When Jason Smerdon opened up a retirement account as a graduate student two decades ago, he gravitated toward socially responsible stock funds, despite the possibility of weaker returns. He figured his ideals were more important than investment performance. Fast forward two decades, and his investment philosophy is no longer as black and white. Since the economic downturn a decade ago, he has moved a majority of his retirement portfolio into aggressive growth funds and only factors environmental concerns into the equation when investing in individual stocks. All of that consciousness came in ‘08 and ‘09 when I realized I don’t want to be caught in a conservative trap where I’m not beating inflation.”Smerdon isn’t an ordinary investor worried about the future of the planet. He’s a climate scientist at Columbia University’s Lamont-Doherty Earth Observatory and co-director of the Earth Institute’s undergraduate program in sustainable development.