Global Ocean Destruction :Can we stop ourselves destroying our own life support systems? - The Comprehensive Minds

Global Ocean Destruction :Can we stop ourselves destroying our own life support systems?

 Global Ocean Destruction

Global Ocean Destruction

About the middle of September each year, as the northern hemisphere summer season draws to a close, the Arctic Sea reaches a point of minimum sea ice cover. 

As many of you no doubt already know, the extent of that annual minimum has been declining ever since satellite records began back in the late 1970s, and in 2012 the region experienced a record low extent of 3.41 million square kilometers, leading some commentators to suggest we might see an ice-free summer arctic by 2020.


arctic sea ice intact

Thankfully that didn't happen and in fact, the annual minimums have fluctuated a little bit since then. This year's minimum was actually only the 12th lowest on record although it was still well below the level seen in the 1980s. 

There were some quite well documented and fairly regional specific weather events causing this year's somewhat unusually high minimum which are unlikely to combine together in the same way next year so the trajectory of travel is quite likely to continue inexorably towards zero over the coming years.   

Our sea and oceans cover 71 percent of the earth's surface and they're responsible for regulating our planet's climate and sustaining all life. They've already absorbed about a third of all the carbon dioxide we've emitted since the industrial revolution and about 90 percent of the earth's extra heat since the mid-20th century. 

Our human activity and over-exploitation of ocean resources are turbocharging natural variation causing unprecedented changes in the composition of the water itself, the ecosystems within it, and the coastlines that surround it. 

In September 2021 the Copernicus Marine Service published the latest of their annual reports using a set of parameters called ocean monitoring indicators to describe measure and monitor the state of the ocean,   observing all the relevant phenomena causing the changes. 

Those phenomena are grouped into three categories, the first of which they call the Blue Ocean describing the physical state of the ocean including things like sea surface temperature, sea level, ocean currents, waves, and sea winds as well as ocean heat content, salinity, and density. 

This year's analysis shows that sea surface temperatures in all parts of the global oceans increase by an average of 0.01 degrees Celsius every year between 1993 and 2019. 

That might not sound like a lot on an annual basis but it adds up to an increase of 0.4 degrees Celsius over just 26 years, with the surface of the Baltic and Mediterranean warming by almost a full degree Celsius over that time period. Global sea levels have been rising by just over three millimeters per year or about eight centimeters since 1993 and the rate of rising is accelerating. 

Again the Baltic Sea has seen the biggest rise at almost 12 centimeters. The overall heat content of the oceans is measured in watts per square meter just in the same way that we measure the energy from sunlight hitting our planet each day.   

To maintain stable planetary systems there should be more or less no increase in land or sea surface temperature, in other words, the heat energy reaching our planet should be balanced by the heat energy escaping our planet each day. That's pretty much the way things were from the end of the last glacial period about 10 000 years ago right up to the beginning of the industrial revolution.   

There are some small variations in the solar irradiance reaching us as a result of orbital fluctuations in solar activity. 

Also Read: Human-made objects already weigh more than all the biomass on Earth

People much smarter than me have calculated the range of those changes as being between 0.05 and 0.15 watts per square meter but this analysis shows that just in the 14 years between 2005 and 2019 the heat content of the oceans from the surface right down to a depth of 2000 meters has increased by one watt per square meter, which across an expanse of water as vast as that is an absolutely mind-blowing amount of energy.   

Why is all that important? 

Well, the report explains that sea surface temperature plays a vital role in regulating the earth's climate and atmosphere and in influencing the evolution of severe weather events. Ocean warming contributes about 30 to 40 percent to global means sea level rises worsening the already catastrophic flooding happening in low-lying areas, damaging coastal infrastructure, and disrupting coastal marine environments.   

Warmer waters alter ocean currents and reduce the solubility of carbon dioxide in the water which means more CO2 stays in the atmosphere instead. The extra heat also causes stratification or temperature layering at different depths making it much more difficult for nutrients to rise up from the deep waters to feed phytoplankton and other fundamental elements in the ocean's food chain, which brings us to the second ocean monitoring indicator - The Green Ocean. 

This one refers to the biological and biochemical state of the ocean including chlorophyll and nutrient concentrations as well as ocean acidification and deoxygenation.  Essentially the ecosystems in the oceans are extremely sensitive to quite small changes in pH levels of the water. Between 1985 and 2019 average pH levels have reduced by 0.06 units. 

acidification and deoxygenation

Again that sounds tiny as a number but on the pH scale, it represents a 30% increase in acidity posing a  severe threat to marine life and especially to corals and shellfish that increasingly struggle to find the calcium carbonate that they need for their structures. 

ocean eutrophication

Roughly half of the earth's oxygen production also takes place in the oceans. As we humans continue to accelerate climate change and release excessive nutrients into the water from agricultural and chemical runoff, a process known as eutrophication, we're contributing to dangerous levels of deoxygenation threatening marine life cycles all the way from the seashore right down to the greatest ocean depths. 

Then there's The White Ocean, which as the name suggests refers to the life cycle of floating ice within the polar regions. The study shows that between 1979 and 2020 the annual average extent of sea ice in   The Arctic has been reducing by more than half a million square kilometers per decade with an even more dramatic decrease of more than eight hundred thousand square kilometers per decade in the summer months. 

The White Ocean

A reduction of nearly 13% every 10 years. And you don't need to be Einstein to work out how that's going to end, as this graphic representation by Andy Lee Robinson shows all too clearly. Check out the black line representing the annual September minimum. As it winds around the dial from 1979 through to 2021 you can see how it's spiraling in towards zero or what some climate commentators refer to as a blue ocean event. 

The consequences of that eventuality are very severe indeed not just for marine life but for almost every aspect of human existence on the planet. And in case you were hoping that the losses in the arctic might be compensated by gains in the Antarctic well no such luck I'm afraid.   

There has been a slight increase in the Antarctic sea ice extent but according to this report, it's really not enough to be statistically relevant. The impacts of a changing ocean are now being felt in just about every corner of the planet. 

Rising sea levels have already engulfed some parts of the small island nations forcing communities to continuously move from island to island or try to find a way to relocate to a mainland - something that's much easier said than done.   

Low-lying coastal regions of Bangladesh

Low-lying coastal regions like those in Bangladesh will be overwhelmed in the coming years causing mass migrations of very large populations of people, and the rich western nations won't escape the consequences either. 

Venice was a high-profile example in 2019 when a combination of unusually high sea levels a high spring tide and extreme local and regional weather conditions caused an unprecedented series of exceptionally strong high waters or aqua Alta events as the locals call them. 

Water levels rose by 1.89 meters which is more than six feet - the highest recorded level since 1966. Warming ocean waters have also caused many marine species to move towards cooler waters either going deeper in the ocean or physically migrating towards the poles.   

Also Read: Whales are returning to the poles for the first time in 40 years

Those migrations are not only depriving regional fishermen of the fish stocks that they and their families rely on but they're also resulting in the introduction of non-native and invasive species to different marine ecosystems. 

In 2019 increasing temperatures in the eastern Mediterranean basin resulted in an infiltration of the highly predatory lionfish into the Mediterranean sea from the Suez Canal to the Ionian sea decimating local marine life that had no defenses against this alien invader. 

And extreme temperature events like marine heatwaves are becoming more common more severe and longer-lasting affecting the catches and populations of various marine species.   

So what can we do in the face of these mountain catastrophes?   

global structure of monitoring

Well in conjunction with all these other agencies and organizations the Copernicus Marine Service is advocating a global structure of monitoring, communication, education, and governance aimed at shifting human interaction with the oceans towards much more intelligent and sustainable stewardship as the consequences of climate change continue to worsen.   

Observations like those carried out by Copernicus are showing that the oceans have been absorbing so much of the CO2 and heat energy that we humans have spewed out over the last couple of centuries that they've really been masking the true severity of our climate predicament.   

That can't continue indefinitely of course and there are already signs that the oceans are reaching the limits of what they can cope with, so initiatives like the Copernicus program will play a vital role in raising awareness and urgency in the minds of our world leaders. Let's hope they find the wisdom to listen and act.

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