The latest concern seems to be that people liking to eat avocados calls forth those who grow avocados:
Mexican farmers can make much higher profits growing avocados than from most other crops and so are thinning out pine forests to plant young avocado trees.
Well, yes, that is how these things work. More people consume something, price rises, people work out how to supply more of that now more expensive thing. And this new production will undoubtedly displace the production of something else.
We cannot find it in ourselves to complain about poor Mexicans becoming richer by feeding a hipster habit.
But there's worse to this thinking:
You might think, OK, I’ll buy avocados from some other less problematic source then. But would an avocado from Chile, Peru or the Dominican Republic automatically be more sustainable or equitably produced? The fact of the matter is that we know pitifully little about the environmental and working conditions of faceless people in faraway places who grow fruit for our tables, but I have seen enough of foreign fruit “farms” to suspect the worst.
At which point we have to point out that that is rather the point. That's exactly the function that markets perform for us. As Leonard Read didn't quite point out, no one at all knows how to produce an avocado.
There is no other system possible to coordinate the activities of 7 billion people than that network of prices and markets. There absolutely is no other system at all to connect more bearded wonders drinking avocado smoothies in London with farmers on some hillsides in Mexico. There is no system of government, of central direction, which could manage this.
All of which means that if you want to consume only those things which can be monitored in such a manner then you're going to have to accept the consumption of only those things which can be monitored in such a manner:
The popularity of kale, for instance, makes all-round sense. It’s democratically cheap, its nutritional benefits and locavore credentials are impeccable, and it’s cultivated easily in the UK.
Kale it is then and no doubt three months of turnips every winter.