Global warming could make it easier for non-native plants to take root on the Arctic's Svalbard archipelago, but one researcher is fighting the problem on the ground level, Der Spiegel reports. Chris Ware has set up shop at Longyearbyen’s airport, where he cleans arriving passengers' shoes. "Dirt almost always contains seeds," he said. "Sometimes it is one, sometimes it is 30 or 40."
Humans have introduced 20 plant species to the islands, which lie between the North Pole and Norway. Ware fears that number will grow as global warming makes it easier for plants to adapt. "Once the new species are here, there is practically nothing that can be done about it." But as Ware assesses the threat, another looms: animals arriving by sea.