Global heatwave of 1998 affects New Zealand

Climate statistics disclose that the global heatwave of 1998 is also affecting New Zealand.

15 June 1998

The latest data shows that New Zealand is in line with a new world climate analysis to be announced shortly at the White House. The U.S. analysis is expected to reveal that global average temperature for 1998 to date was an unprecedented 0.6 degrees Celsius above average. Data from the National Institute of Water and Atmospheric Research (NIWA) shows that New Zealand's heatwave over the same period was actually slightly higher at 1.2 degrees Celsius above average. Both sets of figures were matched against benchmark figures for the period 1961 to 1990.

NIWA climatologist Jim Salinger said today that the New Zealand average temperature for the five month period was 16.0 degrees Celsius compared with a 1961-1990 average of 14.8 degrees Celsius. World figures show that the average global temperature for the period was 17.1 degrees Celsius.

Dr Salinger said the New Zealand temperatures had been the highest for 60 years, and the second warmest since records began 145 years ago. The record was boosted by the exceptional temperatures in February, when New Zealand was 2.5 degrees Celsius warmer than average. Already, during June (a winter month) there have been the odd days with temperatures that have been six to seven degrees above normal.

The New York Times has quoted Thomas Karl, a senior scientist at the US National Climatic Data Centre, as saying the world temperature jump in 1998 was "rather spectacular".

United States Vice-President Al Gore, who is scheduled to present a world climate analysis at a White House briefing Monday morning US time, told the newspaper that new global temperature records were set in every month since January.

"It appears that this general warming is making the effects of El Nino worse. This is a reminder once again that global warming is real and that unless we act we can expect more extreme weather in the years ahead."

Part of the global warming has been due to the El Nino, said Dr Salinger, owing to the warmer tropical oceans. "But in New Zealand, the El Nino usually brings cooler conditions, owing to more southwesterly winds. This makes the warming for New Zealand during 1998 even more exceptional".

Dr Salinger said El Nino had been the cause of the droughts affecting eastern areas of New Zealand over the last year, while giving heavy rains in western parts of the country. "Hawke's Bay has had only one third of its average autumn rainfall", he said.

Global data on the oceans and atmosphere show the El Nino is on its way out now. NIWA scientists say that we can expect the warmer trend to continue through at least the winter period. This is mainly because of hot "patches" in the Indian Ocean and much warmer than normal seas around the north of the country. So 1998 is likely to end up being a very warm year, both in New Zealand and worldwide.

The Intergovernmental Panel on Climate Change (IPCC) has reported to the United Nations General Assembly that the Earth's average surface temperature will rise between one and three degrees Celsius by the end of the next century. This, the IPCC says, will disrupt the earth's climate, increasing precipitation. making droughts more severe and causing the sea level to rise.