In 2002, climatologists from Ohio State University who were working on the Quelccaya ice cap, in the Peruvian Andes, came face to face with a specimen of a kind of moss (Distichia muscoides), long stuck in the ice. Dated with carbon, the sample was found to be 5177 years old (more or less 50 years). According to the researchers, this discovery would be the consequence of global warming which erodes the largest tropical glacier in the world every year and has thus made the plant accessible. Today Quelccaya - which culminates in
some 5600 meters above sea level - losing thirty meters per year, a figure 40 times higher than in the 1970s. While it is true that the mass of glaciers tends to vary, Lonnie Thompson and his colleagues estimate that the age of the plant they unearthed illustrates the exceptional nature of the melting we are witnessing. Data from the National Climatic Data Center points in the same direction; they indicate that the ten warmest years recorded since global temperature measurements were
started at the end of the 19th century have all occurred since 1990.
WSJ 22 / 10 / 04 (When is plant emerges from glacier melting, is it global warming?)