The Heat Is Online

Atmospheric Warming and the Changes in El Nino Patterns

The El Nino/Southern Oscillation is fundamentally a process that redistributes heat within the climate system. Tampering with the global thermostat – by injecting more greenhouse gases into the air – will likely interfere. Some possible explanations for the changed behavior of El Niños in the past twenty years are that the Warm Pool in the tropical western Pacific is expanding; and/or the recharge phase of El Niño has speeded up; and/or the heat loss phase is less efficient. Any of these could follow from warming and result in more frequent El Niño events. With global greenhouse warming we should expect higher temperatures in the upper layers of the ocean, and a steeper drop in temperature beneath the surface, which would increase the magnitude of swings between La Niña and El Niño. (From the journal CONSEQUENCES, by Dr. Kevin Trenberth.)