Associated Press: The U.N. secretary-general on Wednesday challenged investors around the world to at least double their investments in clean energy by 2020, saying that "we must begin the shift away from fossil fuels immediately." Ban Ki-moon told an investor summit on climate risk that increasing investment in clean energy is critical in following up on the landmark agreement to tackle climate change reached in Paris last year. Ban said about $330 billion was invested in clean energy last year, but that is far...