Climate change enhances the mobilisation of naturally occurring metals in high altitude environments.
Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment.
Biosphere-2, University of Arizona, Tucson, AZ, USA; Faculty of Biological Sciences, University of Vigo, Vigo, Spain; School of Natural and Built Environments, Kingston University London, UK. Electronic address: zaha_dragos@yahoo.com.
Dragos G
DG
Zaharescu
School of Natural and Built Environments, Kingston University London, UK. Electronic address: p.hooda@kingston.ac.uk.
Peter S
PS
Hooda
Biosphere-2, University of Arizona, Tucson, AZ, USA; Faculty of Biological Sciences, University of Vigo, Vigo, Spain. Electronic address: bcarmen@email.arizona.edu.
Carmen I
CI
Burghelea
Southwest Research Center, United States Department of Agriculture, Tucson, AZ, USA. Electronic address: viktor.polyakov@ars.usda.gov.
Viktor
V
Polyakov
Faculty of Biological Sciences, University of Vigo, Vigo, Spain. Electronic address: apalanca@uvigo.es.
Antonio
A
Palanca-Soler
D000393:Air Pollutants / Q000032:analysis*; D000531:Altitude; D057231:Climate Change; D004784:Environmental Monitoring; D008670:Metals / Q000032:analysis*
D000393:Air Pollutants; D008670:Metals
Climate change; Contaminant risk; High altitude; Lakebed sediment record; Trace elements; Weathering and transportation