Ten years ago, I went to Costa Rica on an ecotour. On a hike through the rainforest, our guide would point out different plants by name, and would always have some interesting comment about one or other. The plant that makes Vincristin, the anti-cancer drug, for example. Or berries that birds would eat because the capsaicin in them would help expel parasites. The names of these plants have long escaped my memory, but one thing stayed with me. Frequently, he would point out trees and shrubs that originated from India or Africa, recent arrivals brought to central America both intentionally and accidentally. The vast increase in global shipping has now made the homogenization of climatic zones rapidly apparent.
Others have commented on the disturbing bee colony collapse. And there is now news of an emerging fish population collapse in the Great Lakes caused by VHS presumably brought in by a foreign ship. As global warming increases, the range of habitats into which otherwise obscure pathogens can propagate is likely to become a sudden, very unpleasant surprise as animals and plants upon which we still depend become prey to diseases we don't even know exist in many cases.
The bee problem has received its share of far-out theories, e.g. cell phones, but the simplest explanation is often right. Pathogens, strange new pathogens, may now be bursting out of their previously restricted niches. The powerful intersection of the global movement of goods and global climate change threatens to unleash sudden, rather than gradual, catastrophes upon us. Perhaps we are seeing the first big signs of discontinuities emerging in what has been seen until now as a relatively linear process of climate change.