Global temperature heads for new record
British and American scientists agree that the first half of 1998 was the warmest world-wide since the mid-19th century.
|
|
Global surface air temperature, January 1990-June 1998, monthly values as departures from the 1961-90 mean. The June 1998 value is provisional. The cooling in 1992 shows the effect of the volcano Pinatubo. |
Analyses by the UK Met. Office, the University of East Anglia, the National Oceanic and Atmospheric Administration and the Goddard Institute of Space Studies show that early 1998 was a remarkable period. The British data show every month to June the warmest on record. The average for the period January-June 1998 was close to 0.6 degrees Celsius warmer than the 1960-90 mean. The warmth was most marked over the tropics and parts of the Eurasian and North American landmasses.
The cause of the warmth was El Niño coupled with the underlying warming trend of recent decades. There is general agreement that part of this warming trend is the result of human interference but the precise scale of this contribution remains elusive.
With a La Niña imminent, temperatures may drop over the remaining months of 1998, but it still remains likely that 1998 will replace 1997 as the warmest year on record. “The margin depends on the rate at which the warm El Niño is replaced with cool sea temperatures in the same region,” said Phil Jones of the Climatic Research Unit at the University of East Anglia.
On the Web
Global Temperatures by Phil Jones