Anthropogenic ocean nitrification has dramatically increased chemically neutering the oceans.
We, the human race, seem to be able to assimilate the simplified chemistry of the fossil fuel age by understanding that when we burn fossil fuels (carbon) in air one problematic product of that combustion is CO2. It’s just that simple, right?
Wrong! In fact when one burns fossil fuels in air you must remember that 78% of that air is actually nitrogen. Less than 21% of the air is oxygen. So while the oxygen in air is becoming CO2, what becomes of that nitrogen when it is burned with fossil fuel and where does that stuff go?
Part of the nitrogen burned with fossil fuels becomes nitrogen oxides (NOx) which are emitted into the air along with the carbon oxides as in carbon dioxide. Additional NOx arrives in the ocean from agriculture and industry. Carbon dioxide (CO2) and nitrogen oxides (NOx) both readily dissolve in water which means the fate of these noxious emissions is ultimately to be mixed into the worlds oceans that cover 72% of this blue planet.
Human-induced changes to Earth’s carbon cycle – for example, rising atmospheric carbon dioxide leading to ocean acidification – have been observed and well documented for more than a century. The oceans acidity, its pH, has been shown to have declined by 30% since the start of the fossil fuel age. And these dramatic effects and harm comes from the CO2 we’ve already emitted. An ever more decrease of ocean pH and acidification is certain as we pour more fossil CO2 into the air and oceans.
A new study published recently in the Journal Science showed human activities, in particular industrial and agricultural processes, are definitively shown to have significant impacts on the upper ocean natural nitrogen cycle, ocean nitrification. Nitrates in the surface ocean are now 150% of natural levels as anthropogenic nitrate deposition is shown to be equal to 50% of the of natural nitrate processes. This portends a chemical and ecological impact equal to or even greater than that of CO2. Together the double punch of anthropogenic CO2 and NOx have chemically castrated the wild out of the ocean.
Anthropogenic ocean nitrates are shown to be half as much as natural nitrates in the worlds oceans!
The rate of deposition of reactive nitrogen (nitrogen oxides from fossil fuel burning and ammonia compounds from fertilizer) from the atmosphere to the open ocean has more than doubled globally over the last 100 years. This anthropogenic addition of nitrogen has reached a magnitude comparable to about half of global ocean nitrogen fixation (the natural process by which atmospheric nitrogen gas becomes a useful nutrient). And with ever more fossil fuels being burned ocean nitrification can only get worse unless something is done about this crisis.
The team reporting this dire condition of the North Pacific ocean is led by one of the world’s greatest ocean scientists Dr. Dave Karl, Professor of Oceanography at the University of Hawai‘i at Mānoa. Karl teamed up with researchers from Korea, Switzerland and the U.S. National Oceanic and Atmospheric Administration to assess nearly 50 years of measured changes in nitrate concentration between the 1960s and 2000s across the open North Pacific Ocean.
Dr. Karl’s team performed years of analyses on decades of data, which could readily discern human-derived nitrogen from natural nitrogen fixation. Their work has revealed that the oceanic nitrate concentration has increased alarmingly over the these many decades in surface waters of the North Pacific due largely to the enhanced deposition of nitrogen from the atmosphere.
“This is a sobering result, one that I would not have predicted,” said Karl. “The North Pacific is so vast it is hard to imagine that humans could impact the natural nitrogen cycle.”
The researchers used ocean data in conjunction with a state-of-the-art Earth System Model to reconstruct the history of the oceanic nitrate concentration and to make predictions about the future state of the North Pacific Ocean. Their assessment revealed a consistent picture of increasing nitrate concentrations, the magnitude and pattern of which can only be explained by the observed increase in atmospheric nitrogen deposition.
The dramatic doubling of nitrogen deposition in the North Pacific has stunning potential ecological ramifications. Because biological activity, primary productivity of ocean pastures, is limited by nitrate availability in the North Pacific Ocean, the doubling of new nitrogen from the atmosphere is certain to increase photosynthesis in the sunlit ocean pastures. This is akin to the effect any farmer or rancher would expect to see on pastures on land were they to choose to intensively fertilize those pastures to grow more grass. The dramatic increase in ocean pasture productivity isn’t all bad news as this has the potential to greatly increase photosynthesis and the fixation and export of CO2 out of the surface ocean into the deep.
“The burgeoning human population needs energy and food – unfortunately, nitrogen pollution is an unintended consequence and not even the open ocean is immune from our daily industrial activities,” said Karl.
Given the likelihood that the magnitude of atmospheric nitrogen deposition will continue to increase in the future, the North Pacific Ocean is now switching from a nitrogen poor pasture to one having surplus nitrate. Thus, past and future increases in atmospheric nitrogen deposition have the potential to alter the base of the marine food web and, in the long-term, the structure of the whole ecosystem.
In particular, the shift in nutrient availability could favor marine organisms that thrive under the high nitrate and low phosphorus conditions. Surely the work shown in this magnus opus of ocean science research findings similar trends will be rapidly confirmed in the Atlantic and Indian Oceans. This new lesson in basic fossil fuel chemistry that includes nitrogen shows another example of our global-scale alteration of this blue planets ecology.
Ocean Ecosystems Are Dramatically Changed And No Longer Wild – It Is Up To Us To Care For Our Chemically Domesticated Oceans
This definitive research proves with facts beyond any shadow of doubt that the oceans are no longer a wild natural environment. They are today and likely for millennia to come dramatically chemically changed by our emissions of carbon and nitrogen resulting from the countless billions of tonnes of fossil fuels we have already burned. Let’s call those emissions yesterday’s emissions.
The time it takes for yesterday’s emissions to slowly dissolve into the oceans is measured in centuries not years. So today the observed changes wrought in the oceans is the result of just a fraction of yesterday’s carbon and nitrogen oxides dissolving into the surface ocean. There is a great surplus of yesterday’s emissions in the air and on the way into the oceans. Many are immediately crying out to stop or slow down more emissions by limiting the burning of additional fossil fuels. (Good luck with that.) While this is a necessary notion it does nothing to address the incredible overdose of emissions already in our air and oceans that is destined to continue to change the oceans for more than 100 years to come regardless of whether we were to stop burning all fossil fuels tomorrow.
The first dose of emissions is surely a lethal overdose for ocean life as we know it and something must be done about this first deadly dose.
Fortunately Mother Nature teaches us of the natural antidote to this first deadly dose of emissions now shown to be destroying ocean pastures. At the same time that CO2 and nitrates have been ending up in the oceans their presence is also seen in dramatic global greening of earth. While the earth’s lands becoming more green is good news for the land all that extra grass growing on land is terrible news for the oceans.
More grass growing means less dust blowing.
Yin and Yang of dust and rain
We now know not all seemingly good green news is good news everywhere. Soil conservation along with high and rising CO2 in our atmosphere is growing lots of ground cover the world around. That ground cover is working a miracle on land and preventing vital topsoil and vital mineral dust from blowing in the wind. Read more about human eco-engineering that is turning the dry dusty regions of the world green in this story of The Great Green Wall.
Coincident to the reduction of dust blowing in the wind is a terrible drought of dust which is starving ocean pastures. This drought of vital dust for the ocean is so severe that in each and every five years since we started watching closely beginning in the 1980’s we have seen and measured a terrible loss of ocean plant life, the ocean pastures and their phytoplankton.
To put this in a terrestrial context this loss of ocean plant life is the same biomass gone missing as if we had clear-cut an entire Amazon Rainforest worth of plants on land every five years. Count it up for each five years since 1980, that is more earthly/ocean plant life gone than all the rainforests that have ever existed in human history.
Read more on this Yin and Yang of pastures on land and sea here…
The good news is the antidote is at hand
The ocean pastures are so resilient they will come back to health in a single season with a very little help from us. All they need is a little dust, in the wind… or from our human hands a tiny portion of that same natural dust delivered to replenish that which we are denying the ocean pastures. With vital iron carrying dust to replenished that we have denied the the oceans they bloom in incredible abundance.
Twenty five years and a quarter of a billion dollars in ocean research have proven the antidote is effective. Becoming good shepherds of ocean pastures will cost the tiniest fraction of the money devoted to reducing fossil fuel emissions. Our restored and replenished ocean pastures will consume our fossil fuel emissions converting them into life itself.
In the bargain our lovingly shepherded and renewed ocean pastures will bring back the fish putting a billion additional fish on the plates of hungry people around the world. Read more here at Bring Back The Fish.
Journal reference: Increasing anthropogenic nitrogen in the North Pacific Ocean. Il-Nam Kim, Kitack Lee, Nicolas Gruber, David M. Karl, John L. Bullister, Simon Yang, Tae-Wook Kim. Science, 2014 DOI: 10.1126/science.1258396