The Sami, the only indigenous people left in Europe, have more than 100 different words for snow. From seaŋáš, a fluffy, grainy snow that moves easily, to tjaevi, flakes that stick together and are hard to dig, the names are based on its texture, depth, density, and the harsh conditions of the Arctic winter. But the Sami of Sápmi, who are traditionally fishers, trappers and reindeer herders, do not yet have a word for what they are seeing more often on the ground. “This new snow has no name,” said Lars-Anders Kuhmunen, a reindeer herder from Kiruna, Sweden’s northernmost town, near the Norwegian border. “I don’t know what it is. It is like early tjaevi, which normally comes in March. The winters are warmer now and there is rain, making the ground icy. The snow on top is very bad snow and the reindeer can’t dig for their food.” The Arctic is warming not twice as quickly as the rest of the world, as previously believed, but four times as fast, according to a paper published in Science this week. Sápmi, an area that stretches over parts of four countries – Sweden, Finland, Norway and Russia – and is hemmed by three seas, recorded its hottest temperature for more than a century in July this year, hitting 33.6C (92.5F) during a summer heatwave. Kuhmunen and other reindeer herders, who spend their days and often nights tending the herds scattered across vast tundras, are on the frontline of the climate crisis. Their reindeer, a semi-domestic species that has adapted to the harsh conditions of the polar region, are being pushed to the limit by the changes, they say. The animals use their shovel-like hooves to dig for lichen, their main winter food supply, as well as other plants that grow under the snow. But finding food is increasingly difficult. Warmer than average temperatures mean the snow that was semi-permanent throughout winter turns to rain, which in turn freezes on the ground, trapping lichen under the ice, so the animals cannot reach it. Thick snowfall, which also happens more often, adds to the problems by making it impossible for the animals to find the lichen by smell. These freeze-thaw and rain-on-snow events happen naturally in the Arctic, but they are happening more often and on a larger scale. There have been mass starvations of reindeer, in 2013-14 in Russia and in 2018-19 in Norway, and the herders have to go much farther afield in the past few years to find grazing ground. Kuhmunen, 43, a father of three, said the changing weather and shrinking grazing lands had made his job much harder. Speaking from the forest, six miles (10km) north of Kiruna, where he is following his herd, he said: “It’s hard to keep the herd together, so I have to work harder. They spread out more because they can’t find food. Now there are only four or five hours of daylight. When the polar darkness comes it will be harder.” He adds: “Reindeer are losing their habitat, because of logging and mines. My father’s generation used to go on skis to the reindeer. We use snowmobiles because the distances are greater. I worry about it every day.” The herding of reindeer is already threatened by human expansion, with forestry and mining activities moving into traditional grazing grounds. One study in Norway found that in the last century, undisturbed reindeer habitat had shrunk by 70%, including grazing lands flooded for hydroelectric dams. The climate challenges faced by the Sami – and the impact on their rights and livelihood – have been researched and documented by the Environmental Justice Foundation (EJF), one of four charities in the Guardian and Observer’s 2021 climate justice appeal, as part of an international effort to lobby politicians to take climate action.