Guardian: The warming of the Arctic is releasing toxic materials such as pesticides and industrial chemicals that have been trapped in ice and cold water. Called persistent organic pollutants (POPs), the manmade compounds, which can cause cancers and birth defects, were banned under the 2004 Stockholm Convention. Because POPs take a very long time to degrade, they can be transported long distances in the atmosphere; the low Arctic temperatures then induce their disposition, according to the researchers, who published their findings in Nature Climate Change. The amounts of POPs that are released will depend on the speed of warming and on the chemicals’ interactions with snow and rain.