Monday 6 August 2018
Much of the extreme heat in the world this summer is linked to abnormal winds in the atomic sphere – and to man-made global warming.
In Norway, the exceptionally hot summer came almost immediately after the even more abnormal month of May, when the national warmth rule was regularly broken.
The situation in Norway, Sweden and Finland has been one of many extreme weather events in the northern hemisphere. Canada, USA, Northern Europe, parts of the Middle East, Caucasus and Japan have experienced extreme hot or drought.
Many climate researchers believe there can hardly be any doubt that man-made global warming has made the wave of heat waves worse than it would otherwise be.
“Serious climate change is taking place in front of our eyes,” Professor Rowan Sutton told The Guardian.
– No doubt
Bjørn Hallvard Samson at the research center CICERO uses somewhat less dramatic words, but agrees in essence.
“Global warming has made this worse, there is no doubt about it,” he told NTB.
The average temperature of the globe has moved upwards, as emissions of greenhouse gases from coal, oil, transport, industry, deforestation and agriculture. Therefore, when heat waves occur, they will typically be somewhat warmer than before.
Still new heat cores are completely in line with what we can expect. Over the last few months, new records have been set in more than 15 different countries.
– This is not a future scenario. It’s happening now, she emphasizes.
Gradual warming of the globe is nevertheless the only trend that affects the heat waves.
The weather will always be influenced by a multitude of coincidences. And climate change can also take place in more indirect ways.
One example is that climate change in many places leads to more severe droughts. If the drought comes with a heat wave, the dried soil can enhance the heat.
In addition, global warming may affect the polar front and a belt of strong winds high up in the nuclear sphere. The belt, a so-called jet stream, stretches around the northern hemisphere, across the polar front.
Jet flow is of great importance to the weather in Norway and other countries on our latitudes. Some scientists believe the wind system now behaves differently than before – and that high pressure therefore more often remains in peace.
– A key player
Unusual movements in the jet stream are drawn as an explanation of stable high pressure and extreme heat both in Scandinavia, Canada, USA and Japan this summer.
“Jetstream has been a key player in the sensational heat wave across Britain and Scandinavia,” said American researcher Jennifer Francis to the New Scientist magazine.
The connection between the jet stream and climate change is nevertheless uncertain. The theory is faced by, among others, Francis, while other researchers are skeptical.
While researchers continue to understand the consequences of climate change, the consequences of summer’s heat waves have been very concrete and in some cases tragic.
In Japan, more than a hundred people died shortly after more than two hundred died in flooding. Around 70 died in Canada’s heat. The Greek authorities believe climate change contributed to the fires near Athens, where over 90 perished.
Many Norwegians have instead looked forward to delicious summer weather – but not the peasants who have seen crops fade away on the fields.