We all agree that the wind-driven surface currents of the Atlantic Multilayer Overturning Circulation (AMOC) carry precious warmth from the tropics to the Arctic and make the climate in Europe and North America milder. We all agree that the ocean has a huge impact on climate and is responsible for temperature changes that cannot be explained by the carbon dioxide greenhouse effect.
The AMOC is unique in that: 1) It carries tropical heat from the South Atlantic across the equator into the North Atlantic and Arctic Oceans (red current, Figure A). 2) It creates a warm Atlantic reservoir at depths of 100 to 900 meters in the Arctic Ocean, capable of melting all sea ice more than 4 times (Figure C). 3) Because the Atlantic Ocean is saltier than the Pacific Ocean, as it cools it becomes dense enough to sink to the ocean floor, creating pressure that drives deep return currents back to Antarctica (blue ocean current, Figure A).
As the AMOC slows down, less heat is transported to the Arctic. Now, a growing ocean cold spot south of Greenland suggests the AMOC is indeed slowing down again. In defense of the global warming narrative, climate alarmists such as Stefan Ramstorff and Michel Mann advance the idea that global warming is causing temperatures to drop and that rising CO2 emissions will soon lead to Catastrophic AMOC collapse, freezing Europe and disrupting global climate. But changes in AMOC heat transport have occurred over thousands of years and are independent of changes in carbon dioxide concentrations.
Most scientists believe that differential AMOC heat transport causes a global see-saw effect that contributes to Atlantic Multidecadal Variability (AMV) (Figure B). As the AMOC strengthens, it also steals more warmth from the South Atlantic. The North Atlantic then warms and the South Atlantic cools. During the 1930s and 1940s, the North Atlantic warmed and Arctic sea ice retreated, similar to what is observed today. In the 1970s and 1980s, the AMV cycle cooled the North Atlantic and caused Norwegian glaciers to grow, prompting some scientists to warn that we were heading toward a new ice age. In the 1990s, as the AMV cycle and the Atlantic Ocean warmed again, a new concern was global warming. Blind scientists attribute the effects of AMOCs to rising carbon dioxide concentrations. Most people ignore the fact that Arctic sea ice melts primarily where warm Atlantic waters enter the Arctic, and downplays the AMOC see-saw effect that redistributes heat and causes a simultaneous increase in Antarctic sea ice (Figure D).
Still, these changes gave drama queens and eco-junkies like Roger Hallam ammunition to launch Extinction Rebellion and the Stop Oil movement. Ignorant politicians are quick to hype up climate change as a crisis by giving government grants to alarmist scientists, demonizing carbon dioxide, and blaming fossil fuels. To manipulate our fears, alarmist scientists such as Katharine Hayhoe falsely claim that the world is warming faster than ever, rising by 1.1°C (2°F) since 1850. This statement dishonestly ignores climate history and the impact of the AMOC.
During the last glacial period, carbon dioxide concentrations were about 180-200 parts per million (ppm) and temperatures were about 11 degrees Fahrenheit (6 degrees Celsius) cooler than today. However, related to the AMOC effect, the Arctic experienced 25 Dansgaard-Oeschger (DO) events that warmed Greenland by 18 to 27 degrees Fahrenheit (10 to 15 degrees Celsius) in just a few decades (Figure E, red numbers Mark each DO event) for nearly half of the glacial period). Such rapid warming can only be explained by sudden ventilation of Atlantic heat transported through the AMOC and stored in the Arctic Ocean.
As is the case today, the warm salty Atlantic water was insulated from surface ice and the atmosphere by a layer of fresh water, preventing the heat of the warm Atlantic water from rising to the surface. As glaciers grow, the air becomes drier and the flow of freshwater into the Arctic decreases, allowing warm Atlantic water to rise closer to the surface. Coupled with the increase in AMOC, which brings more heat, Arctic sea ice melts and its stored heat is released, rapidly increasing temperatures.
Today's ebb and flow of the AMOC, similar to but less dramatic than during dissolved oxygen events, is causing Arctic sea ice to melt, releasing stored heat. Subsequently, Arctic temperatures are rising 2 to 4 times faster than elsewhere. The current slowdown in the AMOC is simply part of the natural oscillatory dynamics. The current economic slowdown will soon increase Arctic sea ice and lower temperatures naturally, without the need for crazy net-zero mandates or Gates’ sun-blocking efforts. The economic slowdown doesn't mean we're all going to die like the catastrophic stories told by ecological loons and alarmist scientists. Whether we burn more or less fossil fuels, it doesn't change the AMOC. Maybe then we'll realize that life-giving carbon dioxide is not our enemy!
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