Context:

According to a recent report by the National Oceanic and Atmospheric Administration (NOAA), the Arctic tundra has now turned into a net source of greenhouse gas (GHG) emissions after millennia of acting as a carbon sink.

More on the News

• A report from the NOAA, known as the Arctic Report Card reveals that the Arctic tundra is now releasing more carbon than it absorbs, signaling a decline in its ability to act as a carbon sink.
• This shift is believed to be the first time in many millennia that the Arctic tundra has become a net emitter of GHG, particularly CO2 and methane (CH4).
• This change has major global consequences as it will further accelerate climate change, which is already affecting ecosystems worldwide. 
• Increased wildfires and rising temperatures are the two main reasons behind the dramatic transformation of this Arctic ecosystem.

Key Highlights of the Report

In the Air:

• The report highlights that the Arctic is warming four times the global rate, and that annual surface air temperatures in the Arctic in 2024 were the second-warmest on record since 1900. 
• As a result, the Arctic’s permafrost is thawing, meaning microbes in the soil are becoming active and breaking the organic matter down, releasing CO2 and CH4 into the atmosphere.
• Autumn 2023 and summer 2024 were especially warm across the Arctic, with temperatures ranking 2nd and 3rd warmest, respectively.
• The last nine years are the nine warmest on record in the Arctic. 
• Summer 2024 across the Arctic was the wettest on record. 

In the Ocean:

In September 2024, the extent of the Arctic Sea ice, which has a profound influence on the polar environment, was the sixth-lowest in the 45-year satellite record. 

Arctic Ocean regions that were ice-free in August have been warming at a rate of 0.5 degrees F (0.3 degrees C) per decade since 1982. 

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.

• In 2024, lower-than-average values were dominant across much of the Arctic. 

On the Land:

• When including the impact of increased wildfire activity, the Arctic tundra region has shifted from storing carbon in the soil to becoming a carbon source in the atmosphere. 
• Wildfire smoke adds GHG emissions to the atmosphere while also speeding up the thawing of permafrost. 
• 2023 was the worst wildfire season in the Arctic on record, and 2024 was the second-biggest year for wildfire emissions. 
• Alaskan permafrost temperatures were the second warmest on record. 
• Arctic migratory tundra caribou (reindeer) populations have declined by 65% over the last 2-3 decades.
• Snow accumulation during the 2023-2024 winter was above average across both the Eurasian and North American Arctic.
• Tundra greenness, a measure of expanding shrub cover due to warming temperatures, ranked second highest in the 25-year satellite record.

Key Suggestions 

• The Arctic Report Card suggests that the only way to reverse this change is by reducing global greenhouse gas emissions.
• Scientists stress that lowering emissions would lead to lower carbon releases from permafrost thus offering hope for the future.