effects of greenhouse warming in the vicinity of major industrialised regions. Clouds of superfine sulphate particles from burning coal and oil should counteract greenhouse warming over much of the Eastern USA, Eastern Europe, and parts of China. But since some action is likely to reduce sulphur emissions because of acid rain, the size of this effect is unpredictable.
Total precipitation is predicted to increase, but at the local level trends are much less certain.
Wintertime precipitation in the far north is likely to rise, but what happens in mid-latitudes and in the tropics depends very much on the details of the particular climate model and the emissions scenario. Including the effects of aerosols, for example, significantly weakens the Asian summer monsoon in the two models which have so far run this experiment. More rain and snow will mean wetter soil conditions in high-latitude winters, but higher temperatures may mean drier soils in summer. Local changes in soil moisture are clearly important for agriculture, but models still find it difficult to simulate them. The frequency and intensity of extreme weather events such as storms and hurricanes may change.