A new study conducted by Cornell University reveals that artificial ponds have a significant impact on greenhouse gas emissions. Two related studies conducted by researchers at Cornell are beginning to quantify the effects of both artificial and natural ponds on the global greenhouse gas budget, providing valuable insights into a poorly understood topic.

The studies found that when the emissions and carbon storage of artificial ponds are combined, they can be net emitters of greenhouse gases. Previous estimates suggest that ponds, defined as bodies of water 5 hectares or smaller, can contribute to 5% of global methane emissions. However, without precise measurements in many ponds, this percentage could vary between half and double the estimated amount. Additionally, there are limited estimates of carbon burial rates in ponds.

One study conducted by the researchers focused on the amount of carbon sequestered in 22 specifically selected ponds. The researchers examined past management activities and measured sediment thickness and carbon content in the ponds. They found that carbon burial rates in ponds were influenced by factors such as aquatic plants, fish, and nutrient levels. The study also revealed that both natural and artificial ponds sequester a significant amount of carbon, indicating that carbon sequestration in ponds is underestimated.

The second study explored seasonal greenhouse gas emissions in specific experimental ponds at Cornell. Methane, a potent greenhouse gas, accounted for the majority of emitted gases. The study also highlighted the importance of frequent sampling to accurately account for greenhouse gas emissions from ponds.

Overall, these studies suggest that ponds play a role in greenhouse gas emissions and carbon storage. While currently ponds may be net emitters of greenhouse gases due to methane release, there is the potential for them to become net sinks by reducing methane emissions. The findings also propose the use of bubblers or underwater circulators to reduce methane emissions in ponds.

Further research and a better understanding of the role of ponds in greenhouse gas emissions are crucial for accurate climate modeling and predictions.

Sources:
– Meredith A. Holgerson et al, High rates of carbon burial linked to autochthonous production in artificial ponds, Limnology and Oceanography Letters (2023). DOI: 10.1002/lol2.10351
– Nicholas E. Ray et al, High Intra-Seasonal Variability in Greenhouse Gas Emissions From Temperate Constructed Ponds, Geophysical Research Letters (2023). DOI: 10.1029/2023GL104235

Source: Cornell