Rivadeneira, M.M. and Fernandez, M. 2005. Shifts in southern endpoints of distribution in rocky intertidal species along the south-eastern Pacific coast. Journal of Biogeography 32: 203-209.
Climate alarmists routinely claim that global warming provides a strong impetus for poleward shifts in the ranges of both terrestrial and aquatic organisms, and that the warming of the globe over the latter portion of the 20th century was unprecedented over the past two millennia. If they are correct on these two points, we would expect to see substantial evidence of recent significant shifts towards higher latitudes in the high-latitude range boundaries of all sorts of plants and animals over the last half century. The authors of this intriguing new study look for such evidence in data pertaining to rocky intertidal species found along the Pacific coast of their homeland, i.e., Chile.
What was done
Rivadeneira and Fernandez determined mid-20th-century southern endpoints of the distributions of ten species of chitons and gastropods from museum collections and literature reviews, while current endpoints were obtained from field sampling conducted between 1998 and 2000.
What was learned
The Chilean scientists report that "of the 10 species analyzed, six presented significant changes in their southern limit, whereas four species exhibited no significant shifts." Furthermore, they say that "of the six species showing significant changes, only two expanded their southern limit, while the four remaining species exhibited significant range contractions," that is, their southern boundaries moved in a direction opposite to the direction climate alarmists claim they should have moved. In addition, Rivadeneira and Fernandez note that "the proportion of species showing contraction, expansion or no change did not differ from a chance expectation."
What it means
The results of the Chilean marine biologists suggest that the Pacific coast of Chile may be another one of the many parts of the earth that have not experienced unusual warming in recent decades. In fact, their analyses of temperature records collected at five coastal stations along the Chilean coast actually indicate cooling over the last half century at two of the locations; and they cite Rosenbluth et al. (1997) for their statement that "a cooling trend of air temperature has been recorded during the last century between 38°S and 41°S." Finally, they say that "generalizations about poleward shifts in species ranges cannot be made," although climate alarmists do it with gusto nearly every day.
Rosenbluth, B., Fuenzalida, H.A. and Aceituno, P. 1997. Recent temperature variations in southern South America. International Journal of Climatology 17: 76-85.