Pollution from north ‘disastrous’ for Ice

Press, 8 October 1987, Page 30

Pollution from north ‘disastrous’ for Ice

OLIVER RIDDELL

In Wellington

Environmental pollution from the Northern Hemisphere is having a particularly disastrous effect on Antarctica and southern lands affected by icemelt, according to a research scientist with the Meterological Office, Dr Tom Clarkson. He told the “Policies on Ice” seminar in Wellington that in the absence of a nuclear. war the two greatest environmental hazards man had created were the Greenhouse Effect and the depletion of the ozone layer. They were both global problems originating from ijas emissions, mainly in i he Northerm Hemisphere. Both had effects 'oh Antarctica that were special and serious. Both were controllable or could

have the effects delayed only by co-operative international action now, Dr Clarkson said. The Greenhouse Effect was a wanning of the atmosphere as a result of carbon dioxide, methane, nitrous oxide and chlorofluorocarbons (C.F.C.S) through human activity. The best predictions were that by 2030 global temperatures would rise by 1.5 to 4.5 deg., he said. Temperature rise was predicted to be uneven, with a rise of perhaps 8 or 10 deg. in polar regions.

This was happening now. The warming of the sea would lead to a melting of ice shelves and a consequent break-up of the west Antarctica ice sheet during the next few centuries. Dr Clarkson said this might mean a rise in the

sea level of one metre within 50 years, and of about 10 metres when the west Antarctica ice sheet melted.

There were virtually no policies and had been no planning for this, he said.

Dr P. J. Barrett of the Antarctica Research Centre at Victoria University said Antarctica had been relatively ice-free as recently as three million years ago. Recent studies suggested rapid deglaciation over hundreds rather than thousands of years for the last Northern Hemisphere glaciations.

Two conclusions could be drawn from this, Dr Barrett said. The stability of the Antarctic ice sheet could no longer. be presumed and changes in solar radiation, although they might be gradual, need not mean that

changes in climate and ice volume might not be sudden.

Dr Clarkson said progress had been made on the ozone layer problem with the recent protocol on C.F.C. production to which New Zealand was a signatory. That was not going far. enough, but was. a very significant first step forward, he said. Each spring about 50 per cent of the ozone over part of Antarctica — now? called the “Ozone Hole” — disappeared for about two months. This seasonal change could only be explained by the impact .of CF.Ca

Research activity to determine the causes and characteristics of this was now intense, he said. New Zealand was working hard to ensure protection of the ozone layer by controlling GF.Cs.