Ozone Hole Linked to Climate Effects

We were extremely lucky in thatwe were able to connect the dots and phasing out CFC’s was in fact a practicaloption as an alternative was immediately available.  Had it meant the end of refrigeration wewould still be waiting.

The format still needs to be appliedto a host of problem industrial protocols and international agreements have theadvantage of fostering greater efforts. 

Yet we have also had the idiotic Kyoto accord which wasnaturally impractical and then dodged by everyone in one way or the other.

Let us go back to selected targetswere regulated replacement is the proper response.  Perhaps we can start with replacing sugarwith stevia in beverages. 

Study links ozone hole to climate change all the way to the equator

by Staff Writers

New York NY(SPX) Apr 27, 2011

Thanks to the 1989 MontrealProtocol, now signed by 196 countries, global CFC production has been phasedout. As a result, scientists have observed over the past decade that ozonedepletion has largely halted and they now expect it to fully reverse, and theozone hole to close by midcentury.

http://www.terradaily.com/reports/Study_links_ozone_hole_to_climate_change_all_the_way_to_the_equator_999.html

In a study to be published in the April 21st issue of Science magazine,researchers at Columbia University's School of Engineering and Applied Sciencereporttheir findings that the ozone hole, which is located over the South Pole, hasaffected the entire circulation of the Southern Hemisphere all the way to theequator.

While previous work has shown that the ozone hole is changing theatmospheric flow in the high latitudes, the Columbia Engineering paper, "Impact ofPolar Ozone Depletion on Subtropical Precipitation," demonstrates that theozone hole is able to influence the tropical circulation and increase rainfallat low latitudes in the Southern Hemisphere.

This is the first time that ozone depletion, an upper atmosphericphenomenon confined to the polar regions,has been linked to climate change from the Pole to the equator.

"The ozone hole is not even mentioned in the summary forpolicymakers issued with the last IPCC report," noted Lorenzo M. Polvani,Professor of Applied Mathematics and of Earth and Environmental Sciences,Senior Research Scientist at the Lamont-Doherty Earth Observatory, andco-author of the paper. "We show in this study that it has large andfar-reaching impacts. The ozone hole is a big player in the climatesystem!"

"It's really amazing that the ozone hole, located so high up inthe atmosphere over Antarctica, can have an impact all the way to the tropicsand affect rainfall there - it's just like a domino effect," said SarahKang, Postdoctoral Research Scientist in Columbia Engineering's Department ofApplied Physics and Applied Mathematics and lead author of the paper.

The ozone hole is now widely believed to have been the dominant agentof atmospheric circulation changes in the Southern Hemisphere in the last halfcentury.

This means, according to Polvani and Kang, that internationalagreements about mitigating climate change cannot be confined to dealing withcarbon alone- ozone needs to be considered, too. "This could be a realgame-changer," Polvani added.

Located in the Earth's stratosphere, just above the troposphere (whichbegins on Earth's surface),the ozone layer absorbs most of the Sun's harmful ultraviolet rays. Over thelast half-century, widespread use of manmade compounds, especially householdand commercial aerosols containing chlorofluorocarbons (CFCs), hassignificantly and rapidly broken down the ozone layer, to a point where a holein the Antarctic ozone layer was discovered in the mid 1980s.

Thanks to the 1989 MontrealProtocol, now signed by 196 countries, global CFC production has been phasedout. As a result, scientists have observed over the past decade that ozonedepletion has largely halted and they now expect it to fully reverse, and theozone hole to close by midcentury.

But, as Polvani has said, "While the ozone hole has beenconsidered as a solved problem, we're now finding it has caused a great deal ofthe climate change that's been observed." So, even though CFCs are nolonger being added to the atmosphere, and the ozone layer will recover in thecoming decades, the closing of the ozone hole will have a considerable impacton climate.

This shows that through international treaties such as the Montreal Protocol, whichhas been called the single most successful international agreement to date,human beings are able to make changes to the climate system.

Together with colleagues at the Canadian Centre for Climate Modellingand Analysis in Victoria, BC, Kang and Polvani used two differentstate-of-the-art climate models toshow the ozone hole effect. They first calculated the atmospheric changes inthe models produced by creating an ozone hole.

They then compared these changes with the ones that have been observedin the last few decades: the close agreement between the models and theobservations shows that ozone has likely been responsible for the observedchanges in Southern Hemisphere.

This important new finding was made possible by the internationalcollaboration of the Columbia University scientistswith Canadian colleagues.

Model results pertaining to rainfall are notoriously difficult tocalculate with climate models, and a single model is usually not sufficient toestablish credible results. By joining hands and comparing results from twoindependent models, the scientists obtained solid results.

Kang and Polvani plan next to study extreme precipitation events, whichare associated with major floods, mudslides, etc. "We really want toknow," said Kang, "if and how the closing of the ozone hole willaffect these."