‘Beaches, dunes threatened by greenhouse effect’

Press, 25 January 1989, Page 30

‘Beaches, dunes threatened by greenhouse effect’

PA Wellington Beaches and sand dunes in the north of New Zealand faced significant erosion problems as the greenhouse warming brought more storms, said a Meteorological Service scientist, Dr Jim Salinger. Dr Salinger said climate records suggested the southern oscillation, which affected winds and currents in the Pacific Ocean, would stay more in its positive phase as the climate warmed — bringing more storms to the north-east of New Zealand.

“This has been borne out by records taken at the Leigh marine labora-

tory,” Dr Salinger said. “Twenty years of records of wave surges show that when the southern oscillation is very positive, you get more big seas whipped up off north-east New Zealand.”

The wave surges would bring quite significant practical problems for the north. "Bigger wave surges and wave heights will mean increased foreshore erosion and beachfront erosion,” Dr Salinger said.

The southern oscillation is still in the positive La Nina phase, and scientists are waiting to see if it follows its previous patterns and becomes less

positive around autumn this year. If it continues in the La Nina phase after autumn, scientists say this will be a good indication that climatic changes caused by the greenhouse effect had already begun. Dr Salinger said last year broke far more weather records than normal, possibly indicating that the greenhouse warming was under way. “Britain is having its mildest winter ever,” he said.

“In New Zealand, Christchurch, Blenheim and Masterton had the warmest years on record, while Auckland had its

cloudiest year, and Milford Sound broke all its records for rainfall.”

Dr Salinger said that sort of weather pattern was likely to continue as the greenhouse effect began. “It now seems possible the South Island’s east coast will become drier, with a more humid tropical climate developing in Auckland,” Dr Salinger said.

“And in fact, that is what we’ve seen in the past year. Auckland had fewer sunshine hours than Wellington, or than Dunedin airport, and so far this year that pattern is continuing.”