Marine organisms with tiny calcium carbonate shells play a bigger role in regulating the Earth’s climate than we thought. Researchers discovered that these calcifying plankton, which include coccolithophores, foraminifers, and pteropods, are often overlooked in climate models. This gap may lead us to underestimate crucial elements of the ocean’s carbon cycle and its response to climate change.
A study by experts from the Institute of Environmental Science and Technology at the Universitat Autònoma de Barcelona emphasizes that these organisms play a key role in how carbon moves from the atmosphere to the ocean’s depths. Their unique traits matter for understanding Earth’s overall systems.
Tiny Shells, Big Impact
These shell-builders create small shells from calcium carbonate. As they live and die, their shells affect ocean chemistry and carbon transport. Lead author Patrizia Ziveri pointed out that while these plankton may be small, they significantly influence ocean and climate chemistry. Excluding them from climate models could mean missing important processes that shape how Earth’s systems react to climate change.
Missing Details in Climate Models
Standard climate models often simplify or ignore these plankton. This means important processes, like how shells dissolve in shallower waters, aren’t fully captured. Many shells don’t make it to the seabed; instead, they dissolve near the surface, impacting local carbon dynamics. This omission may skew our understanding of how much carbon is stored in oceans, where it goes, and how quickly it moves.
Not All Shell-Builders Are the Same
The study highlights that not all calcifying plankton are equal. Coccolithophores, for instance, are significant CaCO₃ producers but are sensitive to ocean acidification. Foraminifers and pteropods have different traits and vulnerabilities. By grouping them all together, climate models risk losing important details that affect predictions.
The Oceanic Carbon Pathway
The review also points out that many factors influence how shells sink and how carbon is exported to the deep ocean. Processes like predation and microbial respiration play a role in determining how much carbon leaves the surface. If these factors aren’t considered, we might misunderstand the ocean’s ability to absorb CO₂ or release it back into the atmosphere.
Learning from Ancient Shells
Integrating these plankton dynamics into climate models not only sharpens current forecasts but also enhances our understanding of past climates. Analyzing calcium carbonate layers can help us reconstruct historical ocean conditions, giving us insight into how our oceans have changed.
Bridging Research and Climate Models
To fill in the gaps, experts suggest several steps. They propose better quantification of the production and export rates of different plankton groups. Laboratory and field studies that assess how each group responds to various climate stressors—like warming or acidification—are crucial. Once we gather this data, translating it into actionable insights for climate models will ensure biology is a core component rather than an afterthought.
Ziveri noted that paying attention to the smallest ocean organisms could enhance our understanding of significant climate dynamics. This could lead to better predictions about how ecosystems and societies will be affected by climate change.
The Importance of Microorganisms
Ultimately, this research serves as a reminder that climate systems encompass more than just physics and chemistry; biology plays a vital role too. The impact of these tiny shells may seem negligible at first glance, but collectively, they influence ocean chemistry, carbon export, and broader climate feedback systems. Ignoring their contributions might hinder our understanding of how resilient or vulnerable our oceans—and climate—will be in the future.
For a deeper look, you can find the study published in the journal Science.
