Frequent wildfires have transformed the Arctic tundra from being a carbon sink to an active carbon source, as the Arctic continues to warm for 11 consecutive years.
The 2024 Arctic Report Card released by National Oceanic and Atmospheric Administration (NOAA) noted that after storing carbon dioxide in the frozen soil for thousands of years, now record-breaking and near-record-breaking observations highlight dramatic changes in the region.
The Arctic region is a major carbon sink absorbing high levels of carbon dioxide from fossil fuel emissions.
Climatic shifts are forcing plants, wildlife and the people that depend on them to rapidly adapt to a warmer, wetter and less certain world, the report noted.
The annual report shared updates on eight vital signs including - ocean primary productivity and surface temperatures to tundra greenness and snow cover. It also examined three indicator topics consisting of Alaska ice seals, North American caribou and Arctic lands as sources of global heat-trapping carbon emissions.
But the report suggests these multidecadal records for many of these signs indicate that the Arctic now exists within a ‘new regime’.
The new regime is suggested on the basis of not setting the new records alone, but these observations being consistent with extreme ranges compared to previous baseline records.
For example, though the minimum sea ice extent for 2024 was only the sixth lowest on record (beginning in 1979), the last 18 September extents are the 18 lowest within those 45 years, the report said.
Similarly, the extent of thicker and older ice, a crucial habitat for many species, continues to remain low since 2007.
“Our observations now show that the Arctic tundra, which is experiencing warming and increased wildfire, is now emitting more carbon than it stores, which will worsen climate change impacts,” said NOAA Administrator Rick Spinrad, in a statement issued by NOAA.
“This is yet one more sign, predicted by scientists, of the consequences of inadequately reducing fossil fuel pollution,” he added.
The report was prepared collectively by 97 scientists from 11 countries to reveal the observations from the Arctic which includes dramatic changes in land, sea and air.
The scientists highlighted the high air temperatures and wildfires and decline in large populations of caribou herds owing to unsuitable habitat.
The report also noted the increasing precipitation, including rain-on-snow events that cover the landscape in an icy shell, making it challenging for people and wildlife to travel and forage.
Among the notable findings, the scientists observed that arctic annual surface temperatures were the second warmest in 125 years since 1900. In autumn 2023 and summer 2024 the temperatures ranked second and third warmest respectively.
The summer of 2024 across the Arctic was noted to be the wettest on the record.
For oceans it observed, “Plankton blooms — the base of the marine food chain — continue to increase in all Arctic regions, except for the Pacific Arctic, throughout the observational record of 2003–2024.”
However, in 2024, lower-than-average values were dominant across much of the Arctic, it noted.
The report stated that the Arctic migratory tundra caribou populations shrunk by 65 per cent in the past two-three decades.
The large inland Caribou herds show continuing decline or their populations remain at their lowest as per indigenous elders.
The report estimates that summer heat would increase the impact on these herds over the next 25-75 years, demanding knowledge sharing among scientists and indigenous communities for their management.
The report also pointed out that increase in wildfires over the years across North American permafrost regions has become an urgent and annual concern for Arctic residents.
These changes combined are now pushing the Arctic region into an uncharted territory, transforming it from a global carbon sink to a source of carbon dioxide as the region continues to emit methane.
The report said the changes would continue for coming decades and may prove devastating for some plant and animal species.
“Many of the Arctic’s vital signs that we track are either setting or flirting with record-high or record-low values nearly every year,” Gerald (J.J.) Frost, senior scientist with Alaska Biological Research, Inc. and veteran Arctic Report Card author was quoted in a statement.
“This is an indication that recent extreme years are the result of long-term, persistent changes, and not the result of variability in the climate system,” he added.