Research reveals that carbon emissions are increasing in the Arctic Ocean due to global warming

The Mackenzie River approaches the Arctic Ocean. Epic Photos / iStock / Getty Images Plus

of arctic ocean It may be the smallest ocean on Earth, but it is a significant carbon sink, absorbing up to 198 million tons of carbon per year, according to a NASA press release.

However, recent study Researchers have shown that thawing permafrost and carbon-rich runoff from Canada’s Mackenzie River are triggering some of Earth’s northernmost oceans to release more carbon than it absorbs. .

“Since the 1970s, the Arctic has warmed three times.[s] It causes major changes in the water cycle faster than anywhere else on Earth. This warming is dramatically changing Arctic watersheds and rivers, which play an important role in shaping the physical and biogeochemical environment of the coastal AO. [Arctic Ocean]” wrote the study authors. “Recent studies have shown that carbon attributable to permafrost in the Mackenzie River estuary was also observed in early spring and early summer, when normally only modern (i.e. young) organic matter is observed, and is now This highlights the ongoing rapid warming of the Arctic.”

The study, “Biogeochemical river runoff drives intense carbon dioxide emissions along the Arctic coast,” was published in the journal Geophysical Research Letters.

The study examines how scientists use computer modeling to study rivers like the Mackenzie River, which feeds into the Beaufort Sea, NASA said. In recent years, rising temperatures have led to increased melting and dissolution of the Mackenzie River system and its delta landforms and waterways.

The Mackenzie River serves as a mineral, inorganic, and organic river in this wetland region of Canada’s Northwest Territories. This material then flows into the Beaufort Sea as dissolved sediment and carbon. Some of the carbon is released into the atmosphere as a gas.

Scientists previously thought the southeastern Beaufort Sea was a “weak to moderate” carbon sink, absorbing more carbon than it emitted, but the region’s remoteness This was far from certain due to the lack of data. .

To fill in the gaps in information, the researchers employed ECCO-Darwin, an ocean biogeochemical model developed at NASA’s Jet Propulsion Laboratory in Southern California and the Massachusetts Institute of Technology. The model incorporated nearly all of the available ocean observations collected over his 20 years by satellite and ocean-based instruments.

The international research team used the model to simulate freshwater runoff and its elements, including nitrogen, silica, and carbon, from 2000 to 2019.

The researchers found that river discharges in the Beaufort Sea are causing intense outgassing, tipping the carbon budget and releasing 1.3 million tons of net carbon dioxide annually. This is roughly equivalent to the annual emissions of 28,000 gas-powered cars. car. There are seasonal variations in the amount of carbon released into the atmosphere, with more released from rivers and during warmer months when there is less sea ice to cover and trap the gas.

But while some changes occurring in the warming Arctic since the 1970s have promoted increased regional carbon emissions, others have led to increased carbon uptake.

According to NASA, rivers are flowing faster as ice and snow melt and the land in the Arctic melts. In doing so, more organic matter from peatlands and permafrost is leached into the ocean. However, as sea ice shrinks, microscopic phytoplankton near the sea surface are also thriving as the open ocean receives more sunlight. Like plants, these tiny marine creatures use photosynthesis to capture carbon dioxide, turn it into energy, and release oxygen.

Although the study focuses on one part of the Arctic Ocean, the findings could help shed light on larger environmental changes occurring in the region.

“With our model, we are trying to explore the real contribution of coastal margins and rivers to the Arctic carbon cycle,” said lead author of the study and a scientist at France’s Institute of Coastal Environment and Society. Clément Bertin said in a press release.

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