Pacific trade winds can affect global temperature

Ars Technica : Despite the dearth of instrumental data until recent decades, Diane Thompson of the National Center for Atmospheric Research and her colleagues have been able to reconstruct climate variability in the Pacific Ocean through the study of the concentric rings of coral’s calcium carbonate exoskeleton. According to their study published in Nature Geoscience, when ocean sediment gets stirred up, manganese can get incorporated into the coral. Such stirring up primarily occurs when easterly trade winds are at their weakest and the wind blows from the west. By measuring the ratio of manganese to carbonate, the researchers were able to determine which way the wind was blowing and when. According to their findings, the period 1910 to 1940 saw weak trade winds, whereas the period 1940 to 1970 experienced stronger trade winds. Yet the early part of the century also experienced a period of rapid global warming, despite the fact that most of the world had not industrialized, and the period 1940–70 saw a slowdown in global temperature rise despite the increase in industrial production. The researchers conclude that Pacific trade winds “significantly influence the rate of surface air temperature change.”