Did you know that 2024 was the hottest year on record?
The National Oceanic and Atmospheric Administration (NOAA) and other meteorological organizations released their annual reports on global temperature rise. They unanimously found that the Earth had warmed 1.5 degrees Celsius (°C) above temperatures in the 1800s, before fossil fuels were burned frequently.
The Paris Climate Agreement calls on countries to limit temperature increase to below 2°C or 1.5°C because of the potential consequences it poses, such as harm to biodiversity, increased heat waves, and natural disasters.
However, the most concerning impact of global warming is the implications it could have on the AMOC.
What Is AMOC? Why Does It Matter?
The Atlantic Meridional Overturning Circulation (AMOC) is responsible for water circulation from north to south and back in the Atlantic Ocean.
The ocean water circulates by currents, which are influenced by changes in temperature or even saltiness. This process is called thermohaline circulation, and AMOC is a vital part of it.
AMOC transports warm waters from the tropics northward, warming the climate of Western Europe. By the time it reaches the Arctic, the water is significantly cooler and denser (as evaporation makes the water saltier), causing it to sink. This cold, dense water flows southwards along the ocean floor.
Based on a recent study, former NASA scientist James Hansen warned the public about the impact of global warming on the Arctic. Hansen explains that the melting Arctic ice sends more fresh water into the North Atlantic, which could weaken the AMOC. This, in turn, will impact the circulation needed to warm the waters of Western Europe.
The Implications of AMOC Shutdown
The study suggests that an AMOC shutdown could lead to rising sea levels along the East Coast and bring extreme climate change to parts of Europe that could harm agriculture production.
The AMOC provides the system that delivers heat to the Northern Hemisphere, so if it were to stop, water would remain in the Southern Hemisphere and accumulate, causing sea level rise. In addition, the potential shutdown could change the precipitation patterns of the Amazon; this would ultimately disrupt the ecosystem of the Amazon rainforest.
The exact timeline of a possible AMOC shutdown is unknown, but the threat is enough to raise serious concern among climate scientists worldwide. Though the AMOC shutdown could have detrimental effects, scientists like Hansen work to provide policy recommendations to reduce factors contributing to global warming.
The climate models created by scientists and institutions allow the public to understand the gravity of the issue, and they encourage individuals to educate themselves on pressing world issues.
Sources: NPR, Inside Climate News, NOAA, Science.org
