Potential environmental costs of Lithium mining in the context of climate change.

A. E. IZQUIERDO

Workshop; IWLiME 2016: 3rd International Workshop on Lithium, Industrial Minerals and Energy; 2016

Global lithium production has recently boomed in response to growing demand for rechargeable lithium batteries, which outstand as one of the most promising energy storage technologies [1]. Their applications are associated to technological innovations such us hybrid electric, plug-in hybrid electric and battery electric vehicles; which are mostly branded as ?green? alternatives to conventional technologies because they reduce CO2 emsisions, and release comparatively little polutants [2]. However, the main extractive process of lithium in brines is to produce lithium carbonate through evaporation and washing with sodium carbonate in lined shallow ponds [3]. This mining operation of salty flats requires relatively large amounts of water and may cause changes in freshwater availability in the ecosystem.Nearly 80% of the global lithium resources are located in the subtropical ?Puna? highlands of Argentina, Bolivia and Chile known as ?lithium triangle?. The Dry Puna is a biodiversity hotspot with high levels of endemism, unusual ecological or evolutionary phenomena, and global rarity of major habitat type. Water is the main limiting ecological factor in this region and wetlands are key functional units. High Andean wetlands are < 5% of the study area [4,5] (Figure 1); nevertheless contribute a significant proportion of primary productivity, maintain vertebrate populations, and regulate hydrological resources, sometimes affecting urban and agricultural areas downstream. Brine desiccation to obtain lithium could causes a decrease of the base level of groundwater in basins, thus reducing fresh water outside the edges of the salt flats, affecting the functioning of associated lakes and peatbogs.Additionally, most climate scenarios for high elevation ecosystems predict a 2-4 ºC increase in temperature[6], as well as decreasing water availability and longer dry seasons[7]. While models have more uncertainties for precipitation trends, the most accepted scenario suggest a decrease in precipitation and cloudiness for subtropical Andes[8]. Consistently, regional analysis of historical range of variability based on dendroecological reconstructions of water balance and ecosystem productivity shows a clear drying trend for the last 30 years [9,10]. If persistent, this trend could affect hydrologic dynamics of the region and biodiversity and Andean human population vulnerability. In summary, there is no doubth that low-carbon technologies represent a major progress in reducing global negative effects of economic growth and that the environmental impact of Lithium mining may be lower than other mining operations. However, when the resources demanded by these technologies come from very specific geographic locations, they can result in major local environmental degradation. This is potentially the case the Dry Andean highelevation wetlands, which with a few hundred thousand hectares appear bound to supply the lion share of the global lithium demand. Significant research effort is needed to understand the vulnerability of these ecosystems and their biodiversity to the combined effect of mining expansion and climate change. This effort should be coupled with clear national and transnational planning guidelines, such as long term monitoring; and it could be benefited from actions of transparency and public information in the private sector.