Last year’s summer was also record hot. Everything indicates that two records on the rap are not random results, but linked to climate change, says Professor Rolf Anker Ims. The researchers have now made an analysis of the summer’s measurements: – The temperatures we observed on Svalbard in August would only be experienced one in 10 million times if the climate were normal, says Ims. In Eastern Finnmark, it has been 3–4 degrees warmer than normal on barren mountain tops, far above the forest line. The chance that this record is just a fluke is 1 in 500. The researchers then compare it with the normal for the period from 1990 to 2020. Two record summers in a row is of course even less likely, says Professor Ims. He leads the climate research in the Coat project, which has an extensive array of weather stations on Svalbard and on the Varanger Peninsula in Finnmark. Coat has been removed from the government’s proposal for the national budget and has an uncertain future. The weather stations on the Varanger Peninsula, such as this one at the Ragnarok cabin, have this summer measured temperatures 3–4 degrees above normal. Photo: Jan Erik Knutsen, Coat Warm enough for forests Such high temperatures can lead to dramatic changes in nature in the longer term. – Now summers are so hot and summers so long that there are growing conditions for trees in certain places on Svalbard and almost everywhere in Eastern Finnmark, says the professor. You can read details about the growing season in the fact box. This affects the growing season in the mountains and in the Arctic Traditionally, researchers have used the average temperature in July as a criterion. The limit for arctic climate – and thus the tree limit – is set at 10 degrees. But there are more precise criteria. – What describes both arctic and alpine tree lines best is a combination of how hot it is on average in the growing season, especially July and August, and how long the growing season is, says Rolf Anker Ims. The growing season must consist of at least 94 snow-free days with daily temperatures above 0.9 degrees. The average temperature over this season must be at least 6.4 degrees. If these criteria are met over many years, then the climate is suitable for trees to grow. In both 2023 and 2024, the criteria were met at all Coats weather stations on the Varanger Peninsula, as well as some of the weather stations on Svalbard. In principle, migratory birds such as this snow sparrow can bring seeds from birch across the sea to Svalbard, but it is uncertain how quickly this can happen in practice. Photo: Knut-Sverre Horn But even if it is technically possible with a forest, it may still happen that the trees come rather slowly. Investigations of pollen profiles in bogs have provided data from past climate changes. Then it has taken several hundred years before you have a full-fledged forest, according to Ims. Smaller plants such as crickets can also respond much faster than trees. At the same time, there can be outbreaks of pests that reproduce extremely quickly. Many places on the Nordkalotten have experienced huge outbreaks of butterflies in the meter family. The larvae are called leaf maggots and scavenge the forest. – It is the type of surprises that we expect more of. But these things that happen quickly, they can turn the ecosystem completely upside down. Rolf Anker Ims on field work at one of the weather stations in Varanger in winter. Photo: Knut-Sverre Horn / news The high temperatures can affect the vegetation in a short time if they come together with drought. – But then it is often the case that part of the natural vegetation can be quite resistant, says Ims. Disturbingly dry Reindeer owner Jan Ivvár Smuk has her herd on summer pasture on the Varanger Peninsula. – It was almost a bit precarious at the end of the summer. It was dry everywhere, he says. – I went for a walk above Vadsø, and saw that a number of smaller lakes had dried up. He noticed that on the reindeer herd: – At the end of August, it didn’t look so good. It wasn’t a crisis, but there was no point in slaughtering then. As soon as it rained in mid-September, both plant growth and the weight of the reindeer picked up. It was a month postponed. Reindeer owner Jan-Ivvár Smuk has rarely worried about drought. Now there may be new times in Eastern Finnmark. Photo: Knut-Sverre Horn / news Smuk and his colleagues slaughtered the reindeer later than planned, partly because of the drought. He is worried about what might happen if this summer weather becomes the new normal. – You almost have to take a dark look at it. I think you have to start using the pastures differently and perhaps have a contingency plan. But I don’t know what to do, drill a well in the middle of the Varanger Peninsula? – Drought is a bigger concern than I would have imagined. It has not been a problem in the past, says Smuk. news has written several cases about how climate change affects nature and wildlife in Finnmark: Published 15.11.2024, at 11.14
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Warm enough for forests on Svalbard and on the tundra in Finnmark – news Troms and Finnmark
