The Arctic Paradox: Impacts of Climate Changes on Rivers from the Arctic and the Semiarid Increase Mercury Export to the Ocean [O Paradoxo ártico: Impacto das Mudan as Climáticas Sobre Rios árticos e do Semiárido Aumentam a Exporta o de Mercúrio para o Oceano]

The semi-arid coast of Brazil is being strongly affected by regional land use and global climate changes, resulting in decreasing continental runoff to the ocean and increasing the water residence time in estuaries and expanding mangrove areas; these in turn may induce an increase of particulate Hg accumulation within the estuaries and increase the export of dissolved Hg to the ocean. This is, paradoxically, what is presently happening in Arctic rivers due to increasing, not decreasing, continental runoff associated with global climate changes.