Interactions between Climate Change and Contaminants

Climate change can interact with toxic contamination to impact wildlife via climate change–altering exposure to contaminants or via toxins altering wildlife responses to climate change. Climate change–induced physical shifts in the environment, such as melting sea ice, glaciers, snow and permafrost, changing lake chemistry, and more frequent and intense wildfires and precipitation, can increase the movement and redistribution of contaminants in the environment. Moreover, climate change can also shift species ranges, where increased temperatures facilitate prey shifts to more southern, more contaminated prey by Arctic predators. We provide two case studies showing how climate-induced abiotic and biotic changes, respectively, influence contaminant levels. In addition, a major factor in determining the resilience of wildlife to climate change is their behavioral plasticity to accommodate changes in food availability. However, contaminants may disrupt hormones that allow such behavioral plasticity; thus, the effects of climate change on endocrine and immune function may be exacerbated by contaminants. Further, increasing concentrations of carcinogenic contaminants, coupled with weakened immunity from toxins, may lead to increasing rates of cancer and other diseases in wildlife populations. These threats can cumulatively impact wildlife and may lead to high contaminant burdens and increased mortality in the face of persisting climate change.