New research shows that even modest temperature increases, within the range already caused by climate change, can significantly disrupt microalgae behavior. Microalgae are responsible for a large portion of global carbon dioxide absorption and form the base of aquatic food chains. The study found that a 5 degree Celsius rise caused a 20 percent increase in cell density but also delayed photosynthesis by several days, potentially reducing how much CO2 these organisms can lock away. Researchers observed that the algae's swimming behavior changed within 15 minutes of a temperature shift, and their metabolism shifted away from photosynthesis toward organic carbon sources. This suggests that as waters and soils warm, the natural carbon capture performed by microalgae could become less reliable. The findings highlight a hidden vulnerability in climate feedback loops that could affect everything from oxygen production to food web stability. For anyone tracking climate impacts beyond obvious metrics like sea level rise or storm intensity, this study is a reminder that small changes in temperature can have outsized effects on the biological machinery that keeps the planet's carbon cycle running. The research was published in The Plant Cell and conducted by the Cluster of Excellence Balance of the Microverse.
