Lets talk about our Nitrogen Footprint
How do you spend a great wet day indoors in the not so sunny Vancouver, British Columbia? You spend it at UBC attending their One Day @ UBC Centennial Lecture Series. A morning session on Income Inequality followed by one on Climate Change is too hard to pass up, right? Dr. Hadi Dowlatabadi, from UBC, gave a very animated and opinionated talk on “Climate Change in the Global Context”. The talk ended up being different from the usual Climate Change spiel. He argued how climate change is not about humanity going through an existential crisis, as even a six degree change in temperature or the ice caps melting wont put human life in any existential danger. While my concerns with climate change are not around us not being able to exist, but lets save that for another day and focus on things that he did think we should care about.
One of the things he mentioned during his talk was the human impact on nitrogen pollution and how its more pervasive and potentially much worse than Carbon.
Nitrogen Cycle
One may wonder why we care about nitrogen pollution when nearly 80% of atmosphere is nitrogen? Nitrogen is one of the key ingredients necessary for plant growth. However plants cant consume nitrogen gas directly and must have it broken down into reactive nitrogen that can be assimilated by them.
This whole process of cycling atmospheric nitrogen through the soil and vegetation is the heart of the nitrogen cycle. Bacteria breaks down atmospheric nitrogen into reactive nitrogen to be used by the plants. These plants then convert it back to stable nitrogen gas, which is then returned to the atmosphere.
Why are we concerned about Nitrogen?
Nitrogen gas on its own is actually stable, but derivatives from reactive nitrogen like oxides of nitrogen, ammonia etc are a big concern both environmentally and also for human health. When we talk about nitrogen pollution or nitrogen waste we are effectively talking about all nitrogen compounds other than the stable nitrogen gas.
This nitrogen cycle, while indispensable, is slow and hence limits the agricultural output. This changed, when the Haber-Bosch process was invented in the first half of the 20th century to produce ammonia using nitrogen and hydrogen gas. This process of making synthetic fertilizer heralded a new era of food growth that has actually been one of the leading causes of explosive population growth. In fact the use of these is so ubiquitous that its estimated that nearly 80% of nitrogen found in human tissue originated from the Haber-Bosch process and not from natural sources.
However this fertilizer runs off into rivers and streams and has led to an alarmingly elevated level of nitrogen inside lakes and oceans. This run off creates huge dead zones, which as the name implies are bereft of all life thanks to us. For example the Mississippi river flushes a large amount of human, animal, industrial and agricultural nitrogen waste into the Gulf of Mexico, creating one of the biggest dead zones in the world.
In addition to this, nitrogen oxides magnify the green house effect. These gases are 300 times more potent when it comes to global warming than carbon dioxide. But it does not stop there as nitrogen waste leads to ozone depletion in the upper atmosphere and to smog in the lower. Various studies have linked it to several health problems. Nitrogen waste also leads to acid rain and ocean acidification.
This drain of waste into the oceans, coupled with over fishing has led to the nearly 500 dead zones world wide and 70% of all of the worlds fisheries left depleted to the point of collapse. These also have played a pivotal role in rising acidification of the ocean waters and have left scientists wondering how long do we have before a complete collapse of ocean biodiversity?
What’s the biggest cause?
We have completely obliterated the natural nitrogen cycle. While human sources account for less than 5% of total carbon emissions, the number is a staggering 70% for nitrogen. These nitrogen emissions are coming from fuels, animals, agriculture and industries.
Animal agriculture (animals farmed for food and food grown to sustain those animals) accounts for 67% of all human nitrogen emissions. Basically 45% of all of the world’s nitrogen emissions including all of natural ones are caused by animal agriculture.
Dr. Vaclav Smil has spent a lot of time researching on how humans are harvesting the biosphere. While its easy to think that we live in a non agrarian economy, the truth of the matter is that our very existence still relies on us exploiting the biosphere. This was a surprise to even Bill Gates during his conversation with Dr. Smil that our livestock accounted for 98% of all biomass of vertebrates on the entire planet. Yes, all the wild animals in the world combined contribute to 2% of the biomass, while animals grown for consumption accounted for nearly 70% of all biomass. Keeping 70% of our world’s biomass alive and fed for our food is taking a toll on our nitrogen and carbon cycles.
Perpetual Growth Machine
Human meat consumption has gone from a few kilograms an year to over a hundred an year. Our farming is struggling not to provide food for humans, but to our cattle, so that they can be used for food. This is the most inefficient means of growing food. Think of it like this: if you were to eat a hamburger it would be equivalent of making 18 nutritionally equivalent burgers from plants, then throwing them away and then eating the meat one. Perhaps this is why Bill Gates, being an engineer at heart, wants to make this process more efficient?
Dr. Dowlatabadi loved to talk about how using GMO is necessary to meet food demand. This is not true, as we are struggling to meet the demand for meat and not food. We actually have enough capacity to feed 10 billion people already. With meat consumption rapidly rising we are having trouble growing enough feeder crops. This has led to a perverse level of farming, causing the biggest impact in our nitrogen and carbon cycles. In addition to this the waste from animal agriculture has left our lakes and oceans devastated.
This perpetual growth cycle of economics applies to our food and we like to make an industry out of environmental problems. We love to create problems and then talk about how we need more economic growth to invest in solving those problems. For example according to Dr. Dowlatabadi we don’t fertilize our crops enough. Lets take a minute to let the irony sink in given that most of those crops are for animal agriculture, the leading cause of climate change and nitrogen imbalance. This is actually eerily similar to a recent suggestion to manually release suspended particles into upper atmosphere to combat climate change.
Well, technology will fix it…
A lot of the narratives I hear today are either how humans wont be affected by climate change or that the technology will fix it. The first one is more of a threat to existence argument I mentioned at the start. However if that existence comes at the cost of collapse in biodiversity is that a price ok to pay? More often though I hear arguments on how technology is going to fix these problems. For example because of our research in antibiotics (and the fact that 80% of all manufactured antibiotics go towards farm animals) we can magically keep livestock alive and fit enough for consumption, despite their deplorable conditions.
But do we want to solve problems that way? As an engineer we talk about technical debt when it comes to software and I see this as an equivalent environmental debt. Do we really want to generate this environmental debt? At what point do we stop and say that we have so much of this environmental debt that its crippling us, and our actions are governed by past debt?
