Maggie Maue is a fourth year Communications Major at UC Davis interning at Cool Davis, a lifelong dancer, and a Sacramento native. Maggie joined Cool Davis because she “wanted to go deeper and see what else I could do to help the environment. I think that starting locally and community-based is a great idea since I believe that most change starts small.”

The catastrophic, widespread impacts of climate change can no longer be ignored. The Atlantic Meridional Overturning Circulation (AMOC), a global system of ocean currents that is integral to much of the planet’s temperature regulation, is at the weakest it has been in 1,000 years and might collapse sooner than scientists previously thought. According to a study published last year in Nature Communications, it is possible that the AMOC could collapse anywhere between 2025 and 2095 but is expected to collapse around mid-century based on current models.

Not with a whimper, but a bang

This collapse will cause a widespread, devastating upheaval of current climate conditions. Europe will become 5 to 10 degrees cooler, weather patterns in the southern hemisphere will shift, flood risk will increase in the American Southeast, and sea levels will rise dramatically. In a 2023 interview with Oceanus, oceanographer Nicholas Foukal explained that “‘These effects would directly impact agriculture, food prices, transportation, construction, disease, immigration, and political stability.’ ”

The AMOC’s collapse will be the most noticeable — and abrupt — effect of climate change to date. It is speculated that part of the AMOC’s weakening is due to Earth’s natural climate fluctuations, but rapid thinning and loss of ice in the Arctic regions due to man-made emissions is thought to be the main culprit.

An uncertain future

Clearly, we need to act fast in order to reduce our carbon output, but how long do we have before it is too late? Although it is well established that the AMOC will eventually collapse, there is a lot of uncertainty about when it will happen. It is difficult to create a model that considers every factor that could contribute to the weakening of the AMOC and the temperature changes associated with it. More data is also needed to determine whether or not these are natural fluctuations of the current or bigger, more long-term changes (the AMOC has only been continuously monitored since 2004). Some scientists even believe that it is questionable that the AMOC will collapse within this century.

However, in the same interview with Oceanus, oceanographer Jiyan Yang emphasized that “‘Even if we don’t yet have the observational data sufficient to prove whether this is a shutdown or not, we should not wait for another 50 years to collect the data — because that might be already too late.’”

 

Schematic of key AMOC‐related components of the North Atlantic Ocean (modified from García‐Ibáñez et al., 2018). Abbreviations are as follows: NRG = Northern Recirculation Gyre; LC = Labrador Current; DWBC = Deep Western Boundary Current; IC = Irminger Current; EGIC = East Greenland‐Irminger Current. Three source waters for North Atlantic Deep Water are noted: LSW = Labrador Sea Water; ISOW = Iceland‐Scotland Overflow Water; DSOW = Denmark Straits Overflow Water. Box indicates the U.S. East Coast region. Source: https://www.researchgate.net/figure/Schematic-of-key-AMOC-related-components-of-the-North-Atlantic-Ocean-modified-from_fig2_335091674

Sources

https://oceanservice.noaa.gov/facts/amoc.html

https://www.whoi.edu/oceanus/feature/whats-happening-with-the-amoc/

https://www.scientificamerican.com/article/is-a-mega-ocean-current-about-to-shut-down/

https://www.cnn.com/2024/02/09/climate/atlantic-circulation-collapse-weather-climate/index.html

https://www.nature.com/articles/s41467-023-39810-w

https://www.nature.com/articles/s41467-023-40848-z

https://www.researchgate.net/figure/Schematic-of-key-AMOC-related-components-of-the-North-Atlantic-Ocean-modified-from_fig2_335091674