Ron Naveen has been counting penguins on a remote, inhospitable stretch of Antarctica for nearly four decades. He's one of the few people who still counts these adorable, flightless, slightly awkward birds by hand. Penguins have survived a host of environmental changes over 60 million years. But Naveen says climate change could mean the end for two species of his favorite Antarctic birds. Here's why. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders