By Joern Fischer
As we know, global maps are the definite go when it comes to getting published where it matters, getting attention of policy makers, and getting attention of the media. Making global maps has also become much easier in the last couple of decades, and so now we have global maps of just about everything. Of the things that interest me, this includes, for example carbon sequestration, biodiversity loss, land cover, land clearing, food production, yield gaps.
My point today is very simple: we can map all of these things globally, but for some it’s meaningful and for others far less so.
Let’s say we create a global map of carbon sequestration, which tells us about the spatial distribution of opportunities for better climate regulation. This seems to make sense, in that the carbon thus sequestered automatically benefits everyone in the world — basically, no matter where it happens.
But more common maps these days are about resolving food-conservation dilemmas, e.g. by highlighting yield gaps or opportunities to share or spare land, and so on. For everything related to food production, things are different than with carbon. The food generated in one place does not automatically benefit the whole world! So, unlike for carbon, the “produce first, distribution will look after itself” principle, is fundamentally flawed when it comes to food.
For biodiversity it’s also a bit tricky, because it’s not as easily commensurable globally as carbon is. The carbon sequestered in South America, for example, does much the same thing for climate regulation as that sequestered in Northern Europe. But how does a culturally valued bird in an indigenous community of Northern Australia (for example) rank relative to a yet undiscovered epiphyte in the Amazon basin?
So we have at least two things to keep in mind when mapping things: (1) Do the benefits of the things mapped distribute themselves automatically? And (2) how commensurable are they across the globe? Where the answer is shaky on both of these things, we may need to be a bit more careful about getting too excited about global maps.
Visualising global patterns is nice, but it would be good if we didn’t lose touch with smaller scales quite as much. Many real-world problems about conservation and about food security, for example, play out at regional or landscape scales. Global analyses are nice for an overview, but actual problems can rarely be solved very well on the basis of global analyses.
[Incidentally, even if the desired effect of something is the same worldwide (as for carbon sequestration, say), the extent of undesired side-effects may differ from place to place… and again, those side-effects would not be apparent by just looking at the global pattern…]