Reuters: Human activity and the El Nino weather pattern over the last century have warmed West Antarctica, part of the world’s coldest continent, according to a study based on four years of collecting ice core data. The West Antarctic warmed in response to higher temperatures in the tropical Pacific, which itself has been warming due to weather patterns like a major El Nino event from 1939 to 1942 and greenhouse emissions from cars and factories, according to the study. “An increasingly …