Hello again,
Episodes 3 and 4 of the NECC podcast, covering topics of extreme weather and the further reaching effects of climate change, are coming out soon! Tuesday and Friday of this week, respectively. We’re a bit behind, due to some of the certifications we’re trying to obtain, but we’re very excited to deliver more episodes of the NECC podcast to you via your favorite platform.
To hold you over, though, let’s get you thinking about tipping points in climate change, which is very much tied to extreme weather events that climate change also causes. Tipping points can be a variety of things, and may change a bit depending upon who you ask; generally, however, commonly agreed upon ones you’ll hear could be the rising of the global temperature above 2 degrees Celsius, the widespread death of coral reefs(this one has already happened, unfortunately…), the melting of the Greenland Ice Sheet, or the collapse of the AMOC.
The collapse of the AMOC? That one isn’t so common. The AMOC, or Atlantic Meridional Overturning Circulation (AMOC is clearly more digestible than saying that every time) describes the circulation of currents that starts and ends in the Atlantic Ocean near Greenland, passing through all 4 of the major oceans in the process. The AMOC, which circulates roughly 15 million cubic meters of water per second, has slowed down by roughly 10-15%, and may be at it’s weakest point in the past 1,000 years, according to some scientists. But how is it weakening?
Well, the melting freshwater, such as that coming from the polar regions or the Greenland Ice Sheet, go into the water. Less salt means the water doesn’t sink down as far, so a large influx of freshwater actually ends up weakening the AMOC. The water becomes less dense, sinks down less far, and brings less salt back to the region in question, which itself further slows down the AMOC, creating a positive feedback loop known as, “Salt Advection Feedback”.
What are the consequences of the AMOC collapse? Well, you’ll have to tune in to the next few episodes of the NECC podcast to find out! We’ll see you soon, but here are a few interesting articles that we sourced from about the AMOC to read for yourself, if you’d like!
-Dean
Sources: https://www.scientificamerican.com/article/is-a-mega-ocean-current-about-to-shut-down/#:~:text=Why%20is%20it%20weakening?,in%20the%20past%201%2C000%20years.
Real Climate: What is Happening in the Ocean to the AMOC? (bad URL link, sorry everyone)
https://www.wired.com/story/oceans-day-deep-ocean-current-slowdown/#:~:text=England%20says%20there’s%20evidence%20to,natural%20variability%20of%20the%20current.
https://www.nationalgeographic.com/environment/article/amoc-atlantic-ocean-conveyer-belt-climate-change#:~:text=One%20of%20those%20tipping%20points%20relates%20to,AMOC%2C%20a%20giant%20oceanic%20’conveyor%20belt’%20that