Last week scientists were extolling the virtues of duckweed—this week, another type of pond scum is being called a possible savior. Norwegian scientists believe microalgae could slash CO2 levels—responsible for a lot of our global warming woes—and even be tapped for a more effective biofuel in the future.

By taking exhaust fumes from carbon-burning plants and factories, mixing it with water so that the CO2 can dissolve into it and then pumping it into a “photobiorector” (a large transparent tube filled with microalgae), scientists can produce solar biofuel. The sunlight beating down on the tube presents the proper conditions for photosynthesis to take place, allowing the algae to convert CO2 into oxygen. The algae can later be removed and buried into the seabed, capturing the gases they take in.