Bloomberg: Investing in climate change used to mean financing the fight against global warming. Morgan Stanley, Goldman Sachs Group Inc., and other firms took stakes in wind farms and tidal-energy projects, and set up carbon-trading desks. Then, as efforts to curb greenhouse-gas emissions faltered, the appeal of clean tech dimmed: Venture capital and private- equity investments fell 34 percent last year, to $5.8 billion, according to Bloomberg New Energy Finance. Now the smart money is taking another approach:...