
Global production of meat has risen dramatically from 130 million tonnes in the late 1970s to 230 million tonnes in the year 2000. Meat is now the single largest source of animal protein in all affluent nations and demand for animal flesh is expected to more than double by the year 2050. In order to meet this growing appetite, animals will no doubt be reared more intensively and cheaply with factory farming and aquaculture (fish farming) causing further pollution, water and land usage. If nothing is done, the environmental impact of meat production can only increase."
http://www.vegsoc.org/
I think the idea is quite clever, and the way the ad has been executed is good as well. The ad is nearly almost all in gray scale, and the typeface used on the ad suits the tone of voice the vegetarian society is trying to create. Along with the cow as the main image, with a white background that adds a high contrast between the layers.