Ozone hole closing but a slow process
September 5, 2013
The ozone hole is closing but it is a slow process and predictions are for it to recover between 2050 and 2100, a University of Canterbury (UC) expert says.
Dr Adrian McDonald says climate change in Antarctica really matters to New Zealand because it will cause ice to melt resulting in sea levels to rise.
``But, also the temperature difference between the poles and the equator controls wind patterns over NZ which could potentially mean increased-rainfall on the West Coast or dryer Canterbury Plains.
``The recent National science challenge aims to identify how climate is changing over Antarctica so that we can understand what our future might be in New Zealand.’’
Dr McDonald is giving a public lecture on the Antarctic’s global warming impact at UC next week (September 11). See an interview with him here: http://youtu.be/8eoOBL2MSjA
The Montreal Protocol, which effectively band cchlorofluorocarbons (CFCs), has helped reduce the size of the ozone hole.
The Protocol on substances that deplete the ozone layer is an international treaty which is phasing out the numerous substances believed to be responsible for ozone depletion. The treaty entered into force in 1989.
It is believed that if the international agreement is adhered to, the ozone layer is expected to recover by 2050. Due to its widespread adoption and implementation, the Montreal Protocol has been hailed as an example of exceptional international co-operation.
Ironically, stratospheric ozone depletion may have indirectly protected Antarctica from the worst of greenhouse gas-related warming.
``With the ozone recovery, the future of Antarctic climate is less certain, though the complex interactions in the atmosphere associated with climate change makes this region particularly hard to predict.
``The future recovery of the Antarctic ozone hole and increases in greenhouse gases will have significant impacts on the circulation in the southern hemisphere.
``'The increasing ozone hole has until now acted to change the circulation of the Southern Hemisphere so that the strong winds linked to the jet streams have moved towards the pole.’’
Dr McDonald said ozone recovery should act to move the winds back towards the equator, but this may be counteracted by greenhouse gas forcings. The jet-stream positions are one of the main things that help control the width of tropical and polar weather belts.
He plans to head to Scott Base in November to deploy a set of wirelessly connected weather stations to obtain high resolution weather data as part of his Antarctic research.