Since 1935, the Norilsk metallurgical complex in Siberia has been releasing large amounts of nickel into the atmosphere without pollution controls, with emissions reaching as far as 300 kilometers beyond the Arctic Circle. This industrial hub, located approximately 300 kilometers north of the Arctic Circle, is regarded as the largest single source of pollution in the Arctic. Over the decades, its emissions have caused the death of all trees in some areas and have destroyed 24,000 square kilometers of boreal forest—roughly twice the size of the Île-de-France region in France. This destruction is now visible from space, highlighting the massive environmental impact of the factory’s operations. The Norilsk complex is responsible for emitting between 1.8 and 2 million tons of sulfur dioxide annually, which constitutes more than half of Russia’s total sulfur dioxide emissions. Sulfur dioxide is a harmful gas that damages plant life by forcing the stomata—tiny pores on leaves—to open excessively, leading to water loss and eventual death of the tree. Unlike some pollutants, sulfur dioxide does not need direct contact with plant roots to cause damage; it can travel for several days on the wind, affecting plants tens of kilometers away from the source. No other human-made facility on Earth produces such high levels of sulfur dioxide pollution, according to satellite data analyzed by scientists. Only the Ambrym volcano in Vanuatu emitted more sulfur dioxide through natural processes between 2005 and 2017. The history of the Norilsk complex dates back to the Stalinist era, when the city was built largely by prisoners from the gulag system. Today, Norilsk is home to nearly 170,000 people and remains one of the largest urban areas in the Arctic. The environmental degradation has been a long and steady process. Starting in the 1960s, the rate of forest decline accelerated as new copper and nickel deposits—rich in sulfur—were exploited, fueling the local industry. By the early 1980s, all the larch trees within a 65-kilometer radius around Norilsk had died. Despite this destruction, the city continues to produce nearly a fifth of the world’s high-quality nickel. In 2020, Nornickel, the company that operates the Norilsk complex, launched an ambitious program to reduce sulfur dioxide emissions by 95 percent by 2030. The process involves capturing sulfur dioxide and converting it into sulfuric acid, which is then neutralized with lime to produce gypsum. This method has shown promising results, with one facility achieving a 99 percent capture rate. Russian authorities have confirmed that progress is being made, with over 221,000 tons of sulfur dioxide already captured as part of a plan to reduce emissions by 45 percent by 2025. However, the project has faced delays and increased costs, partly due to Western sanctions that forced the company to find new suppliers for the final stages of the project.