Agence France-Presse: US President Barack Obama and Japan’s Prime Minister Yukio Hatoyama agreed Friday to work together in combating climate change, at a meeting ahead of a key UN summit in Copenhagen next month. Obama and Hatoyama said they "aspire to reduce" each nation’s greenhouse emissions by 80 percent by 2050, and to seek a global cut of 50 percent by then — matching a goal set by the Group of Eight rich nations. As Obama visited Japan on his Asia tour, the leaders in a joint statement …