We don’t yet know if H5N1 bird flu will spill over from animals to infect a large number of humans. It’s my belief that humans have an obligation to the nonhuman life we share this planet with to mitigate the harm we’ve enabled this virus to cause. But even if you don’t share that conviction, it is still in our best interest to keep this virus from spreading. Wild birds are routinely exposed to mild viruses, but are seldom killed by them. Humans, however, have introduced factors that favor disease: A warming climate can weaken avian immune systems, and infections spread more easily when birds come into more frequent contact while sharing what little habitat remains.

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Organizations: World Health