The water isn’t for drinking. It’s salty, warm and thick with microscopic algae: tiny organisms that might be the future of green energy. In a world that relies on oil, fuels made from these organisms could offer a lower-carbon alternative to diesel, providing cleaner energy for trucks, planes, boats and pretty much anything else with a diesel fuel tank. “We’re working to decrease our overall carbon footprint,” says Kelsey McNeely, who leads ExxonMobil’s biofuels research and development. “I think that’s why we recognize fuels made from algae and plant-based sources could be part of the solution……..