The burgeoning amount of carbon dioxide in oceans is affecting a lot more than coral reefs. It is also damaging marine life and, most ominously, threatening the future survival of marine populations.

The world's greatest lake, holding 20 percent of the planet's surface fresh water, has long remained one of the most pristine places on earth. Now, as Russia's economy booms and its climate warms, the Siberian lake faces new threats.