OneWorld US: The United States and China can overcome their diplomatic gridlock on climate change by focusing on mutually beneficial, large-scale programs including clean energy systems, says a new report from a Washington, DC think tank. “The time for large-scale U.S.-China cooperation on climate change and clean energy is now,” says the report from the public policy research center Brookings Institution. “Unless both countries change course soon, ongoing investments in 20th century technologies …