Food and Global Warming

4 June 2008

World leaders are finally realizing that we're facing a food crisis: they're currently having a meeting in Rome to discuss it, and UN chief Ban Ki-moon recently stated that we need to grow 50% more food by 2030 to satisfy needs (I believe this is a conservative estimate). This is not much of a surprise to me -- I mentioned the upcoming food crisis in my earlier article on biofuels, and it's also related to the energy situation I discussed before that . Both the energy and food crises-to-be are largely due to a combination of a world population that is growing quite fast (expected to double by 2050), and a rise in the standard of living in some parts of the world (people with higher standards of living tend to use more energy and consume more food). This growth is not sustainable, as far as I can tell.

It has been suggested that to make our way of life more sustainable, we ought to shop locally (see my previous blog entry for discussion). But yesterday I read an article in Science news, based on a study published in Environmental Science and Technology, that I thought made an interesting point: the type of food we eat has a much greater environmental impact than how far it has traveled to reach us, at least in terms of greenhouse gas emissions. The study authors looked carefully at all parts of the process by which we obtain food, and found that the bulk of the greenhouse gases (83%) came from food production, with only 7% from farm-to-store transportation. Therefore, switching to buying only locally-produced food doesn't really address the bulk of the problem. Instead, we need to think about the production phase: we can get about the same reduction in greenhouse gases by replacing red meat and dairy products with chicken, fish, eggs, grains, or vegetables just one day per week, as we can by buying all of our food locally. This has other benefits as well, in terms of the food crisis: a lot of the grain we grow is fed to animals to produce a much smaller amount of meat and dairy products, so shifting to eating the grains directly can also help alleviate the food crisis. Maybe we'll all need to become vegetarians soon?