The Unseen Impact of Human Activities on Earth’s Deep Subsurface

The impact of human activities on Earth’s surface has been extensively studied, but what about the deep subsurface that lies beneath the planet’s surface? A recent study conducted by hydrology researchers from the University of Arizona sheds light on how humans are affecting Earth’s deep subsurface. The study reveals how activities such as oil and gas production, geothermal energy extraction, and lithium extraction are altering the circulation of fluids in the deep subsurface.

The study, detailed in the journal Earth’s Future, highlights how the rates of fluid production from human activities surpass the natural background circulation of water in the deep subsurface. According to lead study author Grant Ferguson, human-induced fluid fluxes are projected to increase in the future with strategies proposed to combat climate change. These strategies include geologic carbon sequestration, geothermal energy production, and lithium extraction from underground brine for electric vehicles.

Implications for the Future

Professor Peter Reiners emphasizes the importance of responsible management of the subsurface for a sustainable future and to mitigate the effects of climate change. The study, conducted in collaboration with researchers from various institutions, raises awareness about the environmental impacts of human activities on Earth’s deep subsurface. As human intervention increases, there is a growing concern about how these activities will be reflected in the geological record.

With oil and natural gas production, there is a cycle of producing fluid and reinjecting it into the deep subsurface. This process is also seen in geothermal energy production, geologic carbon sequestration, and lithium extraction. The study shows that the fluid movement rates induced by human activities exceed those from natural processes. This increased fluid movement has the potential to alter not only the deep subsurface fluids but also the microbial communities living there.

Despite advancements in understanding Earth’s deep subsurface, there are still many unknowns regarding how human activities impact this hidden realm. Professor Jennifer McIntosh stresses the need to continue investigating the deep subsurface to fully comprehend the consequences of human intervention. The introduction of new microbial communities and changes in water chemistry due to human activities like hydraulic fracturing raise concerns about the long-term implications for Earth’s subsurface.

The study underscores the significant impact of human activities on Earth’s deep subsurface. As strategies to combat climate change rely on the subsurface, it is crucial to consider the environmental consequences of these actions. Continued research and responsible management of the deep subsurface are essential for a sustainable future and to address the challenges posed by human-induced changes in Earth’s subsurface ecosystems.