There’s Trouble a Brewin’ in the Marriage between the Atmosphere and the Ocean
The cooling patch of ocean south of Greenland Credit: Nature Climate Change
By Michael Coppola and Nancy Lazar
What
drives a significant part of the planet’s weather and climate and is
responsible for feeding a good portion of the world? It is the Atlantic
Meridional Overturning Circulation or AMOC. This is the movement of surface
and deep ocean water by a convection cell between the warm equatorial
Simply
speaking, warm surface water in the tropics flows north; when it reaches the
colder northern latitudes it becomes denser, sinking down when it reaches the
glacial area of the
Scientists who study the AMOC have observed that
as the atmosphere and the oceans warm, the AMOC slows down. This is in part
because as more fresh water from melting glaciers enters the Northern Arctic
waters it reduces the density of the sea water and hinders the downward sinking
of water, disrupting the convection cell.
As reported in a study published in the journal Nature, “The Atlantic Meridional Overturning Circulation has declined in strength by 15 percent since the mid-20th century to a new record low." That’s a decrease of 3 million cubic meters of water per second, the equivalent of nearly 15 Amazon Rivers. Jon Robson, a researcher at the University of Reading, and one of the study’s authors explained that the last 100 years has been its lowest point for more than a thousand years.
When the AMOC slows down things happen that are detrimental to the planet
Here are some examples:
The AMOC and
all other ocean convection cells, such as the
These
currents also bring much needed nutrients to enable phytoplankton and
zooplankton to thrive in the oxygen-rich cold water in the north. The process
of mixing the southern ocean waters, which are rich in nutrients with colder
water of the northern oceans, enables the existence of the productive fisheries
of the northern ocean. This creates a fishery that provides 40% of the world’s
seafood. What might be the most devastating result of a slowing or even a
possible stop to the AMOC? If
insufficient nutrients reach the
A
slowing of the AMOC can raise the sea level along the northeast coast of
Scientists predict the AMOC circulation will
only weaken further as climate change advances and the change may not be slow and
steady. Studies from the planet’s history suggest
that such a sudden change in the North Atlantic has occurred many times in the
past and as recently as about 13,000 years ago. One of the study’s authors,
Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in
Germany states “I think in the long run … Greenland will start melting
even faster, so I think the long-term prospect for that ocean circulation
system is that it will weaken further.”
If it's not time for divorce lawyers for the atmosphere and the AMOC, maybe a little advice from counseling would help? As this article and previous articles have shown Climate Change is moving faster than originally predicted so we must take rapid steps to reduce the amount of global greenhouse gasses. The best way to achieve this is through aggressive conservation. WWII proved that we can endure rationing and sacrifice for the greater good. We can shutdown high C02 generation for more efficient plants if we all commit to using less energy on a daily basis.
As noted in a previous Planet Earth Needs You blog we can reduce methane, a highly potent greenhouse gas, by cutting out the source from animal agriculture. If we all eat less meat and shrink that sector we will go a long way to mitigating this crisis of global warming.
References
https://www.climatecentral.org/news/climate-change-jamming-critical-heat-conveyor-18810
https://science.sciencemag.org/content/298/5602/2374
https://www.nature.com/articles/ncomms7346
Comments
Post a Comment