Not if, but when: The coming North Atlantic deep freeze

In recent years scientists have been watching and measuring the flow of the Atlantic Meridional Overturning Circulation, (AMOC), what Americans often refer to as the Gulf Stream though that flow is only part of this vast ocean current. For a long time the belief was that the AMOC—which transports heat from the tropics to Greenland, Iceland and northern Europe and makes them much warmer than they would otherwise be—would continue to flow with no discernible end date.

But two recent studies suggest that the current could not just slow, but stop altogether sometime around mid-century thereby lowering temperatures dramatically in northern Europe. The earlier study from 2023 suggests a collapse could occur sometime between 2025 and 2095, a wide interval, but actually the blink of an eye in geologic time. The more recent study released this year used a more sophisticated model and narrowed the window from 2037 to 2064. Both studies put the most likely date of collapse at mid-century (either 2050 or 2057).

Rising temperatures due to climate change are resulting in vastly increased meltwater coming from the the Greenland ice sheet—which on average is over one mile thick. This meltwater is being dumped into the North Atlantic where it reduces the salinity of the ocean water, thus making the water less dense. This reduced density appears to be slowing the current where it dives deep into the ocean, a dive that is essential for the current to continue to flow.

Taking a short break - no post this week

I am taking a short break this week and plan to post again on Sunday, August 25.

Dark oxygen: We don't know what we don't know

Last month some very clever scientists published their findings on oxygen production on the seafloor. What is astonishing is that previously we've believed that free oxygen in the atmosphere and dissolved in the oceans had come almost exclusively from plants performing photosynthesis. But here at the lightless abysmal depths these scientists found levels of oxygen consistent with production of what they call "dark oxygen." The discovery is yet another example of that eternal verity that we don't know what we don't know.

The findings—which were partly funded by deep sea mining interests—are now instantly under attack by those same interests. The reason can be found in the mechanism by which the oxygen is being produced. The scientists believe that the very minerals which the deep sea miners want to hoover up off the ocean floor are the ones facilitating what they call "seawater electrolysis." Electrolysis is the process of freeing the hydrogen and oxygen atoms that make up water from each other using an electric current. The hypothesis is that electrolysis is taking place spontaneously as a result of the presence of copper and manganese nodules lying on the seabed.

The implications are profound if it turns out that this is a significant contributor to free oxygen on the planet. No one knows for sure, and the mechanism producing the oxygen has not yet been verified by other researchers. And that verification is precisely what the scientists say needs to happen. But that, of course, might delay any deep sea mining until the implications of that mining for dark oxygen are clarified.

Who will pay for the cost of overheated humans in the age of climate change?

Hey there, it's hot in here

SOURCE: The Walt Disney Company (News Release)

 

 

 

One of the inevitable consequences of climate change is that in most places temperatures will rise. This may seem welcome (at least for a while) in cooler regions, but most people live in temperate and tropical zones. When the Walt Disney Co. built Disney World in central Florida—it opened in 1971—the location was warm and sunny three seasons of the year, even if a little hot in the summer.

Now, central Florida is not just a little hot in the summer; it has become unbearable for many of Disney World's employees who must work outside, some of them wearing heavy costumes while playing such roles as Mickey Mouse, Goofy, and Disney princesses. With the local heat index rising above 100 degrees F, outdoor workers are becoming overheated and complaining about lack access to shade, water and adequate break time. Recently, a broken air-conditioner in a waiting room for actors led to two fainting incidents—after which the air-conditioner was repaired.

Of course, Disney workers aren't the only ones suffering from overheating. Those working in farm fields aren't there to entertain people, but to do heavy work in the noonday sun. The Environmental Defense Fund (EDF) reports that farmworkers suffer heat-related mortality at rates 20 times those of other workers. The EDF calculates that 2 million farmworkers in the United States now face 21 days a year during which heat conditions are unsafe. But climate change is a moving target. If global greenhouse gas emissions peak at mid-century, that would add an additional 18 days of unsafe heat conditions.