Thongchai Thailand

FOSSIL FUEL EMISSIONS DISSOLVING THE SEA FLOOR

Posted on: January 22, 2020

 

THIS POST IS A CRITICAL EVALUATION OF THE CLAIM THAT AGW CLIMATE CHANGE IS DISSOLVING THE SEA FLOOR. IT IS PRESENTED BELOW IN TWO PARTS. THE CLAIMS MADE BY CLIMATE SCIENCE ARE PRESENTED IN PART-1. THEIR CRITICAL EVALUATION FOLLOWS IN PART-2  

 

PART-1: REPORTS THAT OCEAN ACIDIFICATION BY AGW CLIMATE CHANGE IS DISSOLVING THE SEA FLOOR. 

  1. SOURCE: PRINCETON UNIVERSITY. DATE: NOVEMBER 2018 [LINK] : With increasing carbon dioxide from human activities, more acidic water is reaching the deep sea and dissolving some calcite-based sediments. The seafloor has always played a crucial role in controlling the degree of ocean acidification. When a burst of acidic water from a natural source such as a volcanic eruption reaches the ocean floor, it dissolves some of the strongly alkaline calcite like pouring cola over an antacid tablet. This neutralizes the acidity of the incoming waters and in the process, prevents seawater from from becoming too acidic. It can also help regulate atmospheric carbon dioxide levels over centuries to millennia. As a result of human activities, the level of carbon dioxide in the water is high enough that the rate of calcite (CaCO3) dissolution is climbing. These findings appear this week in the journal Proceedings of the National Academy of Sciences. Calcite-based sediments are typically chalky white and largely composed of plankton and other sea creatures. But as the amount of carbon dioxide (CO2) and other pollutants has climbed over recent decades, more and more acidic water is reaching the seafloor, at least in certain hotspots such as the North Atlantic and the Southern Ocean, where the chalky seafloor is already becoming more of a murky brown. For decades we have been monitoring the increasing levels of anthropogenic carbon dioxide as it moves from the atmosphere into the abyssal ocean. While expected, it is none the less remarkable that we can now document a direct influence of that process on carbonate sediments. Because carbon dioxide takes decades or centuries to travel from the ocean surface to the seafloor, the vast majority of the greenhouse gas created through human activity is still near to surface. The rate at which CO2 is currently being emitted into the atmosphere is exceptionally high in Earth’s history, faster than at any period since at least the extinction of the dinosaurs, and at a much faster rate than the natural mechanisms in the ocean can deal with, so it raises worries about the levels of ocean acidification in future. It is critical for scientists to develop accurate estimates of how marine ecosystems will be affected, over the long term by the human caused acidification. Researchers created a set of seafloor-like microenvironments in the laboratory, reproducing abyssal bottom currents, temperatures, chemistry and sediment compositions. These experiments helped them to understand what controls the dissolution of calcite in marine sediments and allowed them to quantify its dissolution rate as a function of various environmental variables. By comparing pre-industrial and modern seafloor dissolution rates in this laboratory model of the sea floor, they were able to extract the human-caused fraction of the total dissolution rates. The speed estimates for ocean-bottom currents came from a high-resolution ocean model. Just as climate change isn’t just about polar bears, ocean acidification isn’t just about coral reefs. Our study shows that the effects of human activities have become evident all the way down to the seafloor in many regions, and the resulting increased acidification in these regions may impact our ability to understand Earth’s climate history.”“This study shows that human activities are dissolving the geological record at the bottom of the ocean.
  2. SOURCE: SMITHSONIAN MAGAZINE. DATE: NOVEMBER 2018[LINK] Parts of the Ocean Floor Are Disintegrating and It’s Our Fault. Calcium Carbonate on the sea floor is dissolving due to the excess carbon dioxide from fossil fuel emissions. Ocean acidification is a worrying by-product of excess carbon dioxide in the atmosphere. It is “climate change’s equally evil twin“. Drops in ocean pH are believed to be having a devastating effect on marine life, eroding corals, making it difficult for certain critters to build their shells and threatening the survival of zooplankton. The effect of acidification extends all the way to the bottom of the ocean, where parts of the sea floor may be dissolving. For millennia, the ocean has had a nifty way of both absorbing excess carbon in the atmosphere and regulating its pH. The bottom of the sea is lined with calcium carbonate, which comes from the shells of zooplankton that have died and sunk to the ocean floor. When carbon dioxide from the atmosphere is absorbed into the ocean, it makes the water more acidic, but a reaction with calcium carbonate neutralizes the carbon and produces bicarbonate. The ocean, in other words, can absorb carbon without “throwing [its] chemistry wildly out of whack. In recent decades, however, the large amount of carbon dioxide being pumped into the atmosphere has upset the balance of this finely-tuned system. Since the beginning of the industrial era, the ocean has absorbed some 525 billion tons of carbon dioxide and calcium carbonate on the seafloor is dissolving too quickly in an effort to keep up. As a result, parts of the seafloor are disintegrating. When it comes to most parts of the ocean floor, the pre- and post-Industrial dissolution rates are actually not dramatically different. But there are several “hotspots” where the ocean floor is dissolving at an alarming rate. Chief among such “hotspots” is the Northwest Atlantic, where between 40 and 100 percent of the seafloor has been dissolved “at its most intense locations. In these areas, the calcite compensation depth,” or the layer of the ocean that does not have any calcium carbonate, has risen more than 980 feet. The northwest Atlantic is particularly affected because ocean currents usher large amounts of carbon dioxide there. But smaller hotspots were also found in the Indian Ocean and the Southern Atlantic. The ocean is doing its job just trying to clean up the mess, but it’s doing it very slowly and we are emitting CO2 very fast, way faster than anything we’ve seen since at least the end of the dinosaurs. Ocean acidification is threatening corals and hard-shelled marine creatures, like mussels and oysters, but scientists still don’t know how it will affect the many other species that make their home at the bottom of the sea. If past acidification events are any indication, the outlook is not very good. Some 252 million years ago, huge volcanic eruptions shot massive amounts of carbon dioxide into the air, causing the rapid acidification of the world’s oceans. More than 90 percent of marine life went extinct during that time. Some scientists refer to the current geologic period as the “Anthropocene,” a term that refers to the overwhelming impact modern-day humans are having on the environment. The burn-down of seafloor sediments once rich in carbonate will forever change the geologic record. The deep sea environment has entered the Anthropocene.
  3. SOURCE: LIVE SCIENCE. DATE: NOVEMBER 2018 [LINK] :  Our carbon emissions are dissolving the seafloor, especially in the Northern Atlantic Ocean. Climate change reaches all the way to the bottom of the sea. The same greenhouse gas emissions that are causing the planet’s climate to change are also causing the seafloor to dissolve. And new research has found the ocean bottom is melting away faster in some places than others. The ocean is what’s known as a carbon sink: It absorbs carbon from the atmosphere. And that carbon acidifies the water. In the deep ocean, where the pressure is high, this acidified seawater reacts with calcium carbonate that comes from dead shelled creatures. The reaction neutralizes the carbon, creating bicarbonate. Over the millennia, this reaction has been a handy way to store carbon without throwing the ocean’s chemistry wildly out of whack. But as humans have burned fossil fuels, more and more carbon has ended up in the ocean. In fact, according to NASA, about 48 percent of the excess carbon humans have pumped into the atmosphere has been locked away in the oceans.
    All that carbon means more acidic oceans, which means faster dissolution of calcium carbonate on the seafloor. To find out how quickly humanity is burning through the ocean floor’s calcium carbonate supply, researchers led by Princeton University atmospheric and ocean scientist Robert Key estimated the likely dissolution rate around the world, using water current data, measurements of calcium carbonate in seafloor sediments and other key metrics like ocean salinity and temperature. They compared the rate with that before the industrial revolution. The good news is that most areas of the oceans didn’t yet show a dramatic difference in the rate of calcium carbonate dissolution prior to and after the industrial revolution. However, there are multiple hotspots where human-made carbon emissions are making a big difference and those regions may be the canaries in the coal mine. The biggest hotspot was the western North Atlantic, where anthropogenic carbon is responsible for between 40 and 100 percent of dissolving calcium carbonate. There were other small hotspots, in the Indian Ocean and in the Southern Atlantic, where generous carbon deposits and fast bottom currents speed the rate of dissolution. The western North Atlantic is where the ocean layer without calcium carbonate has risen 980 feet (300 meters). This depth, called the calcite compensation depth, occurs where the rain of calcium carbonate from dead animals is essentially canceled out by ocean acidity. Below this line, there is no accumulation of calcium carbonate. The rise in depth indicates that now that there is more carbon in the ocean, dissolution reactions are happening more rapidly and at shallower depths. This line has moved up and down throughout millennia with natural variations in the Earth’s atmospheric makeup. Scientists don’t yet know what this alteration in the deep sea will mean for the creatures that live there but future geologists will be able to see man-made climate change in the rocks eventually formed by today’s seafloor. Some current researchers have already dubbed this era the Anthropocene, defining it as the point at which human activities began to dominate the environment. Chemical burn-down of previously deposited carbonate-rich sediments has already begun and will intensify and spread over vast areas of the seafloor during the next decades and centuries, thus altering the geological record of the deep sea. The deep-sea benthic environment, which covers ~60 percent of our planet, has indeed entered the Anthropocene.\

 

 

PART-2: CRITICAL COMMENTARY ON THESE CLAIMS

  1. Since 1751, the Industrial Economy of humans has emitted 1,570 Gigatonnes of CO2. This number can be expressed as 1.57E12 tonnes. We have 1.29E18 tonnes of water in our oceans. In the unlikely and impossible event that all of these CO2 emissions of the Industrial Economy ended up in the ocean, the CO2 concentration of the ocean would rise by the insignificant amount of 1.21 ppm. However, according to the IPCC, most of the CO2 emissions of the Industrial Economy go to the atmosphere and to photosynthesis with approximately net 20% of the emissions going into the ocean. In that case, the increase in oceanic CO2 concentration since 1751 is about 0.242 ppm.
  2. The pH of sea water lies somewhere in the alkaline range of 7.5 to 8.5 with measurement errors of +/- 0.14. Within this uncertainty rate, a measurable perturbation of oceanic pH with fossil fuel emissions is not possible given the relatively insignificant amount of CO2 involved. It is therefore necessary to consider other sources of CO2 that may cause ocean acidification, as for example in the geology of the sea floor where most of the planet’s geological activity takes place.
  3. An example of ocean acidification in the paleo record is seen in the PETM event that occurred about 50 million years ago [LINK] when intense geological activity of the sea floor caused a massive oxidation event in the ocean that at once consumed all the ocean’s oxygen and increased atmospheric CO2 concentration by 70% from 250ppm to 430ppm within an uncertainty margin of +/- 100 ppm. It was not a case where the atmosphere drives changes in the ocean due to the greenhouse effect of CO2 but a case where the ocean drives changes in the atmosphere due to geological forces and geological carbon in the ocean floor.
  4. Incidentally, the PETM caused a significant mass extinction event in the ocean where many species went extinct but also where many new species were created. One of the new species created by this mass extinction event was the modern land-based mammal from which we are derived. The climate change driven ecological view that humans must manage nature such that mass extinctions must not be allowed to happen is inconsistent with the role of mass extinctions and their species explosions in nature’s evolutionary dynamics.
  5. Farther back in time, about 200 million years ago, the paleo data show a horrific geological sea floor cataclysm and ocean acidification that caused one of the largest mass extinction events in the paleo record [LINK] . Dr Willis Hames, Professor of Geosciences, Auburn University writes about this event as follows “A singular event in Earth’s history occurred roughly 200 million years ago, as rifting of the largest and most recent supercontinent was joined by basaltic volcanism that formed the most extensive large igneous province (LIP) known. A profound and widespread mass extinction of terrestrial and marine genera occurred at about the same time, suggesting a causal link between the biological transitions of the Triassic-Jurassic boundary and massive volcanism. A series of stratigraphic, geochronologic, petrologic, tectonic, and geophysical studies have led to the identification of the dispersed remnants of this Central Atlantic Magmatic Province (CAMP) on the rifted margins of four continents. Current discoveries are generally interpreted to indicate that CAMP magmatism occurred in a relative and absolute interval of geologic time that was brief, and point to mechanisms of origin and global environmental effects. Because many of these discoveries have occurred within the past several years, in this monograph we summarize new observations and provide an up-to-date review of the province. {Hames, Willis, et al. “The Central Atlantic magmatic province: Insights from fragments of Pangea.” Washington DC American Geophysical Union Geophysical Monograph Series 136, 2003}.
  6. Here, as in the PETM, and quite unlike the AGW climate change model of ocean acidification, the source of the carbon is the sea floor itself or perhaps even underneath the sea floor in the mantle. Such geological horrors of the planet should serve as a gentle reminder that we are carbon lifeforms that evolved in a carbon planet and that our minute and insignificant ability to put carbon in the atmosphere cannot be assumed to be the driving force that determines the acidity or the fate of the sea floor
  7. An additional consideration is that the dissolving of the sea floor by fossil fuel emissions is described as localized such that they are found only in certain peculiar areas that are described as “hotspots“. Such localization of the effect does not suggest a uniform global cause in the form of atmospheric CO2. Rather it points to the sea floor hotspot locations themselves as the cause in the form of geological carbon hotspots.
  8. Yet another issue is that most of the sea floor consists of large igneous provinces as described by Professor Willis Hames. These ocean floors consist of rocks that are mostly basalt. Basalt is a high pH basic substance and its prevalence on the sea floor ensures that whatever insignificant amount of carbon based acid that humans can produce will be readily neutralized by the basalt on the sea floor. 
  9. It appears that humans have grossly over-estimated their role at the planetary level such that it is popularly assumed that the fate of the planet will be determined by humans. Consider in this respect that the crust of the earth consisting of land and ocean on which we live and from which we draw our planetary relevance is 0.3% of the planet and most of that is ocean limiting the direct experience of us land creatures to less than 0.1% of the planet. Most of the rest of the planet is at and below the sea floor. It is neither necessary nor possible for us to be the managers of the planet such that we must or that we can fine tune the pH of the deep ocean and the sea floor. 

 

4 Responses to "FOSSIL FUEL EMISSIONS DISSOLVING THE SEA FLOOR"

“ the vast majority of the greenhouse gas created through human activity is still near to surface.”

This contradicts the vertical dissolved CO2 profile of the ocean presented in a previous post.

I’m wondering if the “hot spots” are locations where warm ocean currents on the surface cool and sink. That might explain the northwest Atlantic.

Interesting observations. Thank you. I will look into these things

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