Visiting China last year got me thinking about meat. Part of this was because as a vegetarian it was a fun daily challenge to find meat-free food often involving 2 -3 hours wandering around huge, smog-filled cities. Meat in China is ubiquitous and best summed up by the old joke that “Chinese people eat everything with legs except tables, everything with wings apart from planes.” I really admire the Chinese attitude of eating everything from duck’s tongue, to chicken’s feet, but looking at the graph below it is obvious that the amount of meat in Chinese diets is also increasing rapidly.
As with most countries meat consumption in China is made up of a mixture of imported and domestically produced meat. This means that the ecological consequences of diets in China and nearly all countries are felt at home as well as abroad. I have written previously on the impacts of meat consumption for biodiversity and why I think ecologists should eat less meat. Some comments on that post pointed out that not all meat has the same environmental cost. This is undoubtedly true. However, I’m not sure that these costs are quite as simple as I, and others, initially thought.
The comparison that is often made to highlight differed impacts is the difference meat production in tropical and temperate part of the world. Tropical cattle farming often involves clearance of forest or savannah for production of feed and grazing land. In contrast temperate cattle often graze on centuries old pastures with supplementary feed imported from other regions. Therefore the forest clearance associated with tropical cattle production must make it worse, right? Well, yes and no.
Firstly just because the loss of ecosystems in temperate regions happened centuries or millennia ago doesn’t mean that current farming has no impact. Grazing stops ecological succession and recovery of ecosystems that may otherwise be forest. However, the fact the conversion from natural to managed systems happened such a long time ago means that this impact is less obvious. Most Europeans live somewhere that has had widespread agriculture for generations and so this is perceived as being perfectly normal. Traditional agricultural landscapes, which elsewhere would be seen as degraded ecosystems, are even seen as being in need of protection in the EU. This raises potentially interesting questions such as “Are cultural services prone to shifting baseline syndrome? And if so, couldn’t massive loss of biodiversity occur without any long term effects on these cultural services?”
If we accept that both past and present destruction of ecosystems have a negative effects on biodiversity and some ecosystem services then this raises the question of where these impacts are likely to be greater. If we think that species with small populations or range sizes are the species of highest conservation priority then it is clear that impacts in the tropics are likely highest. These regions have more species and more of these species have small ranges. We could of course argue for different methods of prioritisation for biodiversity but for the moment I’ll just stick with this one.
When it comes to carbon emissions and sequestration the picture is less clear. Though tropical forests tend to have very high carbon stocks plenty of intact temperate forests have similar carbon density (see below). As such any regrowth of forests in temperate regions represents a potentially important contribution to climate change mitigation. How other ecosystem services are affected is unclear.
I am obviously not proposing that cattle ranching in the tropics is a good thing. However, I think we need to stop kidding ourselves that meat production doesn’t have profound impacts on ecosystems – it clearly does, whether your beef comes from Britain or Brazil. The best way to reduce this impact is by eating less of the stuff.