This is a valuable perspective on Colony Collapse Disorder in honey bees, and what CCD may mean in the larger picture of modern agriculture.
CCD is killing off large number of bee colonies in the USA and elsewhere in the world -- Europe, Canada, Asia. Apparently healthy bees -- especially the Italian bee commonly kept by beekeepers in the USA and Europe -- suddenly disappear, leaving the hives virtually empty. In just the last year or two, perhaps one-third or more of the world's honey bees have died from CCD. Many theories have been put forward about the cause of CCD, but scientists as yet have no clear answer.
Jacobsen's conclusion is that there is no single cause. Many factors may be involved: Loss of habitat, weakening of bee colonies due to the varroa mite, monocultural agriculture on an industrial scale, massive and "unnatural" movement of bee hives by beekeepers for pollination of crops, use of antibiotics and miticides in hives, use of insecticides in agriculture, possibly in a few cases genetically modified crops and other etiologies. Jacobsen argues that several of these factors can contribute to poor nutrition in bees, to the disturbance of the overall "hive intelligence" and to many different problems that, when they reach a tipping point, cause the collapse of bee colonies.
In the end, Jacobsen's argument about bees and CCD is unconvincing. The "multi-cause" hypothesis simply doesn't explain why such a large number of bee colonies died suddenly and in such a short time, nor why CCD is present in many areas of the world where many of the causes he discusses (trucking bees long distances for pollination, monocultural agriculture, GM crops, and so on) aren't common.
However, Jacobsen's larger argument, unfortunately made superficially and without much data beyond the bees, is that with today's agricultural practices, including our current style of beekeeping, we run the risk of losing not only honey bees but pollinators of all kinds. That would be a disaster on a massive scale.
Jacobsen's heart is in the right place, and he yearns to go back to an older, more sustainable model of agriculture.
If nothing else, he has motivated me to look into taking up beekeeping again.