Viruses are paragons of efficiency. They tote along only their genes, maybe a few proteins, and acquire everything else, from energy to temporary housing, through various acts of piracy. They are sometimes considered simple entities, inferior to living organisms because they do not possess cells. It is perhaps more accurate, however, to describe them as tiny, complex machines, whose reproduction is contingent on infiltration and manipulation of host cells, but whose persistence on Earth is made indefinite by the ability to lie dormant for many years and in extreme environments.
It is this latter capacity that has contributed to scientists’ concerns about the future of human health in a warming world. As temperatures rise, mosquitoes and certain other animal carriers of infectious viral diseases will expand their populations into areas that were once too cool or otherwise ecologically unsuited to support their survival. This alone stands to incite the spread of tropical diseases such asyellow fever, Ebola, and dengue, to areas north and south—to subtropical and temperate regions that are being gradually transformed by local and global climate change. But the warming of Earth’s atmosphere is likely to be exploited by viruses in other ways as well. For viruses that have been biding their time in a dormant state, locked away in ice or buried in rocks deep beneath Earth’s surface, slight increases in temperature offer an opportunity for reawakening./.../
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