I have very little direct contact or experience with the world's oceans. For this reason, this page will deal with the differing opinions of scientists involved in this field and my opinions, when expressed, will concentrate on the believability
of their interpretations.
I live in an area where there is no likelihood of any direct effect from changing oceanic conditions, outside of the price of seafood. Perhaps that makes it possible for me to present an unbiased viewpoint but
with the absence of any personal direct observation.
One of the major concerns expressed is that an increase in atmospheric CO2 is increasing the acidity of ocean waters. Apparently, recent years have seen the average pH levels of ocean waters change from about 8.2 to 8.1.
Other sources put ph levels of the seas between
7.9 and 9. Whats up with that.
My first reaction to this is, how do you turn a decrease in alkalinity into acidity.
The second is, how do you measure a difference as small as that over the vast amount of water in the oceans.
There are many variables for which adjustments must be made. Rainfall, freshwater infusions, and industrial activity as well as atmospheric concentrations of CO2, are just some of the localized factors that could affect the ph balance. Data prior
to 1990 is unreliable and later measurements must suffer from a lack of data points considering the vastness of the seas. It seems to be inferred because it is possible, and reinforced by other indirect observations. It seems we may be being asked to simply
accept that ocean pH is dropping.
You may notice that I have been avoiding the use of the word acidity. That is because the oceans are still far from being acidic and only approaching neutrality which would be at a ph of 7.
is a quote from a scientific site, “Their shells and skeletons may dissolve more readily as ocean pH decreases and seawater becomes more corrosive;”. And this one “an increasingly corrosive environment”. If I remember my high school
chemistry correctly, then seawater is becoming less caustic as it becomes less alkaline and comes closer to a ph of 7. Is this a misrepresentation meant to deceive? Is it an outright lie meant to create anxiety amongst us lesser mortals, or can men and women
of science be mistaken on such a basic chemical concept? Read it yourself at this link.
“Ocean acidification is occurring at a rate 30 to100 times faster than at any time during the last several million years driven by the rapid growth rate atmospheric CO2 that is almost unprecedented over geologic history”
from the same article. How is something almost unprecedented. That can only mean that there are precedents, which I suspect there are, but that do not support their premise. There are two things, presented here with a wide range of uncertainty (30 to 100 times),
that we are being asked to accept as truth without any real support. Acidification is occurring ( has occurred, will occur) and that it is driven (apparently exclusively) by atmospheric CO2.
chemistry of how atmospheric CO2 can decrease seawater alkalinity is a little more difficult to understand. My basic understanding is that carbon dioxide mixing with seawater can form carbonic acid (H2CO3), which makes sense.
“When CO2 from the atmosphere reacts with seawater, it immediately forms carbonic acid (H2CO3), which in itself is unstable. This further dissociates to form bicarbonate and carbonate ions. Apparently, it lasts only a fraction of a second. The bicarbonate and carbonate ions are responsible for the buffering capacity of seawater, i.e. seawater can resist drastic pH changes even after
the addition of weak bases and acids. The carbonate ion can react with calcium ions (Ca), which are in excess in seawater, to form calcium carbonate (CaCO3), the material out of which the shells of mussels, the skeleton of corals and the exoskeleton of some
microalgae is made of.” - From Carboschools. Highlighted sentence added by me.
Clear as mud? None of this indicates to me that atmospheric CO2 has a significant effect on the alkalinity of the oceans, or the ability of sea life to build shells.
The next obvious question would be, how damaging can additional CO2 be.
The major concern seems to be the effect on shellfish, microflora and reef-building corals, all of which use
components of seawater to build shells or protective structures. It would seem (from the above) that the CO2 is essentially taken up as calcium carbonate and would make more material available for shell or reef building.This does not mean that all
users would benefit, but many obviously would.
“A new study has yielded surprising findings of how the shells of marine organisms might stand up to an increasingly acidic ocean in the future. Under very high experimental CO2 conditions, the shells
of clams, oysters, and some snails and urchins partially dissolved. But other species seemed as if they would not be harmed, and crustaceans, such as lobsters, crabs, and prawns, appeared to increase their shell-building” from Oceanus Magazine.
Notice the title of the article, that seems to be designed to create
In about 1980, many scientists had decided that human-induced increases in atmospheric CO2 were leading to a catastrophic increase in global temperature. First, it was described as global warming and later as climate
At about the same time, Marine scientists noticed a phenomenon which they named with the descriptive phrase “coral bleaching”.
Although there was little or no previous observation as to the
existence or non-existence of bleaching, it was almost immediately decided that this was not a natural process and must be caused by human activity. It was inevitable that a link would be made to anthropogenic climate change. Sometimes the news seems rather concerning.
Reef-building corals, in forms similar to today, have been around for about 220 million years. They survived the extinction event that wiped out the dinosaurs, about 65 million years ago. They must have evolved through many changes in oceanic
conditions and chemistry. It seems little preposterous
to believe that a small temperature change, or a small lowering of ocean alkalinity, would have a serious effect on them. On the other hand, they could be drowned by sea level rise, or exposed by sea level drop, either of which could cause bleaching. Corals grow at rates considerably faster than current sea level rise.
Toxic effluent from municipalities, industry, and agriculture could have disastrous effects, at least
I have not found enough conclusive evidence being presented to make a decision as to the validity of a link between coral bleaching, atmospheric CO2, and global temperature increases. Links provided may help you to
understand the problem, or decide if a problem exists.
Sea level rise is a consequence, possibly severe, of increasing global temperatures.
Waters could rise, relative to land, as a result of thermal expansion
and of the melting of ice on land. This may be tempered by increased precipitation increasing the water held on land and in the atmosphere. It is even possible that increased precipitation could facilitate the growth of many glaciers. Glaciers grow when more snow is added to them than can melt in the following season.
course, ice (glaciers) has been melting back, at first rapidly then more or less steadily, for about 11,700 years. There is no reason to expect that process to end any time soon. When it does it will signal the beginning of the next ice age but that is not
likely for another 8 to 12 thousand years.
The worry, then, is that anthropogenic induced warming could accelerate the process to the point where we would not have time to adapt and civil chaos would result.
fast will sea levels rise? In the last century, it is thought that seas rose by about 6.7 inches (17cm). Part of that was caused by human pumping of groundwater. "Already, he and his colleagues have found, groundwater depletion is adding about 0.6 millimeters per year (about one-fortieth of an inch) to the Earth's sea level."- From National Geographic. Few really noticed.
Of course, groundwater is limited. It is questionable how much more can be pumped and added to sea levels. It is likely the world will become much more dependent on desalination.
There is no shortage of scare stories and dire predictions making the rounds, but what is more likely? If I were to make a guess, I would say, something close to historical rates, or approximately 6 to 10 inches per century. Of course, if we enter a cooling period for part of the century, as some predict, or we have some major volcanic eruptions, all bets are off. In other words, there are just too many possible variables over the span of centuries
to make reasonable predictions, and there is really no point in worrying about it. Many other things will likely change far more noticeably in the next few centuries.
Beachfront property may not be the best long-term investment, but
if you just want a summer residence for the next few years, take the risk.
On the other hand, here
is a study that shows we are gaining land from the oceans rather than losing it. It is not likely relevant to your beachfront property, but interesting nonetheless.
Another bit of research, really hard to ignore, that shows variable sea levels in the last several hundred years at Goa, India. It indicates that sea levels were nearly 20 inches higher than present
in the 17th century.
"In addition, the Earth’s coasts actually gained land over the past 30 years, according to another study published August 25 in Nature Climate Change.
Researchers led by Gennadii Donchyts from the Deltares Research Institute in the Netherlands
found that the Earth’s surface gained a total of 58,000 square kilometers (22,393 square miles) of land over the past 30 years, including 33,700 sq. km. (13,000 sq. mi.) in coastal areas."
“We expected that the coast would start to retreat
due to sea level rise, but the most surprising thing is that the coasts are growing all over the world,” study co-author Fedor Baart told the BBC.
“We were able to create more land than sea level rising was
The waters of our planet may not be at great risk from CO2, or a warming environment, but there is no arguing that they have been severely damaged by careless human usage. It is essential that we stop using
rivers and seas as dumping grounds for our waste. Raw sewage and industrial effluent is extremely
damaging when dumped into the waters of the world. Agricultural runoff, including pesticides, fertilizers, and animal waste is profoundly altering the chemistry of both fresh and seawater, and killing or endangering sea life. Overfishing is badly depleting
our commercial fisheries. Solid waste has accumulated to astonishing levels in some
areas of the oceans and in our freshwater sources.
is way past the time that we quit worrying about possible outcomes from possible scenarios and actively aided in the recovery of our waters.