The Butterfly and Global Warming

            I posted an entry a while back about a computer program that captures news articles about global warming and global climate change, and rates the responses.  That program found some news articles about the Poweshiek skipper, Oarisma poweshiek, and its listing as a “candidate species” under the United States Endangered Species Act.  Those news articles mentioned global warming as one of the threats to the species.

            I hate that.

            When scientists get together to try to prevent a species from becoming extinct, they look at a number of things.  What caused the species to decline?  What are the threats to the species in the future?  Then they list those causes and threats.  Usually they can come up with a couple dozen threats, many of which are significant.  Probably they miss some significant threats because they are unknown.

            Global climate change is certainly a threat to this species in the future.  It may have contributed to its recent decline as well, because freaky weather patterns can wipe out a species that is already found only in small isolated population islands.  This butterfly disappeared from Iowa and Minnesota sometime between 1999 and 2005, and there was unusually severe weather during that time period.  However, there were a number of other factors which could have caused the demise, including some that may have not been identified yet.  My money is on the landscape scale spraying of insecticides, particularly in response to soybean aphid outbreaks.  In some of the years within that timeframe, fully one third of the landscape was sprayed for aphids.  But there are at least half a dozen things that could be as likely.

            My problem with climate change is that when it enters the public discourse for every endangered species the ecologists have already lost the argument.  There is the fatalistic aspect—this species will go extinct because of climate change, so we can only prolong the agony.  Then there is the problem with focus—the whole environmental debate becomes about carbon emissions.  Drill an oil well, and ignore the threats to the ground water or the emissions of toxics—what is the carbon footprint?  Put in a wind generator, and no one objects to the permanent conversion of a half-acre of land for the foundation, roads and lines that must be built to service the generator, local climate effects, and on and on.

            Global warming is a global problem, and must be dealt with globally.  We as humans have not established that we are able to do that yet.  However, most of the threats to species are caused by small, local incremental changes—land use, land management, use of pesticides, hydrogeological changes.  Those changes can be managed on a local scale, and, while it is not always easy, we have established that we can do that.

            So unless global climate change is a root cause of the danger to a species, can we try to keep it out of the public discourse?

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About the roused bear

Nature photographer from central Iowa.
This entry was posted in butterflies, oarisma poweshiek and tagged , , , . Bookmark the permalink.

One Response to The Butterfly and Global Warming

  1. Finn Holding says:

    Very good point, well made.

    Climate change is one of many factors in decline of an individual species, but as you say it needs to be placed in context with all the other threats such as pesticide use.

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