Near the equator and along some coasts cool water ascends, together with the thermocline. This paper discusses on this phenomenon, which plays an important role in climatic change. The observed facts indicate as follows: a) A positive correlation between equatorial sea surface temperature and atmospheric content of CO₂ and H₂O, b) a negative correlation between the intensity of trades and equatorial (plus coastal) sea surface temperature, c) a negative correspondence between the intensity of the trades and the latitude of the subtropical anticyclone at the both hemispheres, d) a negative correlation between the tropospheric temperature difference, equator minus pole, and the latitude of the subtropical anticyclone, and e) a negative correlation between global temperature changes and the tropospheric temperature difference, equator minus pole, which is caused by the snow-ice-albedotemperature feedback. A hypothetical hemispheric climatic feedback mechanism is, in the case of cooling after a cluster of volcanic eruptions: meridional temperature gradient will become greater, latitude of the subtropical anticyclones become lower, intensity of Hadley cell winds (trade) increases, equatorial sea surface temperature becomes cold, atmospheric content of CO₂ and H₂O becomes lower, thus resulting in further cooling. In the case of warming during a prolonged lull of volcanic activity, the tendencies mentioned above are opposite. This feedback mechanism changes drastically frequency and intensity of equatorial and coastal upwelling. Since the oceans are closed basin and the turnover time of thee deep ocean may be in the order of 500 years, the efficiency of the process is limited in the time of several centuries.