WASHINGTON — The White House on Tuesday morning unveiled President Obama’s blueprint for cutting United States greenhouse gas pollution by nearly a third over the next decade. Mr. Obama’s plan, part of a formal submission to the United Nations ahead of efforts to forge a climate change accord in Paris in December, detailed the United States side of an ambitious joint climate change pledge the president made in November in Beijing with the Chinese president Xi Jinping. In an effort to spur other countries to enact their own domestic climate change plans leading to the Paris accord, the leaders of...