While listing various environmental issues of how planetary boundaries are exceeded the Stockholm Resilience Centre lists climate change in the "increasing risk category" while listing "Nitrogen and phosphorus flows to the biosphere and oceans" in the high risk category which suggests that they consider it a more grave environmental issue.

Do I misread them? Otherwise, are there views inline with other scientists in their field?

If that's a consensus view, view do we have so much more debate about climate change but none about nitrogen and phosphorus flows?

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I thought this was an interesting question... although I definitely get the feeling like I'm missing some of the context behind this "planetary boundaries" write-up.

(What is the Stockholm Resilience Center? What are its motives and methods? Why was it doing this analysis, and how did you end up running into it?)

I agree that fertilizer runoff gets talked about a lot less than climate change, and I'm not entirely sure of why that is. I just looked it up, and "Organic"-labeled things apparently do already mandate organic fertilizers (which should be N-neutral on net?). So there's at least that.

Regarding their assessment... one of the factors that seemed to be weighted a lot in their assessment was "level of antropogenic change vs natural variation in Process X." I'd expect that to have heavily-weighted the Nitrogen Cycle, since our interference in it dwarves the variability due to natural processes (something they themselves spell out. The Haber process is a strange, powerful, magical, inorganic thing the humans cooked up).

This metric is... not precisely the same as "level of damage this change can cause." They seem to have set up some sort of threshold for what they consider "dangerously high", and I don't really understand the thought-process or reasoning they used in picking those thresholds. But I think they factored "change vs natural variation" into their thinking a good deal.

My understanding from my own Ag background is that fertilizer runoff really can be a big problem; nitrogen and phosphorus are a major limiting nutrient for plant-life, both on land and in freshwater ecosystems (the ocean surface is iron-limited, interestingly). In a sense, this is exactly why we use it; we want our food crops to grow at a wild rate, one rarely seen in nature.

When there's a sudden influx of nitrogen into a freshwater system, one of the possible consequences is an algal bloom. These go through a boom-and-bust cycle (with the seasons, or resource-availability patterns), leading to a massive algal die-off. During this die-off, decay bacteria wipe out the underwater oxygen-supply, leading to knock-on effects on freshwater ecosystems like massive fish die-offs. Enclosed spaces like lakes are perhaps especially vulnerable, since there is no way for the N and P to ever exit the system, potentially perpetuating the cycle indefinitely.

That said, suddenly cutting fertilizer usage would practically ensure that food production would suddenly drop way down, and that would ill-serve a lot of other human values. Reducing runoff looks like a very hard problem, to me. Finding ways to remove excess P and N from environment seemed to be an area with at least a little bit of interest, but it doesn't seem very actionable on an individual rather than city or state level, which might explain the low publicity? Unsure.

There are even weirder systemic effects that happen.

There has been a longstanding, drastic decline in seabird numbers, along with a decline in the upper trophic levels in the ocean, for the last fifty years or so. A few years back, it was determined that at least in the case of seabirds, the limiting factor for their populations appeared to be B-vitamin deficiency of all things - large numbers of birds were dying of it. What could be suddenly causing that was a mystery, with all sorts of dire ideas thrown about regarding collapses in ocean productivity or zooplankton populations.

Turns out that the most likely reason for it is actually nitrogen fertilizer pollution. The algae that bloom in the ocean dead zones where fertilizer runoff hits it turn out to be largely B-vitamin auxotrophs - they cannot make it and take it up from the local ecosystem. And then when the algae bloom dies and the water goes anoxic, they sink to the ocean floor and are buried with the B vitamins they took up, efficiently sucking it out of the ecosystem and burying it in the seafloor.

These systems react in strange, nonlinear ways...

I read quite a while ago originally about the planetary boundaries idea maybe through the TED talk. I got the page of the Stockholm Resilience Center because it's the top Google hit for "planetary boundaries".

I just looked it up, and "Organic"-labeled things apparently do already mandate organic fertilizers (which should be N-neutral on net?). So there's at least that.

That makes it even more perplexing. Why doesn't some organic food company have a budget to push the meme into public consciousness?

But when the argument for the alternative boils down to "eat shit, not chemicals"... I'm kidding, but only slightly. Organic fertilization is a bit gross, and I think most food companies would prefer to not be associated with any of dead leaf matter, rotting leftovers, or manure. Counterargument: Composting totally became a thing, and that potentially puts the grossness right in your backyard. (Huh. Composting is certainly something people do on an individual level to micro-combat the usage of nitrogen fertilizers, with probably a very negligible effect. And some people do seem dedicated to it. But I suspect that if you asked most people who do it, they would claim it's about landfills or something, not soil nitrogen content.)