Could Glowing Algae Tanks Replace Street Lamps and Fight Climate Change?
A glowing tank of green algae on a city sidewalk might sound like something out of a science fiction film, but researchers say it could be one of the most practical tools cities have against ever-increasing carbon dioxide (CO₂) emissions.
Cities are the planet’s biggest polluters. According to the United Nations Development Programme (UNDP), cities are the source of as much as 75% of total CO₂ emissions worldwide. Trees help, but dense urban environments often lack space and soil for them to survive.
Transparent tanks of living microalgae could be the solution.
A great example is Serbia’s LIQUID 3, nicknamed the “liquid tree.” Designed by Dr. Ivan Spasojevic of the Institute for Multidisciplinary Research at the University of Belgrade, LIQUID 3 is a 600-liter transparent tank of microalgae that absorbs CO₂ from the surrounding air and converts it into oxygen through photosynthesis. According to its developers, microalgae are 10 to 50 times more efficient at fixing CO₂ than trees, and one unit is equivalent to one adult tree or 200 square meters of lawn.
The first unit was installed in September 2021, in an area so polluted that trees struggle to survive there, and was recognized by the UNDP as one of the 11 best climate-smart urban solutions in Serbia. Each unit also functions as street furniture, having a built-in bench, mobile phone chargers, and a solar panel for nighttime lighting.
“This seems pretty plausible to implement near Skyline,” IB Biology HL 2 student Andrew Chu has said, “It wouldn’t be difficult to install and could definitely make an impact on emissions in the Pacific Northwest.”
The concept is spreading globally. In India, researchers developed the Smart Algal Liquid Tree (SALT), a 100-liter mobile photobioreactor designed specifically for placement in schools, offices, and other interior spaces to reduce greenhouse gas emissions and improve local air quality.
For more information:
The first algae air purifier in Serbia — United Nations Development Programme
Liquid Tree to Combat Air Pollution in Belgrade — EUKI / Balkan Green Energy News (2022)
Boosting Algae’s Carbon Absorption — Nature India (October 2024)
