New research shows that climate change is causing the Earth's ice sheets to shrink much faster than previously thought -- the annual rate of sea ice loss has more than tripled since the 1990s. In the Arctic, melting ice is raising geopolitical tensions, kickstarting a global race for potentially priceless minerals, oil deposits and shipping routes. Lisa Desjardins reports. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders