Matt Simon

The Arctic island of Svalbard is so reliably frigid that humanity bet its future on the place. Since 2008, the Svalbard Global Seed Vault — set deep in frozen soil known as permafrost — has accepted nearly 1.4 million samples of more than 6,000 species of critical crops. But, the island is warming six to seven times faster than the rest of the planet, making even winters freakishly hot, at least by Arctic standards. Indeed, in 2017, an access tunnel to the vault flooded as permafrost melted, though the seeds weren’t impacted. This February, a team of scientists was working on Svalbard when irony took hold. Drilling into the soil, they gathered samples of bacteria that proliferate when the ground thaws. These microbes munch on organic matter and burp methane, an extremely potent greenhouse gas and significant driver of global warming. Those emissions are potentially fueling a feedback loop in the Arctic: As more soil thaws, more methane is released, leading to more thawing and more methane, and on and on.  Read Next Ice roads are a lifeline for First Nations. As Canada warms, they’re disappearing. Hilary Beaumont In some parts of Svalbard, though, the scientists didn’t need to drill. Air temperatures climbed above freezing for 14 of the 28 days of February, reaching 40 degrees Fahrenheit, when the average temperature at this time of year is 5 degrees. Snow vanished in places, leaving huge pools of water. “I brought my equipment to drill into frozen soil and then ended up sampling a lot of soil just with a spoon, like it was soft ice cream,” said Donato Giovannelli, a geomicrobiologist at the University of Naples Federico II and co-lead author

Like so much of an iceberg is hidden underwater, much of a tree is hidden underground. While the trunk and branches and leaves sequester planet-warming carbon dioxide, trees and other plants have long formed subterranean alliances with mycorrhizal fungi, which intertwine with their roots to establish a mutually beneficial trade network. In exchange for helping everything from oaks to redwoods find water and essential nutrients like nitrogen, the fungi get energy, in the form of carbon that their partners have pulled from the atmosphere.  A whole lot of carbon, in fact: Worldwide, some 13 billion tons of CO2 flows from plants to mycorrhizal fungi every year — about a third of humanity’s emissions from fossil fuels — not to mention the CO2 they help trees capture by growing big and strong. Yet when you hear about campaigns to conserve and plant more trees to slow climate change, you don’t hear about the mycorrhizal fungi. Humanity may be missing the forest for the trees, in other words, in part because without going somewhere and digging, it’s hard to tell what mycorrhizal species are associating with what plants in a given ecosystem. Mycorrhizal fungi in Italy’s Apennine Mountains Seth Carnill A new research project is trying to change that. The Society for the Protection of Underground Networks, or SPUN, has launched the Underground Atlas, an interactive tool that maps mycorrhizal fungi diversity around the world. It’s a resource for scientists and conservationists to better understand where to focus on protecting these species so they can keep sequestering carbon and provide other critical services in ecosystems. “We’ve known for a long time that these mycorrhizal fungi are very important in ecosystems, and that they exist all over the planet and partner with lots of different plants,” said fungal ecologist Michael Van Nuland, lead

From Texas clear to Georgia, from the Gulf Coast on up to the Canadian border, a mass of dangerous heat has started spreading like an atmospheric plague. In the days and perhaps even weeks ahead, a high-pressure system, known as a heat dome, will drive temperatures over 100 degrees Fahrenheit in some places, impacting some 160 million Americans. Extra-high humidity will make that weather even more perilous — while the thermometer may read 100, it might actually feel more like 110.  So what exactly is a heat dome, and why does it last so long? And what gives with all the extra moisture?  A heat dome is a self-reinforcing machine of misery. It’s a system of high-pressure air, which sinks from a few thousand feet up and compresses as it gets closer to the ground. When molecules in the air have less space, they bump into each other and heat up. “I think about it like a mosh pit,” said Shel Winkley, the weather and climate engagement specialist at the research group Climate Central. “Everybody’s moving around and bumping into each other, and it gets hotter.” But these soaring temperatures aren’t happening on their own with this heat dome. The high pressure also discourages the formation of clouds, which typically need rising air. “There’s going to be very little in the way of cloudiness, so it’ll be a lot of sunshine which, in turn, will warm the atmosphere even more,” said AccuWeather senior meteorologist Tom Kines. “You’re just kind of trapping that hot air over one part of the country.” In the beginning, a heat dome evaporates moisture in the soil, which provides a bit of cooling. But then, the evaporation will significantly raise humidity. (A major contributor during this month’s heat dome will be the swaths of corn crops