After a century of shooing away hunters, tending to trails and helping visitors enjoy the wonder of the natural world, the guardians of America’s most treasured places have been handed an almost unimaginable new job – slowing the all-out assault climate change is waging against national parks across the nation. As the National Parks Service (NPS) has charted the loss of glaciers, sea level rise and increase in wildfires spurred by rising temperatures in recent years, the scale of the threat to US heritage across the 412 national parks and monuments has become starkly apparent. As the National Parks Service...