Antarctic ice threatened by ozone-hole recovery


Nature – April 29, 2008

Once again, we see an example of how the climate models that are predicting the end of the world, as we know it, have not taken into account some important factors.  Granted, this particular article is discussing another model (or at least calculation and prediction). It still points out that our models are far from complete and we need to spend more money and effort to increase this capability.

Recovery of the ozone hole above Antarctica could warm the Antarctic and cause more ice to melt in coming decades, researchers say. As the ozone hole heals, wind patterns that shield the interior of the polar region from warm air may break down, causing warming in the Antarctica as well as warmer and drier conditions in Australia.

“The warming of the Antarctic may have been delayed because of the ozone hole,” says atmospheric scientist Judith Perlwitz, a climate scientist at the of the University of Colorado at Boulder and the National Oceanic and Atmospheric Administration.

Perlwitz and her colleagues simulated the interaction between stratospheric ozone dynamics and atmospheric conditions between 1950 and the end of the twenty-first century. They conclude that as ozone levels recover, the lower part of the stratosphere above Antarctica — some 10-20 kilometres above Earth’s surface — will absorb more ultraviolet radiation, and rise in temperatures by as much as 9ºC, reducing the existing strong north-south temperature gradient.

Climate models, including those used in the Intergovernmental Panel on Climate Change’s (IPCC) fourth assessment, have not accounted for these details of ozone chemistry. Most models do not extend beyond 30 kilometres above the Earth’s surface, and adequate representation of the stratosphere would require modelling up to 60 kilometres. “This paper opens the discussion about how ozone depletion and recovery in the twentieth and twenty-first centuries can be included in climate models,” Perlwitz says.

“If we get the feedbacks and the ice-melt wrong in our climate models, then that means we could be really wrong in terms of what a safe level of carbon dioxode is,” says Theodore Shepherd, an atmospheric scientist at the University of Toronto, Canada, who was not involved in the study.

You can read the full article here.

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