The number of emperor penguins has plummeted primarily due to climate change that causes the sea ice where they live, hunt and breed to break up earlier in the year. Greater protections for endangered emperor penguins and how to manage growing tourism will top the agenda at talks on Antarctica opening in Japan on Tuesday. Officials from the nearly 60 countries signatory to the Antarctic Treaty are meeting in Hiroshima for annual discussions on protecting and managing the fragile region. The continent and its abundant wildlife are protected under the 1959 treaty , which designates it as a land of science and peace, while freezing territorial claims. "The discussions taking place here in Hiroshima are especially important at a time when Antarctica is increasingly affected by global challenges such as climate change," Francisco Berguno, executive secretary of the Antarctic Treaty Secretariat, told a news conference Tuesday.…