A new study shows the Arctic Ocean is becoming more acidic as it absorbs soaring carbon dioxide emissions in a shift that could imperil the ecosystem. According to an international team of scientists, the average acidity of surface ocean waters across the globe has increased by roughly 30 percent over the past two centuries. Experiments have shown the acidification process could drive some species to extinction. Researcher Richard Bellerby told the BBC: “We have already passed critical thresholds. Even if we stop emissions now, acidification will last tens of thousands of years.”