Extinction Events and Hydrogen Sulfide

What is hydrogen sulfide and what does it have to do with extinction events? In my last entry where I discussed James G. Anderson, I pointed out how the current behavior of the climate system will be interrupted and inherently changed by the loss of Arctic ice and the cryosphere in general. This loss of ice in sea ice, permafrost, glaciers, and frozen lakes and rivers will dramatically speed up the process of warming not only in the Arctic, but the entire Northern Hemisphere and beyond. As it does this, eventually, the temperature difference between the poles and the tropics will disappear. Without the large temperature difference, winds will be diminished, causing the world's oceans to mix less. This will cause hypoxic conditions due to less circulation and less circulation will lead to stagnation, and general anaerobic conditions will lead to the production of hydrogen sulfide leading to sulfidic oceans, also known as the Canfield Ocean. 

Understanding that the cryosphere is such an important part of the climate system is key to comprehending many of the predicaments brought on by climate change. The cryosphere is basically the "world's air conditioner" by keeping the planet much cooler than without all this ice due to the latent heat of fusion. The same amount of heat required to transform a specific amount of ice at 0 degrees Celsius to water at 0 degrees Celsius [about 334 Joules or 80 calories] will heat that same amount of water (now transformed from the ice) to 80 degrees Celsius! In other words, as long as we have ice rather than liquid water, that ice requires a LOT of energy to  become liquid, but once it is liquid, it then VERY RAPIDLY warms. Notice also that water has the highest heat capacity of liquids, meaning that it takes longer to heat (or cool) than other liquids. 

All of this brings us to a presentation by paleontologist and professor of Biology and of Earth and Space Sciences at the University of Washington, Dr. Peter Ward. This particular presentation is available in book form here and here. His studies have focused on mass extinctions (among other topics) and one part of mass extinctions that is the focus of this presentation is none other than hydrogen sulfide. This is combined with another presentation which is presented in more detail in another book here. The bottom line with regard to how this all unfolds is as follows:

A New View of Mass Extinctions

• Majority caused by RAPID global warming brought about by volcanic greenhouse gas emissions

• Stagnant oceans go anoxic

• Allow buildup of toxic sulfur bacteria

• Emission of hydrogen sulfide to atmosphere

• Loss of ozone, direct poisoning (through both hydrogen sulfide and UV radiation)

• Plant and animal life extirpated

One item that is important to understand, as James Anderson pointed out in my previous article, is the loss of ice in the climate system. This produces multiple other predicaments such as methane emissions, sea level rise (SLR), further warming, permafrost thaw, Arctic lightning, wildfires, and more. In fact, Arctic lightning is set to double this century, increasing chances for wildfires, increasing the rate of permafrost thaw, and causing increasing melting on existing ice from black carbon (soot). The sea level rise is important because of not just the loss of productive agricultural land and the coastal cities, but saltwater intrusion which causes issues for water security and even further agricultural land loss, among other things. Of course, this is just an inconvenient truth in relation to the evolution of climate change and the mass extinction which we are already a part of.

(6-21-2021) I have a new study to add to this article, highlighting the function of hydrogen sulfide in the carbon cycle, making it a negative climate feedback on geological timescales, quote: 

"Given that huge amounts of carbon are stored in dissolved organic matter - the world's oceans contain roughly as much dissolved organic carbon as there is CO2 in the Earth's atmosphere - the results of this new study are also relevant for the climate. "The volume of ocean waters completely depleted of oxygen quadrupled between 1960 and 2010. Consequently, this sulfur-based mechanism of carbon storage could influence the chemistry of the oceans in the future," says Gomez-Saez, the lead author of the study. But this negative feedback is too weak to have a noticeable impact on climate change under the current conditions, he adds. In geological history, however, there have been several periods during which large areas of the oceans were oxygen-deficient. During these periods this effect could have contributed to long-term removal of carbon dioxide from the atmosphere."

There is a positive "spin" at the end of the presentation of the Medea Hypothesis. I label it spin because I do not think that technology will provide what Ward thinks it will. Too many other scientific publications point to technology being precisely what has CAUSED these predicaments and not something that can solve them AND much of this science is more recent than his presentation is. I am willing to agree that IF society was to suddenly stop consumption and the bad habits of current cultural normality (such as wastefulness and the car culture) and eliminated certain parts of the economy (such as the entertainment and sports industries) and instead incentivized education and microbial and other biological pursuits, perhaps giving nature a chance to thrive, then MAYBE we could reduce some of the hazards of climate change; at least for a while. Ultimately, current teachings would need to focus on ecological overshoot, as that is the primary cause of the climate predicament. However, given the current atmosphere of science education to most people here in the U.S., I would say that such a scenario is unlikely at best.