Heat records have not only been reached in 2018, they have been broken.This is very unlikely if the climate had not changed,researchers say.
The weather has finally normalised, after a hot spring and high summer, which overall surpassed everything living people had previously experienced in Norway.
Also, many other places in the northern hemisphere have hit temperature records.Canada, USA, Northern Europe, parts of the Middle East, Caucasus and Japan have experienced extreme heat or drought.
But of all these extremes, the long-lasting heat and drought in Scandinavia is one of the most persistent.
The average temperature in Norway from May to July was 3.1 degrees above the norm the Meteorological Institute reported to NTB news.
Something similar has never been observed before this period.The previous records were from 2002 and 1937, when it was 1.9 and 1.8 degrees warmer than normal.
If the climate is stable, gradually fewer and fewer records will be set .The meteorologists observed that it would normally be increasingly unlikely that new observations will emerge that surpass the old ones.
But such is not the situation in the world today.New heat sequences are seen often, and this year, several records have been broken.
“The temperature in May was perhaps the most sensational,” said climate scientist Rasmus Benestad at the Meteorological Institute.
The average temperature in Norway in May was 1.7 degrees above the previous record from 2013.
In Eastern Norway, the temperature was 2.7 degrees higher than the old record set in the legendary 1947 dry year.
“It’s usual when the record is broken that they beat some trends,” said Benestad’s colleague,Jostein Mamen to NTB news.
Tropical in Sigdal
Despite the extreme temperatures, the national maximum record has not been broken. It was set in Nesbyen in 1970 when it was 35.6 degrees.
However, another indication of the trend over time is the number of tropical days. These are days where the temperature passes 30 degrees.
So far this year, there have been 26 tropical days in Sigdal in Buskerud, a record among the weather stations that provide measurements.
Previously, measurements of more than 18 tropical days had never been made anywhere in Norway in the course of a single year.
The weather station in Sigdal is quite new and it is possible that it is located in a place where special conditions make it especially hot. But Blindern in Oslo has measurements back to 1931.
So far this year there have been 13 tropical days at Blindern.The previous record was nine days of tropical heat in 1955.
1 in 18,000 years
The background for the ever-changing heat records is,according to researchers, man-made global warming.
Benestad says the year’s heat increases would be very unlikely in a stable climate. He calculated that the May temperature of the year would have occurred once every
18,000 years if the climate had remained as stable as it was in the late 1800s.
But the temperature this year is very unlikely even if you take gradual warming into the calculation. Benestad believes one of the explanations of the records is that climate change alsoaffects the temperature in more indirect ways.
The changes lead to more droughts in many places, and dried soil can help raise the temperatures during a heat wave.
Some researchers also believe that climate change is causing high pressure to stay longer than it would otherwise. Long-term high pressure, as we have had in southern Norway this year, can both cause drought and long hot periods.
© NTB scanpix / #Norway Today