Friday, October 12, 2007

Three headed dog

We knew that changing climate back was long term. But 600 years ? At least that is what the a phenomenon called by CSIRO climate scientist Dr Wenju Cai (marine and atmospheric research) calls the "three headed dog." Avid Planet Ark-ers will have read this already to much of their dismay I am sure.

But even if we fix climate and arrest global greenhouse gas emissions (he mentions CO2 but one may also count in methane) the recovery will take longer than our lifetime, much longer. Over half a millennium, according to Cai and his calculations.

What it means that in southeast and southwest Australia their is an unsavory combination of climate elements causing extended drought. The Indian Ocean Dipole, the Southern Annular Mode shifting westerlies southward, and increasingly powerful El Nino events create three interacting prongs.

1. Confluence of a "wet weather" La Nina event in the Pacific and a "dry weather" Indian Ocean Dipole effect in the west, where the dry Indian Ocean weather effect is overwhelming the wet La Nina event. As a result, El Ninos become more frequent and possibly more powerful.

2. Rising temperatures warm the dry Australian landmass faster than the ocean [partly due to much of it's barren surface]. In southwest Western Australia, the drying-out is being intensified by westerly wind jets shifting towards the Antarctic in response to ozone depletion over the last 30 years.

3. Unabated and increasing carbon dioxide emissions. This third prong also intensifies the other two.

Putting it in perspective: If farming will relocate to wetter areas (where-ever they may form) for the next 600 years, would you call that adaptation to climate or an utter change of nomadic proportions?

The questions now on everyone's lips: is that INEVITABLE?

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