It is associated with an atmospheric pressure inversion between Tahiti and Darwin Australia which peaks at Christmas, giving El Nino the name of the Christ child. Although El Nino has been with us for centuries and previous droughts in the Amazon believed to be associated with the Southern Oscillation have been described in the archaeological record, the end of the century has been associated with an increasing series of severe El Ninos, the last of which in 1997 triggered widespread forest fire damage in the Amazon and Indonesia , disrupting ecosystems from Africa to the Galapagos. Although it is debated whether accentuated El Nino is a direct consequence of global warming, its association with warm bodies of water and increasing severity are both consistent with the predicted effects of global warming in simulations which indicate anomalous changes in global weather patterns. A second coupling between ocean and atmosphere, the North Atlantic conveyor which moves warm water up to the Arctic from the tropics is essential in moderating European weather from the severe effects of the wind flows off the Arctic ice sheets. Model predictions suggest that global warming could move the limit of the conveyor south, which would precipitate severe winters as were sometimes seen in the middle ages.
Warm waters moving west feed the Asian monsoon.
Global warming could carry the limit of the conveyor south causing freezing winters in Europe. The overall prediction for moisture and precipitation can be ascertained from the maps of the predicted global distribution of global warming and precipitation and the simulations of global warming precipitation changes . Generally these lead to a wetter more stormy world overall, but one in which precipitation moves regionally in such a way that some large productive areas with marginal rainfall including significant areas of the US could become arid while other places will becomes wetter. Some of these predictions fail to completely model the concomitant effects of the Southern and North Atlantic oscillations which may fluctuate in such a way as to drop more precipitation on areas of low rainfall such as the Atacama desert, while leaving current rainforest areas, such as the Amazon in a state of drought. Disrupting existing ecosystems and productive areas alike is likely to be of great harm both to biodiversity and to the world economy.