Disruption of Global Nitrogen Cycle Exceeds Scale of Climate Change and Ocean Acidification
Few understands the HUGE DISRUPTION to earth's nitrogen cycle that synthetic fertilizer use has caused, that have been known to scientists for at least two decades (that I'm aware of).
No doubt the chemical companies, and the agribusiness giants, played a role in this NOT being widely known, to keep their profits rolling. But the nitrogen cycle is so complex (even more than the carbon cycle), which surely didn’t help getting more people to understand our role in it.
The one consequence I fear the most is discussed following these article excerpts:
Global Nitrogen: Cycling out of Control
'“Humans are changing the nitrogen cycle globally faster than any other major biogeochemical cycle—it’s just going through the roof in a hurry,”'
'“If you put a molecule of NOx in the atmosphere from fossil fuel combustion or a molecule of ammonium on an agricultural field as a fertilizer,” he explains, “you have a whole series, or cascade, of effects that goes from acid rain to particle formation in the atmosphere, decreasing visibility and causing impacts on human health, acid rain, soil and stream acidification, coastal eutrophication, decreasing biodiversity, human health issues in groundwater, and nitrous oxide [N2O] emissions to the atmosphere, which impact the greenhouse effect and stratospheric ozone.”'
'As with water and air, reactive nitrogen builds up in soil. There’s a limit, however, to how much nitrogen plants can use. When soil reaches a point at which plants can’t use additional nitrogen, it’s said to be “saturated.” And saturated soil, in theory at least, will shed any additional nitrogen introduced to it. But that nitrogen doesn’t leave unaccompanied. “When it leaches out of the system,” says Townsend, “it takes other nutrients with it, so it ends up acidifying the soil, and it takes things like magnesium and calcium out into the water. And you end up with a very unbalanced system.”' (potassium too)
We need to talk about nitrogen
'Speaking at the discussion meeting, Jan Willem Erisman from the Energy Research Center of the Netherlands at Petten warned that the human impact on the global nitrogen cycle has already exceeded the limit of the planet's capacity by a factor of four, based on the assessment of Johan Rockström et al. (Nature (2009), 461, 472–475). ...... Compared to other global problems, the effect is comparable to biodiversity loss and exceeds the scale of climate change and ocean acidification, which are also affected by nitrogen imbalances.'
'Denitrification in the oceans is strongly regulated by oxygen concentrations and also intertwined with the cycling of other elements, including carbon and phosphorus, implying that human alterations of the nitrogen cycling has major consequences for other biogeochemical processes and ecosystem functions and services, Voss says.'
Unprecedented levels of nitrogen could pose danger to Earth’s environment
Human Alteration of the Global Nitrogen Cycle: Causes and Consequences
Personally one of the most frightening consequences of an overload of reactive nitrogen making their way from land and rivers into the oceans, is that of eutrophication, leading to algal blooms (including toxic ones), then hypoxia. With worsening eutrophication and the warming of the oceans, each year the ocean anoxic (dead) zones keep expanding, pushing us one step closer to a sudden state shift one day, towards anoxic oceans where only anaerobic bacteria thrives, giving off toxic gases that would then kill off all the rest of life.
oxygen loss is 'emptying vast regions of the ocean......'
'"It's almost like the oceans are getting ready for a heart attack," said Baker. "You're essentially slowing the heartbeat of the ocean, and you're getting less oxygen to the ocean."'
'... the 1980s regime shift represented a major change in the Earth's biophysical systems from the upper atmosphere to the depths of the ocean and from the Arctic to the Antarctic'
'No fish. No birds. Hardly a sign of life at all.'