The way that humans have messed with the Earth’s carbon cycle rightly figures as planetary eco-problem No.1 in public debate, but the way we’ve messed with its nitrogen cycle probably ought to get more attention than it does. In the former case, farming often gets a bit too much of the blame in my view, whereas in the latter case there’s no doubt that it’s the key culprit. The consequences for nature loss, human health and climate change are serious. If humans somehow manage to get over their fatal attraction to the fossil fuels that drive our messing with the carbon cycle while retaining anything like present patterns of energy use, then our messing with the nitrogen cycle will loom all the larger as a problem of high-energy human civilization. According to the planetary boundary framework, human use of nitrogen (and phosphorus) is already a long way past levels compatible with the stability and resilience of earth systems.
The inimitable Gunnar Rundgren has been writing an excellent series of articles about farming and the nitrogen cycle. I’m not going to cover much of the same ground, but I’d recommend taking a look at his analysis. Instead, I focus more on arguments about … well, arguments about arguments about nitrogen. And an argument about how we might get by with using less of it.
But let me get into that by outlining what seems to me a problematic modern mythology around nitrogen in agriculture that goes something like this: prior to the invention of the Haber-Bosch method for ammonia synthesis, people were miserably yoked to the soil as servants of the natural nitrogen cycle. But once Messrs Haber and Bosch had worked out how to transcend this nature-imposed limit, a world of abundant cheap food opened up for humanity…
…click on the above link to read the rest of the article…
