They found that the aquatic habitat of today is much different from that of pre-industrial times. More fossils of the type that live in open water environments were found in the top (most recent) layer of sediment an indication that these lakes have less ice cover and a longer growing season that would alter important lakewater properties such as light availability and the way lakes stratify, as a result of warming. This marked a major ecological shift in the lakes that coincides with a period of increased human industrial activities and emissions in more southern regions.
Earlier PEARL studies in the High Arctic tundra had indicated major changes in the different layers of fossils associated with climate warming. The new findings bring the effects of climate change closer to populated areas. "The logical extension was to see if tree-line lakes also show these dramatic changes, and this study confirms that the impact is even greater than previously documented," says Dr. Rhland. "We believe that the consequences of greenhouse gas emissions, in the form of climate change, are already having a notable impact on the Arctic environment."
As well as affecting plant and animal life in this region, melting permafrost and less ice cover are already beginning to have repercussions on human concerns such as transportation, housing, and even sovereignty issues.
Last year an entire Nunavik community was relocated by the Quebec government after melting permafrost caused houses to slide from their foundations. Other researchers have found evidence that ocean ice is thinning, which could have future implications for intercontinental transportation routes.
"Until recently, no one was reconstructing Arctic climates in this way, because the technology didn't exist," says Dr. Smol. "Now that we can, in essence, reconstruct the past through this indirect technique, we're filling in gaps in our knowledge and finding answers to many ecological an
Contact: Nancy Dorrance