Global warming weakens air currents

[cal04]

The vast looping system of air currents that fuels Pacific trade winds and climate from South America to South-East Asia may be another victim of climate change, according to scientists. This could mean more El Nino-like weather patterns in the United States, more rain in the western Pacific and less nourishment for marine life along the Equator and off the South American coast.

Australia's north and east would probably be drier than normal. Known as the Walker circulation, the system of currents functions as a huge belt stretching across the tropical Pacific. Dry air moves eastward at high altitude from Asia to South America and moist air flows westward along the ocean's surface, pushing the prevailing trade winds. When the moist air gets to Asia, it triggers massive rains in Indonesia. Then it dries out, rises and starts the cycle again, heading east.

System weakens

The system has weakened by 3.5 per cent over the past 140 years and the culprit is probably human-induced climate change, scientists report in today's issue of the journal Nature. "This is the impact of humans through burning coal, burning benzene, gasoline, everything," said Dr Gabriel Vecchi of the US National Oceanic and Atmospheric Administration. "It's principally the greenhouse gases from fossil-fuel burning." The observed slowdown has been more pronounced in the past 50 years, Dr Vecchi says, noting this fits with what theorists and computer models predict should happen as a result of human-induced global warming.

Dr Vecchi says it is not consistent with any natural fluctuation in the system. Even this relatively small weakening in the Walker circulation means a much larger slowing of wind-forced ocean currents. While these potential effects are being studied, Dr Vecchi says it could mean more rain in the southern US, droughts elsewhere in North America, and more rain in Pacific islands like Kiribati.

http://www.abc.net.au/news/newsitems/200605/s1631069.htm

[XemaSab]

1. This would lead to the starvation of millions... if not billions...

This is part of the system that brings the Monsoons to Southeast Asia. Failure of the Monsoons would result in massive famine in India, among other places.

Not to mention the fact that fisheries and marine ecosystems along the west coast of North and South America would fail due to reduction in upwelling. Futhermore, several years of flooding in California would devastate the economy.

This is no trivial thing... Walker circulation controls conditions on both sides of the Pacific.

[Dead_Parrot]

2. OK, I'm scared.

Are we screwed yet?

[kitkatrose]

3. We've been screwed for a while now. n/t