\u201cThink of it like a freezer,\u201d Moon said. \u201cWhile that chicken\u2019s in your freezer, it\u2019s good to go for years, no worries. And as soon as you take it out, it\u2019s thawing, all the microbes are getting to work.\u201d<\/p>\n
Warming temperatures thaw the permafrost and stir the microbial communities. As the permafrost thaws, the carbon that is stored gets released. This leads to one of the most significant findings of the new report: the Arctic tundra has transitioned from a carbon sink to a net emitter of CO2.<\/p>\n
Add to that an increase in wildfires, and the region is now releasing more CO2 than it stores. In 2024 alone, wildfires north of the Arctic Circle released 42.3 million metric tons of CO2, making it the second-highest fire emissions year on record for the high Arctic.<\/p>\n \u201cThis landscape has been storing carbon for us for thousands of years, throughout the Industrial Revolution,\u201d Moon said. \u201c[The Arctic] has done a lot of work of taking carbon up for us, instead of leaving it in the atmosphere \u2026 This is one of those places where we\u2019re seeing the landscape no longer able to do that work.\u201d<\/p>\n Another place is the Brazilian Amazon, declared a net carbon source in 2021, primarily due to emissions from fires.<\/p>\n The temperature has also been rising. The past nine years have been the warmest on record in the Arctic, with 2024 marking the second-warmest year since 1900. An early August heat wave in 2024 set an all-time record for daily temperatures across northern Alaska and Canada.<\/p>\n The implications of this change extend far beyond the Arctic. \u201cAs we\u2019re heating up the Arctic, we\u2019re changing the way that our air flows around the planet, and we\u2019re actually making it easier for these blasts of Arctic air to come south,\u201d Moon said. She suggested thinking about it \u201cnot as global warming, but as global weirding, which is why you can have a cold event that is really unprecedented and surprising.\u201d<\/p>\n While the Arctic region heats up, its role as Earth\u2019s cooling system weakens. Large expanses of white sea ice covering the Arctic Ocean \u201chelped to reflect energy and heat back out to space and act as a cooler system for our planet,\u201d Moon said. But as the ice melts, the surface darkens and absorbs rather than reflects heat.<\/p>\n September 2024 marked the sixth-lowest sea ice extent in the 45-year satellite record. The remaining ice is also younger and thinner, with old, thicker ice reduced by 95% since the 1980s.<\/p>\n The region\u2019s wildlife also faces challenges. Populations of migratory tundra caribou (Rangifer tarandus) have declined by 65% over the past two to three decades. Though some smaller coastal herds in the western Arctic show signs of recovery, the largest inland herds continue declining or remain at historic lows. Scientists project that summer heat will intensify over the next 25-75 years, which could further affect the caribou.<\/p>\n Tundra greenness, measuring expanding vegetation cover and biomass, reached its second-highest level in the 25-year satellite record. \u201cGreening isn\u2019t as positive as it sounds,\u201d Moon said. \u201cFor the caribou, these shrubbier plants are crowding out the lichen that are their food source, and so it\u2019s becoming harder for them to get to their food source.\u201d<\/p>\n While Pacific Arctic ice seals \u2014 ringed (Pusa hispida), bearded (Erignathus barbatus), spotted (Phoca largha) and ribbon seals (Histriophoca fasciata) \u2014 remain healthy overall, their diets are shifting. Ringed seals, for example, are eating more saffron cod (Eleginus gracilis) and less Arctic cod (Arctogadus glacialis) as the waters warm. Scientists aren\u2019t yet sure how this diet change will affect the population.<\/p>\n To understand how the Arctic\u2019s carbon storage is changing, scientists use two main tools: ground stations and satellites. Ground stations across the Arctic directly measure gases moving between the land and air, like taking the region\u2019s temperature. Meanwhile, satellites watch for changes from above, tracking wildfires, melting ice, and growing plants. The team used 30 years of CO\u2082 data (1990-2020) from 200 monitoring sites.<\/p>\n \u201cThe high resolution of these data means that we can now see how variable the Arctic is when it comes to carbon,\u201d Sue Natali, lead of the Permafrost Pathways initiative at the Woodwell Climate Research Center in the U.S. and a co-author of the study, said in an interview. \u201cThe Arctic isn\u2019t one single place \u2014 it\u2019s a massive area with diverse ecosystems and climatic conditions. And now we have the capability to track and map carbon processes at a spatial resolution that can reveal what\u2019s happening on the ground.\u201d<\/p>\n The Arctic is also home to about 4 million people, including around half a million Indigenous people. This year\u2019s report touches upon Indigenous knowledge through the work of the Ittaq Heritage and Research Centre in Kangiqtugaapik (Clyde River), Nunavut, Canada.<\/p>\n \u201cInuit hunters are the original researchers of their homelands,\u201d write Sherry Fox and Mike Jaypoody in their report essay. \u201cObservation, monitoring, and research skills are all integral parts of being a hunter or harvester.\u201d<\/p>\n Their essay highlights how the center\u2019s Angunasuktiit program teaches new generations traditional hunting and harvesting skills, combining Indigenous knowledge with modern technologies like custom-programmed satellite communication devices, digital photos, video, and drones.<\/p>\n \u201cKnowledge is a practice. It cannot be separated from the people, culture, language, and land, and it cannot always be adequately expressed in western scientific terms,\u201d write Fox and Jaypoody.<\/p>\n Moon said that collaboration between scientific and Indigenous communities is essential for addressing challenges. \u201cBeing able to collaborate across places about how folks are preparing for disasters, preparing for extreme weather, how they\u2019re then responding to it, there\u2019s a lot of opportunity for collaboration and learning from each other,\u201d she said, adding that such coordination \u201cis going to make us more resilient and help us to reduce risks.\u201d<\/p>\n The report concludes that supporting Indigenous leadership and ways of life, alongside sustained climate action will be crucial for understanding and responding to rapid Arctic change.<\/p>\n While the findings are sobering, action remains vital, Moon said. \u201cThere\u2019s not ever an expiration point in us doing our best to show up in an optimal way or create minimized risk or better preparedness into the future.<\/p>\n \u201cThis is really a new and different Arctic,\u201d she added. \u201cIt\u2019s not a new normal. We haven\u2019t arrived at an end point or something that will stabilize. It\u2019s still continuing to change rapidly \u2026 We ignore the Arctic to our peril at this at this point.\u201d<\/p>\n Moon, T. A., Druckenmiller, M. L., & Thoman, R. L. (2024). NOAA Arctic Report Card 2024. doi: 10.25923\/b7c7-6431<\/p>\nCitation:<\/h2>\n