Bloomberg: President Barack Obamas determination to reverse Bush administration policy on combating climate change is a huge deal that will help produce a global agreement this year, a United Nations envoy said. “They have a huge willingness to come up with an ambitious plan and reach an agreement,” the UN’s Yvo de Boer told reporters at the UN today after meetings this week in Washington with congressional leaders and Obama administration officials. De Boer is charged with overseeing …