The Bluetongue Curse of Climate Change
British scientists said recently that it was only a matter of time before bluetongue came to Britain and it had been described as the "new nightmare" for farmers.
Originally from Africa, the virus has taken advantage of rising temperatures to spread north, moving via Gibraltar, through Spain to devastate farms across Germany, France, Belgium and Holland, carried on the wind by midges
BTV has long been a problem globally, particularly in Africa and southern Europe, existing in a broad band from about 40 degrees north to about 35 degrees south. In recent years it has spread further north in Europe. The reason is thought to be related to climate change, allowing midges carrying the virus to survive in more northerly latitudes. In the last five years outbreaks have occurred, reaching 44 degrees north. That is some 800km further north than previously recorded.
As everyone in Scotland knows, midges are not confined to southern climes. What is particularly worrying is that the midge species in the affected areas, Culicoides imicola, can pass the virus on to other types of midge, such as the Culicoides obsoletus group and Culicoides pulicaris. Whether, if given the opportunity, the virus could also be passed on to the common biting midge of Scotland, Culicoides impuctatus, must be a matter of concern.
This is the disease the shepherds I know have been fearing, much more than F&M - but I worry to see Climate Change glibly blamed by the media. The situation is more complex. The virus has been restricted to areas very high summer temperatures, where an epidemic could occur, but generally lead to extinction during the (cold) winter. The wet spring of 2006, which was followed by an extremely long warm period in summer may have contributed to a higher than usual midge abundance and to a higher risk of BTV transmission. as the research says
It isn't just Scotland but even the arctic is famed for its midges so they are hardy little buggers. There have been large changes in our insect control measures and the farming landscape over the last few years. And not even the most ardent AGW scientist believes we have moved our climate 800km south, more like 100km is the highest estimate I have seen. The extreme weather may have helped last year, but is that climate change?