Mercury Rising

  

If you wince at the mercury (symbol Hg) in your tuna or salmon, you’re going to find one more reason to fear the acceleration of climate change. A liquid metal at most temperatures on Earth, mercury is a deadly neurotoxin that can accumulate in your body, slowly killing you… or if a large dose is ingested, make that instantaneous. Mercury enters cellular tissue and binds to and inhibits the function of enzymes and proteins critical for nerve cell function. But as the above illustration shows, mercury is in the environment, from industrial waste as well as from natural sources.

Fortunately, vast pools of that toxic metal are separated from most of us, frozen within polar ice and permafrost (tundra). Unfortunately, that ice and permafrost are melting faster than most of us know… and leaching that mercury out into the oceans and surrounding lands. Sea creatures in those cold waters, from fish to penguins, seals, polar bears as well as the vast vegetation undersea, soak up mercury… with obvious results. Writing for IFLScience (August 16th), Tom Hale, explains some of the harsh details, which impact both our polar regions:

“A ‘giant mercury bomb’ is ticking in the Arctic. As the world warms with climate change, mercury that’s been stored in the permafrost for thousands of years threatens to be set free into the environment, potentially wreaking havoc on wildlife and human life… In a new study, scientists measured how much mercury could potentially seep into the ecosystem from thawed permafrost around the Yukon River.

“To find out, [these researchers] headed to two northern villages in Alaska’s Yukon River Basin – Beaver and Huslia – and took core samples from the top 3 meters (9.8 feet) of permafrost. They paired this with satellite data that shows how the Yukon River is changing course… They found that significant amounts of mercury are released when riverbanks erode, but a smaller and more variable amount is redeposited as the rivers shift.

“In conclusion, they found the mercury from the permafrost could pose an environmental and health threat to the 5 million people living in the Arctic zone… ‘There could be this giant mercury bomb in the Arctic waiting to explode,’ Josh West, study co-author and professor of Earth sciences and environmental studies at the Dornsife Research center], University of Southern California … said in a statement… [Mercury] isn’t just found in science classrooms and thermometers. The metallic element circulates in small amounts through the natural world because it’s absorbed by plants, which then die and become part of the soil. It’s especially prolific in the Arctic, where the soil becomes frozen into permafrost, locking it away for generations… ‘Because of the way it behaves chemically, a lot of mercury pollution ends up in the Arctic. Permafrost has accumulated so much mercury that it could dwarf the amount in the oceans, soils, atmosphere and biosphere combined, said West.

“It’s also a worrying problem for the northernmost parts of our planet because this region is warming up to four times faster than the global average and already feeling the sting of climate change… The threat of mercury increases as the metal accumulates in the food chain, from plants to small creatures, eventually ending up in the fish and other animals that humans eat.” Because most of the permafrost is contained in the Artic region, that area faces the greatest danger. Shortly after this study was released, a parallel study was released assessing the rate at which the polar ice caps are losing this ability to maintain cooler temperatures.

Researchers A. Duspayev, M. G. Flanner and A. Riihelä present this summary from their report entitled Earth's Sea Ice Radiative Effect From 1980 to 2023, a study funded with support from the University of Michigan (Ann Arbor) and the Research Council of Finland, and published July 17th in the Geophysical Research Letters of the AGU: “Ice that forms on the surface of the ocean (sea ice) is highly reflective of sunlight, especially in comparison with ocean water, which has very low reflectivity. Sea ice therefore cools Earth by decreasing the amount of sunlight that it absorbs. We present a measure of this planetary cooling effect and evaluate how it has changed since 1980, around the advent of consistent satellite observations of Earth's surface and atmosphere. At individual locations and times, the cooling effect depends on the amount of incoming sunlight (which varies strongly with season in polar regions), cloud coverage (which masks the underlying surface from sunlight), and the reflectivity of the sea ice and overlying snow. Averaged globally, this effect varies with the areal coverage of sea ice and has therefore weakened with shrinking ice coverage. The planetary cooling effects of Arctic and Antarctic sea ice during 2016–2023 were about 20% and 12% less, respectively, than they were during 1980–1988. Disappearing sea ice is therefore amplifying climate change by causing Earth to absorb… an additional [significant level of] solar power for each degree Celsius of global warming, a feedback that is stronger than that simulated by most climate models.” Another of climate change’s litany of little unexpected surprises to the rising tsunami of death and destruction that just keeps getting worse.

I’m Peter Dekom, and I suspect this just be a time when a different type of “Mercury in retrograde” (that otherwise traditionally and purportedly creates chaos several times a year) just might be welcome.