Arctic Report Card 2024

NOAA/Josh M London, NMFS Research Permit #23858

The rapid pace and complexity of Arctic change demand new and strengthened Arctic adaptation and global reductions of fossil fuel pollution.

The Arctic continues to warm at a faster rate than the global average. The 2024 Arctic Report Card highlights record-breaking and near-record-breaking observations that demonstrate dramatic change, including Arctic tundra transformation from carbon sink to carbon source, declines of previously large inland caribou herds, and increasing winter precipitation. Observations also reveal regional differences that make local and regional experiences of environmental change highly variable for people, plants and animals. Adaptation is increasingly necessary and Indigenous Knowledge and community-led research programs are essential to understand and respond to rapid Arctic changes.

Following are highlights from the 2024 Arctic Report Card. View previous reports.

Surface Air Temperature

Rising surface air and ocean temperatures characterize the changing Arctic. The increase in Arctic (60-90° N) surface air temperature continues to exceed that for the planet as a whole (90° S-90° N), a phenomenon termed Arctic Amplification. Recent studies have shown that, after accounting for natural variability, the Arctic is warming approximately three times faster than the global mean based on observational data and climate model simulations since 1980. There are many documented physical indicators of a warming Arctic. Recent decades have witnessed springtime snow cover declines on Arctic lands (see essay Terrestrial Snow Cover), summer sea ice losses (see essay Sea Ice), and Greenland Ice Sheet mass loss (see essay Greenland Ice Sheet). Extreme events are also becoming more frequent and their character is changing over time (e.g., Arctic cold extremes are warming at twice the rate as pan-Arctic annual temperatures since 1979. The warming Arctic has palpable ecological impacts at various spatial scales, which have been documented in past and present Arctic Report Cards; for example, western Alaska salmon and western Arctic caribou (see essay Migratory Tundra Caribou in a Warmer Climate) populations have shown sensitivity to rising temperatures. READ MORE

Map of average air temperature across the Arctic for October 2023–September 2024 compared to the 1991–2020 average. Areas with warmer-than-average temperatures are orange and red, and areas with colder-than-average temperatures are blue.

The graph shows how yearly Arctic (red line) and global (gray line) temperatures compared to the long-term average (1991-2020) from 1900–2024. NOAA Climate.gov.

Headlines

• Arctic annual surface air temperatures ranked second-warmest since 1900.
• The last nine years are the nine warmest on record in the Arctic.
• Autumn 2023 and summer 2024 were especially warm across the Arctic, with temperatures ranking 2^nd and 3^rd warmest, respectively.
• An early August 2024 heatwave set all-time record daily temperatures in several northern Alaska and Canada communities.
• Summer 2024 across the Arctic was the wettest on record.
• Arctic (60-90° N) annual surface air temperatures for October 2023-September 2024 ranked 2^nd warmest since 1900.

Precipitation

Patterns of Arctic precipitation vary strongly both regionally and seasonally, with very dry (even polar desert conditions) over much of the Canadian Arctic Archipelago and central Arctic Ocean contrasting with much wetter conditions over the Atlantic side of the Arctic. Locally, precipitation is strongly boosted by forced uplift of air masses by orography (orographic precipitation). Interannual variability in Arctic precipitation relates to variations in the passage of cyclones and their warm and cold fronts, as well as convective precipitation, which is caused by rising warm, moist air and mostly restricted to land areas in summer when there is strong surface heating but can also occur over the ice-free ocean in some circumstances. Reflecting such variability, the October 2023-September 2024 water year for the Arctic region poleward of 60° N was characterized by large regional anomalies in precipitation, notably in autumn and summer. During 1950-2024, pan-Arctic precipitation exhibits an upward trend in annual means, and is seasonally most pronounced for autumn and winter. In this essay, water year seasons are defined as autumn (October-December), winter (January-March), spring (April-June), and summer (July-September). READ MORE

On the map, blues and greens shows locations where the heaviest 5-day winter precipitation events in 2024 ranked in the top 10 wettest events on record (1950-2023).  The graph shows winter precipitation each year from 1950–2023 from two data sources, both confirming a long-term increase.

NOAA Climate.gov.

Headlines

• Summer (July-September) 2024 precipitation averaged across the pan-Arctic (poleward of 60° N) was at a record high.
• During 1950 through 2024, annual Arctic precipitation has increased, and the increase is most pronounced in winter.
• During October-December 2023 there was below-average precipitation over the East Greenland and Barents Seas and above-average precipitation extending from the U.K. eastward into Eurasia.

Terrestrial Snow Cover

Many Arctic land surface processes are directly influenced by snow cover from autumn through spring, including the surface energy budget, ground temperature regime, permafrost, and terrestrial and freshwater ecosystems. Even following the snow cover season, the influence of spring snow melt timing persists through impacts on river discharge timing and magnitude, surface water, soil moisture, vegetation phenology, and fire risk. READ MORE

Map showing the length of the 2023-24 snow season across the Arctic ranked from shortest to longest in the recent record (1998-2024). Five-year average June snow cover extent since 1967 compared to the 1991-2020 average. Late-spring snow cover has declined across the North American Arctic.

NOAA Climate.gov.

Headlines

• Snow accumulation during the 2023/24 winter was above the 1991-2020 average across both the Eurasian and North American Arctic.
• Early snow onset and delayed spring melt resulted in a longer than average snow season over much of the Eurasian Arctic.
• Over North America late snow onset and early spring melt resulted in the shortest snow season seen in 26 years over portions of central and eastern Arctic Canada.
• Compared to historical conditions, Arctic snow melt over the past 15 years has commonly occurred 1-2 weeks earlier throughout May and June over both Eurasia and North America.

Sea Surface Temperatures

Arctic Ocean sea-surface temperatures (SSTs) in the summer are primarily influenced by the amount of incoming solar radiation absorbed by the sea surface and by the flow of warm waters into the Arctic from the North Atlantic and North Pacific Oceans. Solar warming of the Arctic Ocean surface is influenced by the sea-ice distribution (with greater warming occurring in ice-free regions), cloud cover, and upper-ocean stratification. Inflows of relatively warm Arctic river waters can provide an additional heat source in coastal regions.

Arctic SST is an essential indicator of the strength of the ice-albedo feedback cycle in any given summer sea-ice melt season. As the brighter sea-ice cover decreases, more incoming solar radiation is absorbed by the darker ocean surface and, in turn, the warmer ocean melts more sea ice. Marine ecosystems are also influenced by SSTs, which affect the timing and development of primary production cycles, as well as available habitat. In addition, higher SSTs are associated with delayed autumn sea ice freeze-up and increased ocean heat storage throughout the year. An essential point for consideration, however, is that the total heat content contained in the ocean surface layer (i.e., the mixed layer) depends on the mixed-layer depth; a shallower mixed layer with higher SSTs could contain the same amount of heat as a deeper mixed layer with lower SSTs. We focus only on SSTs here and do not quantify ocean heat content (in the mixed layer and in deeper warm layers) due to a lack of in situ observations. While pan-Arctic assessments are limited by a lack of observations, particularly in the boundary regions of the Arctic basin, global climate model studies suggest an increasing role for ocean heat content in accelerating Arctic sea-ice loss (e.g., Oldenburg et al. 2024). READ MORE

Linear sea-surface temperature (SST) trend (°C/yr) for August of each year from 1982 through 2024. The trend is only shown for values that are statistically significant at the 95% confidence interval; the region is shaded light gray otherwise.

White shading is the August 2024 mean sea-ice extent, and the black line indicates the August 1991-2020 median ice edge. The dashed blue circle marks 65° N, and other solid blue line boundaries delineate the Barents, Beaufort, and Chukchi seas.

Headlines

• August 2024 mean sea surface temperatures (SSTs) were ~2-4°C warmer than 1991-2020 August mean values in most Arctic Ocean marginal seas.
• Anomalously cool August 2024 SSTs (~1-4°C cooler) were observed in the Chukchi Sea.
• August mean SSTs show warming trends for 1982-2024 in almost all Arctic Ocean regions that are ice-free in August, with mean SST increases of ~0.3°C per decade in the region north of 65° N.

Arctic Ocean Primary Productivity: The Response of Marine Algae to Climate Warming and Sea Ice Decline

Arctic marine primary productivity (the conversion of dissolved inorganic carbon into organic material by photosynthetic organisms) forms the foundation of the marine food web and plays a critical role in global carbon cycling. It is highly sensitive to changes in sea ice cover, ocean temperature, and nutrient availability, all of which are altered by ongoing climate change. Marine primary productivity in the Arctic varies significantly across different regions, influenced by local oceanographic conditions and the timing of sea ice retreat.

Recent in-situ observations reveal a complex picture: Although primary productivity has been boosted in many regions by thinner and more transparent sea ice, expanded ice-free areas, and enhanced nutrient upwelling, the highest localized productivity is still associated with the retreating ice edge and lipid biomarker studies indicate that sea ice derived organic material is still critical on a year-round basis in Arctic ecosystems. Another complexity is that increased stratification and changing species compositions do not necessarily lead to long-term increases in primary production. The diverse sectors of the Arctic, from the Atlantic-influenced Barents Sea to the Pacific-dominated Chukchi Sea, each respond uniquely to these changes, underscoring the need for region-specific analyses.

The ongoing transformations in sea ice cover and ocean temperatures continue to reshape the patterns of primary productivity, highlighting the dynamic nature of the Arctic marine environment and the importance of sustained, accurate observations. READ MORE

Headlines

• Satellite estimates of ocean primary productivity (i.e., the rate at which marine algae transform dissolved inorganic carbon into organic material) show lower values for 2024 (relative to the 2003-22 mean) for six of nine regions assessed across the Arctic.
• All regions, except for the Amerasian Arctic (namely the Chukchi Sea, Beaufort Sea, and Canadian Archipelago), continue to exhibit positive trends in ocean primary productivity during 2003-24, with the largest percent change in the Eurasian Arctic (+57.3%), Barents Sea (+20.5%), and Sea of Okhotsk (+13.5%).
• While lower-than-average values of annual ocean primary productivity were dominant across much of the Arctic for 2024, higher-than-average values were observed in eastern Hudson Bay, the Canadian Archipelago, and subareas of the Kara and Laptev Seas.

Sea Ice

Arctic sea ice is the frozen interface between the ocean and the atmosphere. It reduces the absorption of solar energy because of its high albedo relative to the darker open ocean surface. As a physical barrier, it modifies the heat and moisture transfer between the atmosphere and ocean. Sea ice plays a key role in polar ecosystems, providing an essential habitat for marine life and modulating the biogeochemical balance of the Arctic. The sea ice cover has long played a practical and cultural role in Indigenous communities of the North. Historically, the presence of sea ice limited national and corporate activities in the Arctic, but sea ice decline is allowing an increase in maritime traffic and drives reevaluation of resource extraction and national security activities in the Arctic.

Ice freeze-up in winter 2023/24 was relatively rapid compared to recent years, particularly in the East Siberian and Laptev Seas. The autumn and winter sea ice growth rates brought the ice cover nearer to, but below, average in those months. The extent remained below average through spring, before starting a rapid decline in June. READ MORE

March (red) and September (blue) total extent for 1979-2024, multi-year September extent (green) for 1984-2024 and linear trend lines (dashed lines). The Arctic Ocean region map is inset in the bottom left.

Headlines

• Sea ice extent in September 2024 was the 6^th lowest in the satellite record (1979 to present); the last 18 September extents (2007-24) are the 18 lowest in the record.
• The long-term negative trends in total extent and the amount of older, thicker ice continued. The more recent period since 2007 has been characterized by low extent, but without a significant trend.
• Average sea ice thickness for winter 2023/24 winter was lower than the previous winter, and close to the 2011-23 average thickness; volume at the end of the 2022/23 winter was nearly the same as the previous year.

Tundra Greenness

The Arctic tundra biome occupies Earth’s northernmost lands, covering a 5.1 million km² area that encircles the Arctic Ocean and is bound to the south by the boreal forest biome. Arctic tundra ecosystems are experiencing profound changes as vegetation and underlying permafrost soils are strongly influenced by rising air temperatures and the rapid decline of sea ice. By the late 1990s, an increase in the productivity of tundra vegetation became evident in global satellite observations, a phenomenon that continued and soon became known as “the greening of the Arctic.” Arctic greening is dynamically linked with Earth’s changing climate, seasonal snow, permafrost, and sea-ice cover, and remains a focus of multi-disciplinary scientific research. READ MORE

Circumpolar MaxNDVI anomalies for the 2024 growing season relative to mean values (2000-24) from the MODIS MCD13A1 v6.1 dataset. The 2024 mean August sea-ice extent is indicated by light shading.

Photos by G. V. Frost (upper row and lower right) and M. J. Lara (lower left).

Headlines

• In 2024, the circumpolar mean maximum tundra greenness value was the second highest in the high-resolution 25-year MODIS satellite record, continuing a sequence of record or near-record high values since 2020.
• Tundra greenness reached a record high value over the North American Arctic, while the value in the Eurasian Arctic was sixth highest in the MODIS record.
• The “greening of the Arctic,” first reported in the late 1990s as an increase in the productivity and abundance of tundra vegetation due to rapid warming and sea-ice decline, is an ongoing phenomenon evident in all available long-term satellite records.

Arctic Terrestrial Carbon Cycling

The terrestrial Arctic region has been a carbon sink for thousands of years, meaning that there has been a net removal of carbon dioxide (CO₂) from the atmosphere by plants and storage as organic carbon in soils and permafrost (perennially frozen ground). Climate warming can stimulate plant productivity and growth, resulting in enhanced rates of CO₂ removal from the atmosphere. At least 1.4 to 1.6 trillion tonnes of carbon have accumulated in terrestrial soils and permafrost across the region. Despite increased plant growth and CO₂ uptake, recent indicators suggest that some locations in the Arctic are becoming a net source of carbon to the atmosphere. Increasing surface air temperatures are causing permafrost to warm and thaw. Once thawed, permafrost carbon can be decomposed by microbes and released into the atmosphere as greenhouse gasses, CO₂ and methane (CH₄). In addition to changes in plant and microbial processing of carbon, disturbances, such as wildfire, are resulting in pulse releases of CO₂ and CH₄ that may shift the Arctic from a net carbon sink to a source. READ MORE

Mean annual ground temperature (°C) at depths of 15 m (Interior Alaska) or 20 m (North Slope) below the surface at measurement sites across Alaska.

Map and infographic credit: NOAA/Sarah Battle. Salmon illustrations credit: Katie Kobayashi.

Headlines

• When including wildfire emissions, the Arctic tundra region has shifted to a carbon dioxide (CO₂) source and is a consistent methane (CH₄) source.
• In 2024, permafrost temperatures were the highest on record at nearly half of Alaska long-term monitoring stations. On average, the year represented the second-warmest permafrost temperatures on record for Alaska.
• Wildfires in North American permafrost regions have increased since the mid-20^th century, and circumpolar wildfire emissions have averaged 207 teragrams of carbon (Tg C) per year since 2003. 2024 was the second highest year for wildfire emissions north of the Arctic Circle.

Caribou in fall range of the Western Arctic Herd of Alaska.

NPS/Kyle Joly

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Migratory Tundra Caribou in a Warmer Climate

Climate influences almost every aspect of caribou ecology, which means the Arctic’s rapid warming will have far-reaching, cascading, and complex impacts. The Arctic climate is strongly regional, such as differences between coastal and interior climates. Besides climate, geological influences on vegetation add to the regional differences which, in turn, complicate predicting how cold-adapted caribou (and their Eurasian counterpart, wild reindeer) can balance beneficial and adverse impacts of a warmer climate. Caribou spend about 3/4 of their day foraging and digesting, so how climate interacts with forage quality and quantity is key. However, climate impacts on arctic vegetation are complex; grasses, sedges and shrubs are likely to increase while many plant groups are relatively resilient to climate change. READ MORE

Trends and herd size status among migratory tundra caribou herds since peak numbers in the 1990s and early 2000s.

Headlines

• Arctic migratory tundra caribou populations have declined by 65% overall over the last 2-3 decades. More recently, the relatively smaller coastal herds in the western Arctic are showing signs of recovery while the larger inland herds are either stable or continuing to decline.
• Warmer summer and fall temperatures, changes in winter snowfall, and an increasing human footprint collectively stress Arctic caribou, altering their distribution, movements, survival, and productivity.
• The extent of recent herd declines and onsets of recoveries varies regionally, consistent with regional climate trends. Arctic regions of greatest projected summer warming are projected to see the largest continued population declines.
• Sharing knowledge is essential, as those charged with managing caribou endeavor to more fully understand climate impacts on herd health and implement strategies that encourage herd growth, while accommodating the cultural, nutritional, and spiritual relationships northern people have with caribou.

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Ice Seals of Alaska

Climate change in the Arctic is expected to affect sea ice-associated seal populations, or “ice seals,” by reducing sea ice extent and the length of time sea ice is available for resting, pupping, pup rearing, and molting . Four species of ice seals occupy the Bering, Chukchi, and Beaufort Seas, west and north of Alaska, and are harvested by Alaska Natives for subsistence: ringed (Pusa hispida), bearded (Erignathus barbatus), spotted (Phoca largha), and ribbon seals (Histriophoca fasciata). Ringed and bearded seals were listed as ‘Threatened’ under the Endangered Species Act (ESA) in 2012 due to concerns with predicted sea ice decline over the next century. Current populations of all four species are large (>100,000s) and the subsistence harvest for all four species is sustainable. READ MORE

A graph of blubber thickness compared to average (dots show the average, bars shows the 95% confidence range) since the 1960s in four types of ice seals harvested by Alaska Natives. Following declines in the 2010s, the body condition of ringed, bearded, spotted, and ribbon seals has recovered.

The map shows the locations (red squares) around the Pacific Arctic where hunters harvested the seals. NOAA Climate.gov.

Headlines

• Ice seal populations in the Pacific Arctic (ringed, bearded, spotted, and ribbon seals) remain healthy.
• Monitoring the subsistence harvest since the 1960s shows no sustained change in body condition, a stable or younger age of maturity, high pregnancy rates, and pup survival past weaning.
• As predicted with warmer water, fewer ringed seals are eating Arctic cod, and more are eating saffron cod; however, no concurrent changes in health are evident.

About the Arctic Report Card 2024

The Arctic Report Card (ARC) has been issued annually since 2006. It is a timely and peer-reviewed source for clear, reliable, and concise environmental information on the current state of different components of the Arctic environmental system relative to historical records. The ARC is intended for a wide audience, including scientists, teachers, students, decision-makers, and the general public.

ARC2024 contains 12 essay contributions prepared by an international team of 97 scientists from 11 countries. An independent peer review of ARC2024 was organized by the Arctic Monitoring and Assessment Programme (AMAP) Secretariat. The ARC is classified as a NOAA Technical Report and is archived within the NOAA Library Institutional Repository.

Moon, T. A., M. L. Druckenmiller, and R. L. Thoman, Eds., 2024: Arctic Report Card 2024.