“Is it the biggest looming crisis that you have never heard of?”, asks this BBC article - running out of phosphates, essential for agriculture. Fortunately we’ve about 67 billion tonnes of the stuff - so we’re in no danger of running out any time soon. Not to mention, we waste a lot of it, so we could cut down on usage when we start to notice a pinch, and we could reclaim some of it.
But sooner or later the reserves will dwindle and we’ll be up shit creek. Possibly in a literal sense, as phosphates from human poop could be used to grow our crops. What will the world do to cope with the shortage? Are there any feasible replacements?
Yeah, the big problem is that we use our current sources very inefficiently. We strip mine phosphate minerals, apply them to crops in tremendous quantities, but most just run off into streams and rivers. A small fraction of phosphate fertilizers are taken up by plants. Of that fraction, some ends up in humans and animals… and a lot passes through. Only a tiny fraction of the original phosphate input is recycled through compost, manure, or sewage sludge fertilizer.
Better agricultural practices result in less runoff – smaller amounts of phosphate are applied to the field, and a greater fraction is taken up by plants. Better recycling of plant, animal and human wastes would recycle more phosphate. Problem is, this is a lot harder and more expensive than current standard agricultural practices.
My WAG is that this problem will solve itself. When phosphate reserves start to run low, mined phosphate will be expensive, and it’ll become economical to waste less and recycle more of it. On the other hand, it’ll mean higher food prices.
Nice article, except that the author makes (but doesn’t state) the idiotic assumption that phosphate consumption isn’t growing. A mistake like that makes me question the whole article.
Remember that you can always harvest phosphate from urine. If it becomes scarce, mankind will be forced to recycle urine for the posphate, rather than polluting the waterways and oceans with it.
This doesn’t appear to be a concern for a very long time to come - probably hundreds of years. The article linked to in the OP even acknowledges this:
Of course the Forbes article you linked to concludes that as well. Yeah, that author doesn’t account for growing demand as Learjeff points out. But his more important point is regarding the difference between proven mineral reserves and mineral resources. And the USGS data he linked to supports his claim that any phosphate shortage is in the distant future.
If there’s a looming phosphate crisis, it’s more likely to be related to this. As worldwide demand increases, the environmental harm due to the way we currently use phosphates seems to be more of an issue than how long it is until that resource becomes scarce.
And that’s my professional opinion, having read a whopping two entire articles on the subject. : )
We need to change farming techniques anyway as the freshwater supply for irrigation is being depleted in many agricultural areas around the world so we will over the next 50 years probably go to drip irrigation to conserve water and fertilizers including phosphates.
Yep. Long before we have to worry about phosphates we’re going to run into some other pretty severe limits, notably a shortage of fossil water from aquifers. When we have to rely on our annual rainfall budget for irrigation water then we’re going to have to be a lot more careful with every drop, which means we aren’t going to be dumping tons of water on fields and watching it run off into the oceans, carrying all the NPK with it.
But of course, people don’t conserve things that are in unlimited supply, even if the supply actually isn’t unlimited. Farmers aren’t going to stop dumping phosphorus on their fields just because farmers 100 years from now might have less phosphorus available. It’s abundant and cheap today and for the foreseeable future, so people are going to use it as if it is abundant and cheap.