The National Oceanic and Atmospheric Administration (NOAA) has released its 20th annual Arctic Report Card, detailing that the Arctic region is warming at a rate faster than the global average. The report highlights several observable environmental changes, including the discoloration of rivers, record-setting warmth and wetness, significant ice loss across glaciers and ice sheets, and the increasing presence of warmer, saltier water in the Arctic Ocean. These shifts contribute to global sea-level rise, altered weather patterns, and impacts on both aquatic ecosystems and human activities.
Overall Warming Trends
The most recent year evaluated in the report was the warmest and wettest in the Arctic's recorded history. Matthew Druckenmiller, lead editor of the report and a senior scientist at the National Snow and Ice Data Center, indicated that this continued Arctic warming contributes to global sea-level rise, altered weather patterns, and changes in commercial fisheries.
Discolored Rivers Phenomenon
Hundreds of rivers and streams across the Brooks Range in northern Alaska are exhibiting a bright red-orange hue, a phenomenon some sources describe as "rusting rivers." This discoloration is attributed to naturally occurring iron released from long-frozen ground as permafrost thaws. Observations of these discolored waters began around 2018, initially reported by local residents and pilots. Subsequent satellite imagery, water testing, and ground observations have documented the widespread nature of this occurrence across hundreds of miles in remote Alaskan areas.
Research by Josh Koch of the U.S. Geological Survey indicates that as water and oxygen penetrate melting soil, iron and other metals, such as copper and aluminum, seep into nearby streams. The discoloration often becomes apparent as these metals precipitate upon reaching the stream. Scientists are investigating the potential impacts on aquatic life, the food chain, and rural drinking water supplies, though no impacts on drinking water have been identified to date.
Glacier and Ice Sheet Reduction
The Greenland Ice Sheet experienced a loss of 129 billion tons of ice in 2023, continuing a long-term trend of mass reduction. Arctic glaciers outside Greenland have also thinned significantly since the 1950s, with Alaskan glaciers losing an average of 125 vertical feet over that period. The melting of glaciers, such as the Mendenhall Glacier near Juneau, Alaska, has resulted in glacial lake outburst floods in recent years. Globally, ongoing glacier loss contributes to rising sea levels, which increases risks of flooding, erosion, and storm surges in coastal areas.
Oceanic Changes and "Atlantification"
Warmer, saltier water is increasingly present in the Arctic Ocean near the North Pole, a process termed 'Atlantification.' This phenomenon is linked to record low sea-ice extent in the region, with the most recent year recording the lowest sea-ice extent in the 47-year satellite record.
Similar warming trends are observed in the Bering Sea, an area significant for commercial fish species like Alaska Pollock and Pacific Salmon. The warmer waters are associated with an increase in southern marine species and a decline in Arctic species, affecting both traditional hunting practices and commercial fisheries.
Report Context and Scientific Integrity
The annual Arctic Report Card is compiled by an independent network of global scientists. Its release occurs during a period of changes in federal science and climate research policy. The report discusses the effects of climate change, with at least one study noting the burning of fossil fuels as a major contributing factor. Acting NOAA Chief Scientist Steve Thur affirmed the organization's commitment to sustained observations for understanding Arctic change, and lead editor Matthew Druckenmiller noted that the report received full support from NOAA.