Whales not to be counted on as ‘climate savers’: study

Newswise — Can whales enhance the process of carbon removal from the atmosphere?

According to recent research conducted by Griffith University and a global team of scientists, it has been discovered that the capacity of whales to capture carbon is insufficient to significantly impact the trajectory of climate change.

Dr. Olaf Meynecke, along with a team from the Whales and Climate Research Program led by Professor Brendan Mackey and Dr. Jasper De Bie at Griffith University, conducted a comprehensive analysis of the various methods through which baleen whales, including humpback whales, contribute to the removal of atmospheric carbon on both regional and global scales.

After careful examination, the research team determined that the quantity of carbon potentially sequestered by whales is insufficient to create a notable impact on the overall course of climate change.

Dr. Meynecke emphasized that while whales play a crucial role in the marine ecosystem, their contribution to the global carbon cycle is relatively minor, making it impractical to rely on them as a significant means of reducing atmospheric carbon levels.

Dr. Meynecke expressed the desire of the research group to promote the positive aspects of whale conservation and explore the potential for using carbon credits to support further research. However, they believe that presenting whales as a significant solution for carbon reduction would be misleading and create unrealistic expectations. It is important to approach the debate with clarity and avoid generating false hope.

“This is in contrast to media perpetuating whales as climate engineers.  

Dr. Meynecke cautioned against creating unrealistic expectations regarding the role of charismatic species as climate engineers. They emphasized that fostering false hope could potentially hinder the necessary behavioral changes required to mitigate the catastrophic impacts of climate change. Moreover, such delays could indirectly affect the recovery of whale populations and their overall well-being. It is essential to address climate change with a comprehensive and multifaceted approach rather than relying solely on charismatic species as a solution.

The research team emphasized the significance of the ocean carbon cycle as a key driver of the Earth's climate. They stressed the importance of conducting further investigations to bridge existing gaps in our understanding of whale ecology. By gaining more insights into these areas, we can better elucidate the specific contribution of whales to the ocean carbon cycle and its overall impact on the climate system. Such research will contribute to a more comprehensive understanding of the role whales play in shaping our environment.

Whales have other ways to aid carbon capture: via their biomass storing carbon for decades (depending on lifespan); and when a whale dies, sinking to the ocean floor where sediment may eventually cover it.

Dr. Meynecke pointed out that while whales play a crucial role in maintaining the health of marine ecosystems, exaggerating their capacity to counteract or offset human-induced alterations in global carbon budgets could inadvertently divert attention from the well-established methods of reducing greenhouse gas emissions. It is important to focus on established strategies for mitigating climate change rather than solely relying on the potential contribution of whales in order to address this pressing global issue effectively.

The team argues that previous estimations have overlooked the comprehensive temporal and spatial scales at which carbon sequestration takes place. They contend that certain pathways, like whale falls (where whales die, sink to the ocean floor, and retain carbon for extended periods), have been underestimated. Additionally, the researchers highlight the significance of considering the respiratory activity of whales, which is often not adequately accounted for in carbon sequestration assessments. By addressing these limitations and incorporating a broader understanding of whale ecology, we can gain a more accurate representation of their impact on carbon dynamics.

It is crucial to recognize that there exist other aspects of whale conservation that hold greater significance than their role in carbon capture.

Implementing widespread protection measures for marine environments, including the preservation of whale habitats, will enhance resilience and contribute to natural carbon capture on a global scale.

The research study titled "Do whales really increase the oceanic removal of atmospheric carbon?" has been published in the journal Frontiers in Marine Science, specifically in the Marine Megafauna section.

This research was assisted by funding to the Whales and Climate Research Program.